glad to see that my work interest people
pcegt opened, minor correction made, continuity check done.
@Keith, i did use your schematic to do what i needed to do :
https://www.pcenginefans.com/forum/index.php?topic=23503.msg523412#msg523412I can share the pinout for the controller board, it follows the controller line, minus the 2 for the speakers and 2 for comlink :
1 : VCC
2 : HU6280 22
3 : HU6280 24
4 : HU6280 25
5 : HU6280 26
6 : HU6280 31
7 : HU6280 32
8 : timeout disable ?
9 : comlink ?
10 : GND
11 : spk1
12 : spk2
every line has a resistor between the chip and the pin, doing a test with a motherboard standing up is not easy
@necromancer & @keith, i think you can help me doing something on my gt, i did a lcddrv mod on it (for now it fits my needs, i dont need more if i cant "integer scale" the video). do you know how to adjust the brightness of the screen using the external wheel ?
I think it is possible to put a 3.5 IPS screen with VGA input. The PC Engine have RGB + Hsync and Vsync, needed for vga and used (i think) on some external video hdmi output for pcengine.
It will be a cheaper solution for a great screen. Those screen drivers board use 12V instead of 5, but a DC-DC step up converter can be use. and maybe a hw hack can be made to input 5V on the driver board. the component around the DC input seems to be voltage regulators. nothing uses 12V, RTD2660 is 3.3/5V powered and the ips screen too :
aliexpress.com/item/4000543740241.html
i'm pretty sure the connector i have desolder on my GT (CN201) use RGB line + Hsync and Vsync. if this is the case, a plug and play mod can be done, with just a little pcb to make.