Sony PlayStation and PSone Repair Reference

This page covers the Sony PlayStation: every fat console from the SCPH-1000 through the SCPH-9003 (including the Asia-only SCPH-5903 Video CD model), and the PSone, SCPH-100, 101, 102 and 103. Across NTSC-J, NTSC-U and PAL.

Two things before you read further, because both change how you should weight what follows.

First: I have never bench-tested a PlayStation or PSone console. My only bench work on this platform is the USB-C power adapter I build for the PSone, run into a dummy load, never into a console. Everything on this page is built from Sony’s service documentation, datasheets, technical wikis and practitioner writeups. Frequency claims are written as “the sources report,” and they are the community’s claims. Nothing in the data tables at the bottom is tagged bench.

Second: this console is unusually well documented, but only from 1997 on. Sony’s published service manuals start at the SCPH-5500. There are OEM manuals, schematics and full parts lists for the PU-18, PU-22, PU-23 and every PSone board, and none at all for the PU-7, PU-8, PU-16 or PU-20. So a fact about a late board can usually be read straight off a Sony drawing, while the same fact about an SCPH-1001 rests on board photographs and community wikis, and the confidence tags reflect that.

The organizing idea for this machine is that the board revision decides everything and the model number decides almost nothing. An SCPH-9001 ships on a PU-22 or a PU-23. An SCPH-7501 ships on a PU-18 or a PU-22. Every PSone model number spans all seven PM-41 sub-revisions. Chipset, modchip wiring, ODE compatibility, recap list and fuse chain all follow the board, so that comes first.

Safety first

Three hazards, and only the first one can hurt you.

A fat PlayStation with the lid off has live mains exposed. The fat console has an internal switching supply Sony calls the power block, and everything on the primary side of its transformer is at mains potential. One practitioner writeup puts the voltages inside at up to 400 V. Two details make it worse than it looks:

• The power switch does not de-energize the supply. On the 7-pin generation (PU-7, PU-8, PU-16) the power block carries a 3.5V EVER standby rail that is live whenever the cord is in. The front switch only disconnects rails from the mainboard. Treat a fat console with the cord plugged in as energized, whatever the switch says.
• There is no reason to probe a live PSU to diagnose a drive fault. Use an isolation transformer, or pull the power block and feed the mainboard from a bench supply through its connector. The pinouts for both connector generations are in the data tables below.

On the PSone, the earliest board has no fuse ahead of the switch. The PM-41 -11 sub-revision runs its DC input from the jack through a ferrite bead straight to the bulk capacitor and a 12 V zener, with nothing in series. Later boards add a 2.5 A input link, and the final -71 board a 2 A micro fuse. If you bench-feed a PSone from a lab supply, set a current limit. On a -11 the first fuse sits after the power switch, so nothing ahead of it will open for you.

Do not probe near GPU pin 10. psx-spx records measuring in that region as its “number one source for blowing up components on the mainboard” and recommends taking the same signals at the CPU side. One source, but it costs nothing to heed.

Know your board first

From the outside

Sony removed rear ports in a strict one-way sequence, so the back panel alone brackets the board.

Two traps. A 900x shell does not prove a PU-23. Units built around May 1999 ship a PU-22 with a working parallel port hidden behind the case. A 750x is not automatically a PU-22 either: early SCPH-7501 units carry a PU-18, which matters because a PU-18 takes an xStation and a PU-22 does not. Early 700x units are likewise PU-18 rather than PU-20.

The region is the last digit of the SCPH number: 0 Japan, 1 USA and Canada, 2 Europe/PAL, 3 Asia. Sony’s own mains ratings per model confirm it.

With the lid off

The silkscreen carries both the family name (PU-22, PM-41) and Sony’s board part number with a dash suffix (1-671-858-21). The suffix is the real revision.

Three corrections to the board map that circulates, the first two straight off Sony’s manual covers: PU-16 is not the SCPH-5500 (the 550x is PU-18), the SCPH-7500 series is PU-22 and the SCPH-9000 series is PU-23, and “PM-41(2)” is not a Sony designation. It is community shorthand for the late sub-revisions, identified by the 176-pin CXD2941R at IC732 where earlier boards carry the 208-pin CXD2938Q.

The quickest internal tells:

On a PU-8, count the pins on the CD sub-CPU. The early and late PU-8 carry different chipsets under one board name. A big 80-pin IC304 is an early PU-8, a small 52-pin one is a late PU-8, and that single fact changes which modchip diagram applies.

On a PSone, the model number tells you nothing about the board. Sony’s parts list carries complete-board rows for all four SCPH numbers across the whole suffix range, so an SCPH-101 can be a late -71 and an SCPH-103 an early one. The sub-revisions matter more than on any fat board, because the power tree, the fuse set, the GPU and the SPU all change inside the PM-41 name:

• -11: all-linear 3.5 V rails from two ROHM LDOs, an extra discrete 8 V stage, a heatsink, and no input fuse.
• -21 to -51: a TL594 switcher makes the 3.5 V logic rails, and a 2.5 A input link appears.
• -61: the GPU becomes the CXD9500Q with its video RAM on the die, and a 2.5 V regulator appears.
• -71: the SPU becomes the CXD2941R with its sound RAM on the die, the fuses become 1608-size micro fuses, and the ferrite bead at the jack goes.

Common problems and fixes

Ordered by how often the sources report each one. That ordering is a triage prior from practitioner writeups. Nobody has published PlayStation failure statistics. Optical-drive faults dominate the sources, which is why that section is the longest.

Won’t read discs, reads some, or reads only near the hub

Read this before touching any potentiometer on any PlayStation. The single most common way a repairable console becomes a dead one is someone turning a pot that does not do what they think it does.

• No mainboard pot on any revision sets laser power. The mainboard trimmers set focus and tracking servo parameters (and, on PU-7 per one source, sled motor voltage). Laser power is closed-loop, held by the automatic power control inside the RF amplifier.
• The PU-22, PU-23 and every PSone have no mainboard pots at all. Their manuals carry a check specification to measure against, with nothing to adjust. Any advice to “tweak the pot” on those machines describes a control that does not exist on the board.
• On PU-18 and PU-20 the one pot, RV703, is tracking push-pull balance, which is also the adjustment the copy-protection signal is read through.
• The laser trimmer the folklore means is on the pickup’s own flex cable. Two independent sources on two board generations (an SCPH-1002 and a PSone SCPH-101) put it there, which is why it is possible to turn one on a board with zero mainboard pots.

Practitioner consensus on why blind pot-turning kills drives is consistent: the pot exists to compensate for factory tolerance, and raising power to overcome a mechanical problem escalates until the diode fails, which is unrecoverable. One source reports good PSone units at 900 to 950 ohms across the flex pot; another rejects resistance targets outright. Use a resistance reading only to record and restore a factory position. Mark the original position before you turn anything, and if you cannot resolve the eye pattern on a scope, do not adjust.

The sources put dried or hardened sled grease at the top of the list, well ahead of the laser. The signature symptom is a console that only reads when tilted on its side or turned upside down. Treat the tilt as a diagnostic: if the read behavior changes with orientation, the problem is mechanical friction or alignment.

Work the ladder top to bottom. Everything above the scope step is cheap and reversible.

1. Clean the lens gently with a lightly dampened IPA swab.
2. Test with three known-good pressed discs, none of them scratched.
3. Tilt the console. If behavior changes, go straight to step 4.
4. Strip, degrease and re-lubricate the transport. Remove all the old grease, because new grease over old adds friction. Re-grease with white lithium or a silicone grease that is explicitly plastic-safe, applied to the pickup’s rail contact points so the pickup carries it along the rail. Oil the spindle motor through the two center holes on its underside only; the other holes drop oil onto the windings. Afterward the spindle should coast noticeably longer before stopping, a free bearing check.
5. Check spindle hub height and coast-down. The hub is a friction fit and creeps down the shaft. No Sony document gives a hub-height figure, and the best video source contradicts itself (0.5 mm in one video, 0.635 mm in two others), so set it by function: the disc clears the base, stays in focus travel, and nothing rubs.
6. Inspect the lens actuator’s four suspension arms. When they snap the lens sits tilted and the drive looks exactly like a weak laser. Power it with the cover off and watch whether the lens rises squarely.
7. Clean the 45-degree mirror under the objective. One screw and two side clips; one practitioner took a drive from “gives up” to playing FMV with this alone. Single-source, but free.
8. Look for concentric scuff rings on the underside of the test discs. That is collapsed rubber suspension grommets letting the disc touch the transport, and it is a reason to stop testing before you damage more discs.
9. Continuity-check the sled limit switch.
10. Read the pickup part number. KSM-440AAM, ABM and early ACM units ride on plastic sleds and glide surfaces. Service them while the rails are clean, replace them once the contact points are pitted. The sources disagree on exactly where the plastic era ends inside the ACM run, so do not scrap every ACM on sight.
11. Replace the 0.47 µF electrolytic in the CD block, C705 on PU-18 and later, C318 on PU-7 and PU-8. Sony swapped C705 from an electrolytic to a ceramic on the last PSone board, which is the most defensible reason to treat it as a priority part on any read complaint. A 0.47 µF X7R ceramic is the replacement.
12. Recap the mainboard (fat boards; see the recap section).
13. Now, and only now, scope the RF signal. Sony’s check spec on PU-22, PU-23 and the PSone is 0.90 to 1.35 Vp-p between CL704 and CL710, with a scope of better than 10 MΩ input, 0.2 V/div and 500 ns/div, on an SCD-2700 test disc. PU-18’s window is 0.95 to 1.35 Vp-p. CL710 is the Vc reference and on the PU-22, PU-23 and PSone Sony warns it must not be commoned with ground. Clip your probe ground there and every reading is wrong.
14. Below the line: adjust (PU-7 through PU-20 only, and only the pot that matches the measurement), or replace the pickup.

On sourcing a pickup, the practitioner advice is consistent: a working donor console with an original Sony drive beats a loose aftermarket pickup, and PSone donors give the best drives because they are the newest units made. A KSM-440BAM out of a PSone goes into a fat console only with spacers and, on boards that have one, a re-adjusted trimpot. A service does not rescue marginal media either: a textbook re-lube still left one practitioner’s scratched discs unreadable at the outer edge.

PSone dead, intermittent, or dies when the cable is wiggled

The sources report cracked solder at the DC jack as the most common non-optical PSone fault. The console powers only when the plug is wiggled, shuts off under vibration, or is simply dead. One practitioner attributes it to under-filled through-hole joints on a connector that takes mechanical stress.

Reflow all three of the jack’s mounting points with added solder, and while you are there reflow the controller-port ground points, which crack the same way. To confirm before you open the iron, power the console from a bench supply, flex the jack and watch the current.

After any liquid ingress at the jack, do not trust appearance. RetroSix’s water-damage teardown found a via in the power path that looked perfect and tested open.

PSone partly dead: drive spins but no picture, or no controllers

Suspect a blown fuse before a dead chip. Sony fits one-shot IC links (not resettable PTCs) on the PSone rails, and the set changes with the sub-revision:

They read open, not high, so buzz each one. Two warnings that come from the documentation disagreeing with itself:

• A widely circulated redrawn PSone schematic prints PS600 as 2.3 A and the branch fuses as 1 A. Sony’s own parts list and schematic say 2.5 A and 0.8 A. Order against Sony. Console5 notes that production boards are commonly found with 1 A parts fitted, so finding one does not make 1 A the rating.
• The -71 fuses are 1608 metric (0603 imperial) and do not interchange with the earlier IC links.

Do not bridge a blown link. The usual cause is overcurrent on the port supplies from hot-plugging a faulty controller or a third-party adapter.

The rail map localizes the rest. Two rails, MOT7.5V for the drive motors and CTR7.5V for the controller ports, leave the input ahead of any regulator. The regulated side is two parallel branches off the raw bus: a linear 78M05 at IC601 makes the audio, video and digital 5 V, while a TL594 switcher makes the 3.5 V logic rails (on everything but the -11).

Fat console dead

Check the rails at the power block connector, and check its last pin too. The last pin is the power block’s reset output, not a motor supply. Sony prints it MOUT on some sheets and RESET on others, and it is driven off the block’s voltage detector. A stuck-low reset line presents as a console that looks dead, or resets at power-on, with every rail correct. The motor supply comes off pin 1, so chasing “no motor voltage” on the last pin is a dead end.

Count the pins before you plan a power block swap. The 7-pin (PU-7, PU-8, PU-16) and 5-pin (PU-18 onward) generations are genuinely incompatible, and the 5-pin generation drops the standby rail entirely. The connector designators do not track the pin count, so count the pins.

A blown mains fuse F001 means something downstream shorted: find the short before refitting it. The fat power blocks are region-specific Sony modules with their own part numbers, and the wrong one on the wrong mains voltage is a fire risk.

One recap assumption is contested. A practitioner who opened many fat consoles reports the SMD electrolytics on the mainboards leaking on every unit, while the power block caps checked out fine, which inverts the usual “recap the PSU first” advice. It is one sample, so recap the power block on measurement or visible evidence.

Dead with every rail correct

That points at the reset supervisor. On fat consoles it lives on the power block; on the PSone it moved onto the mainboard as IC002 (-11/-21) or IC003 (-31 onward). Check that /RES releases high a few tens of milliseconds after the rails come up rather than sitting low. The same presentation can come from a dead clock: on PU-20 and later, both the CPU and GPU clocks come out of the one IC204 package, so check its supply and output-enable pins before condemning it.

Scrambled, wavy, smeared or black picture on a PSone

C550 and C551, the 220 µF 4 V coupling caps in the video output. Sony’s own PSone parts list gives both values, and the schematics put them directly in the luma and composite paths between the video encoder and the Multi Out. The sources report these two as the frequent PSone video failure. Composite dead but RGB fine points at C551; S-Video luma dead points at C550. Replace both.

Two things to check before condemning the encoder: each output also passes a 75 ohm series resistor and several are clamped by zeners, and a missing or shorted clamp can present as a dead output that looks like a DAC failure.

220 µF at 4 V is essentially extinct as a current catalog part. Uprating to 6.3 V is electrically free but costs case size, and case size is exactly the constraint under the PSone shield, so measure before you order.

No sound, or no sound effects

Split it by what still works.

• Nothing at all: the line amp IC405, its mute pins, or the 5 V rail. On PU-23 and the PSone, IC405 is an NJM2174 with two mute inputs of opposite polarity: pin 4 mutes when low, pin 5 mutes when high. Both must be in the un-muted state together. Pin 4 sits on the board reset net, so the stage is held muted while reset is asserted. A stuck-low pin 4 and a stuck-high pin 5 look identical from opposite causes.
• No sound effects and no boot chime, but CD audio plays: sound effects come from SPU synthesis, and CD audio crosses into the same SPU mixer digitally, so a working CD track clears the line stage and points into the SPU side. The documented case is an SCPH-9002 where 30 to 40 legs along one edge of the SPU had walked off their pads because the top shield was pressing on a previously installed modchip. The chip and its wiring were fine; its mounting height was wrong. Press on areas of the board with it running to localize, reflow, and check shield clearance on every modchip install.
• PU-22 is different. Its line amp has no mute pins, and it mutes with discrete transistors, so a stuck-muted PU-22 means chasing transistors.

There is no digital audio output on any stock PlayStation.

Colors wrong or monochrome with out-of-region games

Not a fault. A PAL console fed NTSC timing shows monochrome over composite and S-Video, and the reverse too. Region lockout on this console is three separate mechanisms (video standard, BIOS region and disc copy protection), and a modchip addresses only the disc layer. It does not change video timing, so a region-modded console still needs a color mod for correct color on out-of-region software. See the mods section.

Also not a fault: badly centered PAL games. The horizontal display window is set by software, and mis-centered PAL titles are documented software behavior.

Controller or memory card ports

On the PSone the four sockets sit on two 17-pin front terminal boards with a series protection network (ferrite, resistor, zener) on each line, and a dead port with intact plastic is more often that network than the socket. Sony sells only the whole terminal board.

Never hot-plug to diagnose. The 0.8 A links exist because these rails do get shorted in the field. One source reports a third-party wireless controller adapter putting the wrong voltage down a port.

Modchip installed but backups still rejected

It looks exactly like a bad solder joint, and the sources give three causes in the order they occur:

1. Wrong region build. PsNee v6 is written for PAL and silently does nothing on an NTSC console.
2. Wrong injection mode for the board. From PU-22 onward the board gates the copy-protection signal against the WFCK clock, so a chip has to chop its output at about 7.35 kHz. That chopped form is not backward compatible with PU-7 through PU-20, which expect a steady level. The mode is chosen per board revision, not per region.
3. Wrong pin. On a PM-41(2), the sync wire goes to CXD2941R pin 84 (WFCK, testpoint CL774), read straight off Sony’s -71 schematic. Pin 76 is DA07, a 7.35 kHz clock that is not locked to disc rotation, so a pin-76 install scopes right, boots backups, and then chirps and skips. Widely copied diagrams still point at 76 because one nocash table prints it. Move the wire.

And one that is not the modchip at all: a game that boots and then misbehaves (the controller stops responding, or it hangs partway in) is usually LibCrypt, a data-level protection in the disc’s subchannel Q that no modchip defeats. The fixes are an image patch before burning, or burning slowly enough to preserve the subchannel.

Powering a PSone

The jack. J001 is Sony part 1-695-565-11, printed in the parts list as JACK, DC (POLARITY UNIFIED TYPE) (DC IN 7.5V), and Sony’s block diagram labels the input EIAJ TYPE-3. Center-positive, 7.5 V DC, three independent sources in agreement. A center-negative claim circulates and traces to someone reading the DC symbol molded on the shell as a minus sign.

The plug is EIAJ-03: 4.75 mm outside, 1.7 mm inside. psx-spx prints the PSone bore as 0.8 mm inside and 5.0 mm outside, which contradicts the EIAJ Type-3 designation in its own sentence, and a 0.8 mm bore cannot seat on the jack’s 1.65 mm center pin. Aftermarket “PSone 7.5 V 2 A” listings routinely claim 5.5 x 2.1 mm, which a bench report on psxdev directly disproves. Never take barrel dimensions from vendor copy, and verify against the console in hand. The same plug is used at other voltages on other consoles, including elsewhere in my own lineup, so read the voltage printed on any adapter before it goes near a PSone.

The console-only brick Sony supplied is rated 7.5 V, 2.0 A max. In North America that is the SCPH-113, and psx-spx lists the regional siblings (SCPH-112 and 114 through 117) at the same rating. That 2.0 A is the adapter’s rating: Sony rates the console itself at 9 W.

The LCD screen changes the requirement. The SCPH-131 5-inch screen is rated 6.8 W, “not including power used by the PS one console,” and Sony’s own manual says three times to use the supplied SCPH-121 adapter only, naming the SCPH-113 console brick as one you must not use. Sony lists its Japanese sibling, the SCPH-120, at 3.0 A. No Sony document I have prints the SCPH-121’s own rating, so the 3.0 A figure for it is single-source. Both wattages are nameplate figures with no stated test conditions, and Sony does not say whether the screen’s 6.8 W is measured at the DC input or at the wall.

With the screen fitted, the console is fed through the screen. The SCPH-131 mates with the console’s Multi Out and DC jack at the same time and takes the adapter at its own rear DC IN 7.5V. So a marginal supply shows up as screen instability before console instability.

A marginal supply shows up as drive and rumble symptoms before a dead console, because MOT7.5V and CTR7.5V run straight off the jack with no regulation. And the console’s own 5 V regulator is linear, so it burns the difference between the input and 5 V as heat on the board however clean the 7.5 V you feed it.

That is the problem my USB-C power supply for the PSone is built around. It negotiates 15 V over USB Power Delivery and regulates it down to 7.5 V, rated to run the console and its clip-on screen together from one charger or power bank, with a center-positive EIAJ-03 plug. It needs a PD charger rated 30 W or more, and the setup guide covers why and how to tell when a charger is the problem.

Inside the family: what differs

Functionally the PlayStation never changes; the packaging does. Sony consolidated functions into fewer, larger custom chips roughly once a year. On a PU-8 the RF amp, CD DSP, decoder, SPU and audio DAC are five separate packages with visible traces between them. On a PSone they are one 208-pin or 176-pin part and the bus between them never leaves the die. The number of things you can probe drops with every generation, and modchip and ODE wiring moves with the packaging.

The clock architecture splits at PU-20. PU-7, PU-8, PU-16 and PU-18 use discrete oscillators: a 67.737 MHz CPU clock source and a separate 53.69 MHz (NTSC) or 53.20 MHz (PAL) GPU oscillator. From PU-20 onward a single crystal (14.318 MHz NTSC, 17.734 MHz PAL) feeds a Cypress CY2081 PLL at IC204 that makes the CPU clock, the GPU clock and the color subcarrier. No Sony document covers the PU-20, so that boundary is established from board photographs, and it is the boundary the color mods follow too.

Region is three separate things, and they fail and are defeated independently:

• Video standard, set by ordered parts: the CY2081 variant and crystal on PU-20 and later, the oscillator on earlier boards. There is no reference for the other region anywhere in the console.
• BIOS region, set by the mask ROM at IC102, ordered per region.
• Disc copy protection, enforced by the CD sub-CPU at IC304, whose mask number also encodes the region.

The copy protection lives in the drive, not the BIOS. Original discs carry a four-letter region string (SCEI, SCEA, SCEE) encoded as a sideways wobble of the recorded track itself, in the lead-in at the innermost radius, and the console reads it off the tracking signal. A modchip does not reproduce the wobble; it drives the DSP’s input with an electrically different signal the console accepts anyway, at 250 bits per second. Multi-region chips cycle all three strings, which is why a modded console can take a few seconds longer to boot. That delay is the design.

The PU-16 / SCPH-5903 is the outlier. A white-shelled Video CD console sold in Asia outside Japan, based on PU-8 hardware with an MP-45 daughterboard, three multiplexers switching audio and video between the PlayStation and VCD paths, a 1 MB BIOS, and two video DACs. No modchip diagram has been published for it, and three electrolytics near the daughterboard are reduced-height tantalums to clear it, which matters if a cap kit gets fitted blind.

The PSone deletes the internal power supply, the serial port, the parallel port and the reset button (the power button doubles as reset on a quick double press). The serial signals survive as solder pads below the CPU.

PM-41 RGB completeness is a sub-revision lottery. psx-spx records the 1-679-335-21 board as having incomplete RGB on the Multi Out and the -51 as complete, and does not know which signal the -21 is missing. That is one source, and it decides whether a given PSone can be sold as RGB-capable, so check the actual board before advertising it.

Mods worth knowing

The rule that governs all of it: the modchip signal set does not sit on the same silicon across revisions. The copy-protection data point moves from an 8-pin comparator on PU-7, to a 16-pin part on PU-18 and PU-20, to SPU pin 42 on PU-22 through the PSone -61, to SPU pin 36 on the PM-41(2). Wiring one revision’s diagram into another board is the most damage-prone mistake in PlayStation modding. Read the silkscreen before you read any diagram.

Modchips

PsNee is the open-source default, on AVR. The ATtiny parts are small and cheap but cannot do the BIOS patch; the ATmega parts can. So ATtiny for a US or Japanese fat console, ATmega for a PAL PSone. One documented quirk: on the SCPH-7000 its BIOS patch breaks memory cards, and the only workaround is a switch to disable the patch.

“Stealth” is a wiring requirement. Later games detect a chip by querying the drive’s copy-protection counters after boot, when a real disc would be silent, and refuse to run whether or not the disc is a copy. A stealth chip transmits only at power-up and on a lid open. The PIC-family chips sense the lid through IC304 pin 19 on the 52-pin sub-CPU, which is why they need a lid wire; PsNee gates on the disc position instead and needs no lid wire. On PU-7 and early PU-8 that pin is a crystal node on the 80-pin part, so the PIC-family lid wire goes to a board pad instead.

Two things to disclose on a modded unit: the boot delay on multi-region chips, and the “boots on the second try” behavior of chips that run on an internal oscillator (MM3, OneChip). Both are design behavior, and both read as faults to a buyer who was not told.

Optical drive emulators

A PlayStation with a worn laser is a low-value shell, and an ODE both removes the wear item permanently and adds a premium. The catch is that almost every ODE is gated on the board revision:

PU-20, PU-23 and the PSone are the gaps. The PU-20 takes neither an xStation nor a MODE, and a PU-20 SCPH-700x looks identical to a PU-18 from outside, so check the silkscreen before buying a donor. PSIO needs the parallel port that the PU-23 and PSone deleted.

The widely repeated “early PU-8 is incompatible with xStation” line is stale. The vendor’s own wiki has carried an early PU-8 install guide since 2022, and a manufactured early-PU-8 board is photographed in its repo. What remains true is that stock of that board is scarce.

ArcStation is the only ODE that reaches the PSone, because it recreates the analog signal off the pickup instead of tapping the digital CD bus. It is vendor-stated and corroborated by two trade outlets, but nothing about it is bench-verified in any source I have, and two features (the virtual memory card and gamepad reset) are listed as not available on the PSone.

Two PSIO notes worth carrying: its switch board’s maximum input is 3.3 V, so do not solder it to a 5 V rail, and Cybdyn states that aftermarket replacement power supplies fail to trigger the reset signal PSIO depends on.

Video

PS1Digital is a digital-to-digital HDMI board that taps the GPU’s 24-bit bus, and it fits the PU-18 and PU-20 only. The sources call it the largest single value-add on a 550x or 700x, and the reason to prefer those two revisions at the low end of the used market. It is advanced work: four flex cables, the serial port removed, and a GPU flex that is the whole job. It carries its own PsNee and defaults to dual-frequency operation, so do not add a second modchip or DFO.

RGB is mostly a cable question. The Multi Out already carries analog RGB on pins 1, 2 and 4, with sync riding on the composite pin, and there is no component video on a PlayStation. A PS2 or PS3 component cable in a PS1 carries RGB on those three lines and needs sync added from pin 7. Third-party cables populate only the pins that cable needs, so a cheap composite cable cannot be re-pinned for RGB.

The PAL/NTSC color mod is two different mods, split at PU-20. On PU-20 and later the color clock is already stable, and forcing the encoder’s NT/PAL input (IC502 pin 13) to ground or supply is the whole job. On PU-7 through PU-18 the GPU derives the subcarrier from the frame rate, so the fix is an external 4.43 MHz or 3.58 MHz oscillator into the encoder.

On a PSone -61 or -71, do not follow the “lift GPU pin 157” recipe. From -61 onward the GPU is the CXD9500Q, its color-select pin is 63, and pin 157 is a ground. Lifting 157 does nothing to color and lifts a ground return off a 208-pin QFP. Work the IC502 pin 13 end on any PM-41; it is a bare trace on every board in that group.

A color mod can also break color on a modern display: one source reports several LCDs that accept NTSC 4.43 but not PAL60. Ask what the display is first.

A DFO (dual-frequency oscillator) fixes frame timing as well as hue. Without one, NTSC games on a PAL console run at about 59.3 Hz and PAL games on an NTSC console at about 50.3 Hz, which upsets some scalers and speedrun timing. Published install diagrams cover PU-18 through the PM-41(2).

Audio, saves and reset

• TOSLINK / S/PDIF taps the I2S bus into the audio DAC, and SCPH-750x and later have no discrete DAC to tap, so it is not possible on those.
• MemCard PRO: SD-backed virtual memory cards whose images are raw 131,072-byte .mcd files, interchangeable with emulator saves. Sell it alongside rather than installed.
• In-game reset: an open-source PIC board that reads controller port 1 and pulses reset on a button combination, with a long-pulse combo added for xStation. The natural companion to any ODE.

Recap and parts

The headline: the PlayStation is not a universal recap candidate, and the split is by generation. Two practitioners who opened many units point the same way: every fat mainboard one of them opened had leaking SMD electrolytics, and the other found no convincing evidence of leakage on PSone boards. Each is one person’s sample, but they agree with the manufacturing dates (fat boards 1994 to 2000, PM-41 2000 to 2004). The working rule: recap fat mainboards as standard, recap a PSone only on evidence.

Things to carry into an order:

• Every electrolytic on every PlayStation mainboard is surface-mount. All the radials live in the fat power block. Some Sony parts lists write chip electrolytics as a bare CAP, ELECT, which is a part-number-family habit that says nothing about mounting style.
• The count falls steeply: 38 electrolytics on a PU-7, 19 on a PU-22, 13 plus 4 tantalums on the last PSone. Read the board before you buy the kit.
• Leave the tantalums alone. PU-23 and the PSone carry several solid tantalums (C736, C737, C738, and more on the PSone) that do not dry out. Console5 annotates C617 on early PU-23 boards “do not replace.” If one has failed short, replace it with a tantalum or polymer, never an aluminum electrolytic.
• Diameter and height both matter, because everything has to clear the RF shield. A modern low-ESR part of the same value is often a larger can than the 4 mm part Sony fitted. The board-specific kits are pre-sized for that, which is their main advantage.
• Budget a drive re-check after a fat-board recap. One practitioner records drives performing worse after a recap, because new parts shift voltages the servo was compensating for. On PU-7 through PU-20 that means re-checking the RF levels.
• No PlayStation mainboard has thermal paste. No parts list has a thermal pad or compound, and the shields are not in contact with the chips. Adding paste is an unvalidated change to the design.

The parts that actually fail and are hard to buy:

• The CD motor driver IC722 is now broker or donor only, on either generation. Sony lists both ROHM BA5947FP and BA5977FP at that designator on the PSone, so read the marking on the chip rather than inferring it from the board. As of September 2026 the BA5947FP is marked obsolete at DigiKey and the BA5977FP has no DigiKey listing at all.
• The 5 V regulator IC601 is the one active part still in the catalog, as onsemi’s MC78M05CDTRKG. The PU-23’s Toshiba TA78M05F numbers its pins differently from the onsemi part, but Sony wires both in the same physical lead order, so fit a replacement by signal (input lead, ground tab, output lead), never by datasheet pin number.
• Everything with a Sony CX prefix, the BIOS ROM and the CD sub-CPU are donor only. The sub-CPU’s mask is region-keyed, and a donor must carry the mask the target board’s parts list calls for. The PSone -71 uses a different set that does not cross to earlier boards.

The hard data (per-revision cap lists, the fat power block cap sets, the fuse and connector parts, the pinouts and their confidence tags) is in the sections that follow, organized by board because that is what decides the job.

Capacitor lists

Per board and per sub-revision. The PSone lists come straight from Sony’s parts list; PU-23 comes from Sony’s list with voltages carried across from the PSone list on matching part numbers; PU-7 through PU-22 come from Console5 alone, because Sony published no usable list for those boards. The fat power blocks are their own population and are listed separately by Sony part number.

Replacement parts

The non-capacitor parts a PlayStation job consumes, and where each one actually comes from in 2026.

Chip & connector pinouts

The component library: each connector and IC defined once, with a pin table and, where the package geometry supports it, an interactive diagram. The revision badge on each card shows which boards it applies to. Large chips carry only the pins a repair or a mod turns on; the rest show as uncaptured.