USB-C 7.5V Power Adapter for NEC TurboExpress & PC Engine GT

Power your NEC TurboExpress or PC Engine GT with modern USB-C — no PD required

Ditch the long-dead battery pack and the impossible-to-find original power brick. This is a brand-new, custom-built power adapter that lets you run your NEC TurboExpress (or its Japanese twin, the PC Engine GT) from almost any modern USB power source. As a fellow enthusiast, I designed this one to be the polished, foolproof way to keep one of the great retro handhelds alive.

Transparency matters to me, so here’s exactly what you’re getting: these adapters are hand-built in small batches to one consistent spec, so the photos are representative of what will arrive — same components, same enclosure, same build, same testing, unit to unit. The only thing that varies is cable length (about 6 to 18 inches, depending on the barrel jack I have on hand); if you need a particular length, just ask before ordering. Your satisfaction is what matters most to me, and I’m always glad to answer questions before or after a sale.

What’s included

• One (1) custom-built, enclosed USB-C 7.5V power adapter for the NEC TurboExpress / PC Engine GT.
• Adapter only. This does not include a USB-C power brick, a USB-C cable, or a console.

The modern power solution — and why it’s better

The TurboExpress and PC Engine GT were designed around a 7.5V regulated supply (the original NEC adapter is rated 7.5V at 1.25A) — an awkward voltage that no off-the-shelf USB-C source provides directly. Instead of relying on a fussy USB Power Delivery (PD) negotiation, this adapter contains an efficient onboard boost converter that takes a standard 5V USB input and steps it up to a clean, regulated 7.5V — exactly what these consoles were built to run on.

Because it only needs 5V in, it runs on practically anything: phone chargers, laptops, power banks, car ports, and plain “dumb” USB-A bricks. No PD handshake, no compatibility roulette.

Built and tested by hand

• Enclosed and labeled. A case 3D-printed in commercial-grade ASA — a UV-stable plastic that won’t yellow or get brittle — with captive nuts holds everything together, clearly marked with voltage and polarity — it looks and feels like a finished product, not a hand-wrapped cable.
• Foolproof internal strain relief so the solder joints never take a pull.
• Runs cool. Under load the boost board peaks at about 33 C — barely above room temperature. That is what high efficiency looks like.
• Verified on the bench. I validate each design under full load and for ripple; every unit then gets a final output-voltage check before it ships.

Compatibility

Uses a center-positive, right-angle 3.5 x 1.35 mm barrel jack, built specifically for:

• NEC TurboExpress
• NEC PC Engine GT (the Japanese equivalent — identical power input: same 7.5V, same plug, same polarity)

Please note: do not use this adapter with an original Game Boy (DMG-01). It shares the same plug size but uses the opposite polarity and a lower voltage. The labeled enclosure is there specifically to prevent that mixup.

An excellent troubleshooting step

Seeing display issues, audio buzz, or unreliable behavior from your TurboExpress? Those symptoms are often caused by aging power circuitry or a marginal power source. Feeding the console clean, correct, regulated voltage is a great first step: if the issues clear up, your old power source was the culprit; if they persist, it is a strong sign the console itself needs internal servicing (these units are well known for needing a re-cap).

Custom orders & bulk pricing

Buying more than one? Get 15% off when you buy two or more — mix and match any of my dongles — and they ship together, so you save on shipping too. Need a larger quantity or a custom build? Send a message — I can accommodate specific cable lengths, different barrel sizes or polarities, and other output voltages (5V, 7.5V, 9V, 12V, 15V, or 20V).

About the maker

I’m an electrical engineer and long-time hobbyist with a passion for vintage electronics, especially classic video games. The items I sell are projects from my personal workshop. All items are guaranteed working on arrival and in the state described. Thanks for looking.