Author Topic: My Pc Engine GT suddently has color issues (purple boot)  (Read 400 times)

mtd

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My Pc Engine GT suddently has color issues (purple boot)
« on: January 19, 2024, 02:59:37 AM »
Hello guys
i hope i can find some help here  :pray:
My GT had some issues with the -25V and could not produced a correct voltage for the lamp. When sometimes it decided to properly work, however, the unit was working and i did not have any problems, it was previously recapped by me with ceramic smd's.

I then decided to LCDDRV the unit, and after the installation it worked fine 3-4 circles (on/off) then it keeps having this color issue that i cannot figure out. I have a purple screen with no game and wrong/missing colors with it. The kit comes from Aliexpress.

I checked the voltage, Q502 is 4.8V, however raising it or lower it with VR501 pot did not change my problem. I also wonder what is the proper voltage for that pot  :-k

Are there any common fails on this lcddrv chinese clones or mu GT has developed some issues? Maybe with 6264 srams, are they responsable for the video color?
i cannot find someone with my same problem, hopefully some of you can help me with it.
Thanks

https://ibb.co/Lk15FW0
https://ibb.co/hDMr0Z8
« Last Edit: January 19, 2024, 03:06:43 AM by mtd »

Keith Courage

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Re: My Pc Engine GT suddently has color issues (purple boot)
« Reply #1 on: January 21, 2024, 02:19:02 AM »
Can you still hear audio for games when the system is powered on even though the screen is not displaying correctly?

mtd

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Re: My Pc Engine GT suddently has color issues (purple boot)
« Reply #2 on: January 23, 2024, 02:14:49 AM »
Can you still hear audio for games when the system is powered on even though the screen is not displaying correctly?
Yes i can but the audio is very low at maximum level...

Keith Courage

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Re: My Pc Engine GT suddently has color issues (purple boot)
« Reply #3 on: January 23, 2024, 05:59:07 PM »
Well this is a good sign as we know the system is still working. The audio issue has to be due to bad connections for the capacitors near the headphone port or that the headphone port itself is damaged.

Anyways, the screen you have might have just gone bad. Well maybe the screen itself but it could also be the PCB controller board for the screen. I've installed many of the LCDDRV screens from aliexpress and I did have 1 that showed up faulty but that was out of maybe 200 or more of them that I've bought so far.

The bummer is the company on Aliexpress will want you to ship the screen back to them for a replacement or refund. They don't just refund without a return.