PC Engine GT - Replacement HuCard Slot Board

[MuNaught]

I have solved the button input issue:The I and II sliders were not making contact. I bent the pins up and cleaned them and the face buttons are all working now.

The audio issue was also solved: After much troubleshooting the usual causes, I eventually determined I have a failed volume dial potentiometer. I swapped in a DMG GameBoy potentiometer and now the audio is loud and perfect! Unfortunately the DMG pot is too thick for the PCE GT, so this is not a permanent solution. I haven't had success tracking down a pot of the same size originally used in the TurboExpress / PCE GT. Does anyone know where to find one?

Once I get this addressed I will button it up, and turn my attention to validation of the region free HuCard slot board. I have all of the parts on hand to put them together and test.

[tawy]

https://aliexpress.com/item/32968867573.html

DMG and GBA/GBC pot are the same, if you look the design, the only differences between the two are a bit of plastic to make the DMG wheel version thicker.

[MuNaught]

The GBC/GBA pot does function, and I have sound again. It is a slightly different offset, so I clipped the anchor points and relocated them. The only negative is it appears to be a different resistance range (10k ohm) from the factory original, which means volume does not go all the way down to zero. I am not concerned about this, it's functioning now, and I consider that a win.

I grounded pin 29 on the C6280 as required, wired the select button to the region-free HuCard board, and everything works perfectly. I am able to boot PCE games normally, and can boot TG16 games when holding "Select" during power on.

This is orders of magnitude cleaner and less destructive than previous region free mods that required cutting the HuCard slot pins and a rat's nest of wires.











At this point, everything is functional.

[MasterofBiscuits]

Awesome work, looks like a great option for a region mod/ damaged cart slot.

[24masks]

This looks amazing! And the progress for it seems to have gone smoothly.
I have a PCE GT that has a HuCard slot that was completely wrecked by battery acid, causing some of the pins for the FFC connector to quite literally flake off. 
Here's an image of it
https://imgur.com/a/20yVFrH
This would be the perfect solution to my sad GT.

I'd be very happy to order this replacement PCB whenever they are ready for selling. 

[MuNaught]

Yes this would be a good solution. Are you thinking standard replacement or region-free?

I am open to the idea of beta testers as well. Right now I just have a sample size of one.

What do you feel your soldering experience is? This repair/mod is advanced, ~0.4mm pads so you will want a tip such as the T15-JS02 and needle probes for you DMM.

[MuNaught]

I have a lot of irons in the fire right now, but I do fully intend to put both the direct replacements and the region-free boards up for sale in the future. I don't expect there to be significant demand, but for those who are repairing an otherwise salvage console, this could really help. I have already sent out a few early release samples to some folks.

[tawy]

https://jt-studios.com/product/38pin-pc-engine-connector/

[MuNaught]

A new version of the board. It is functionally identical, just a new prettier style. I am still building these upon request, so if you are interested, contact me here or on Twitter (@KytorIndustries).

[tawy]

The GBC/GBA pot does function, and I have sound again. It is a slightly different offset, so I clipped the anchor points and relocated them. The only negative is it appears to be a different resistance range (10k ohm) from the factory original, which means volume does not go all the way down to zero. I am not concerned about this, it's functioning now, and I consider that a win.

I had the same issue repairing a pot last week.
You have to short 1 with 1 and 2 with 2 (if you think a little bit, it's obvious ^^), if you dont do this, your headphone output will always be very loud and the volume will never go to zero on speaker.
Shorting these input means that the GT cannot handle stereo output :-/