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NEC / Hudson GPU

Pinout source: TurboGrafx 16 Service Manual Schematic


Jailbar / Vertical Bar Fix

Original credit for this modification: Tim Worthington

Under certain circumstances, vertical bars may be visible on PC Engine / TurboGrafx consoles. This is due to insufficient capacitance on the analog and digital 5V supply for the 6260 chip.

The solution is to increase the capacitance on each 5v supply rail. This is easily accomplished using modern surface mount capacitors.

To simplify the location process, our notes below list one set of visible caps are are farthest from other parts. On many PCBs there are actually 3 per 5v rail to choose from [1].

As of February, 2017, all of our cap kits and RGB kits come with 2 surface mount ceramic caps to perform this simple modification! We also supply these caps in bulk quantity.

Jailbar Fix Locations

Non-CD Systems

PC Engine (Original, White)
C134 and C120
PC Engine (Original, White) Later PCBs
C121 and C135 (See Core Grafx photo below)
PC Engine Core Grafx / Core Grafx II
C121 and C135
PC Engine Shuttle
Replace C134 and C133
TurboGrafx 16
Add cap in parallel between the legs of ceramic disc caps C128 and C137
Replace C168, C169

Handheld / Portable Systems

Turbo Express
C709 and C715. Improves quality of LCD modded units.
PC Engine LT
Might not be necessary, unsure of original parts as the LT 5v rail cap arrangement is different from other PC Engine hardware. See image for possibilities. The LT appears to have 1 or 2 factory caps per rail but we don't have an LT to run continuity checks on.

CD-based Systems

Turbo Duo (PWA-3321-A)
C923 and C908
PC Engine Duo (PWA-3321-A)
C923 and C908
PC Engine Duo-R (PWA-3339-A)
C903 and C909
PC Engine Duo-RX (PWA-3365-A)
C903 and C909


C526 and C529

RGB Buffer / Amplifier

Discreet Component Version

The discreet parts kits are no longer available, but we do carry a few alternatives

Hu6260 RGB amp schematic
Pinout for 2SC1815 - E C B

RGB signals are present in TurboGrafx, TurboDuo, PC Engine, etc. consoles but need to be buffered. Attempting to drive a monitor directly will likely result in image loss or sync loss on high brightness images.

  • Parts List:
    • 2SC1815 (x4)
    • 10KΩ (x8)
    • 300Ω (x1)
    • 75Ω (x4)
    • 10Ω (x3)
    • 220µF, 6.3v (x4)
    • 10µF, 10v (x6)