PC engine gt ,, only screen lights up

ok I removed the gray thing too , some weird components underneath it

i saw a YouTube clip of a guy saying in description that he saved one like this by recapping and replacing d502 , which i can't even locate

 

Remove the (SI M on top) D500 component the butcher "replaced" check for damage of the component and the traces.
Replace the component if needed.
I think "the weird components" are coils / inductors ?

Be careful !
It is the high voltage section ?

D502 ?
https://ibb.co/fvgG6hr

quote:
"Ok so it wouldn't show video, but it had sound after the recap.
Taking voltage measurements was kind of a shot in the dark since I had no schematic!
But I found that D502 had one of it's two diods bad! And now it works!"
Source:
https://www.geektronics.info/index.php?topic=25.0

In atypical NEC fashion, many part designators have not been printed on the silkscreen, or are printed underneath other components.

The metal shield you never got from the butcher.
Is it a RF shield, or also a heatsink ?

So now you get sound ?
So it boots ?
If so, you are on the right track (hopefully), keep going, keep trying.
Let it go for a moment, and begin again refreshed, with a clear mind.

https://robertjrgraham.com/wp-content/uploads/2011/05/spock-logic-begninning.jpg

But the display does not show anything ?
Like the backlight is not working, or no video signal to the display ?

Check continuity on Connector CN201 ?
Replace the connector ?
looks like a "standard" connector used in many more devices to connect a flat cable.

https://console5.com/wiki/Turbo_Express

Good luck !

 

thaaaanks again and again

as answers to your questions ,

yes it boots, 3 games tested , they are working, sound very loud and clear

buttons some works, right button, run , they work, but that doesn't Matter i can fix that later.

screen light working, also it did behave funny with some lines , once maybe , with moving it left and right , connector looks connected well, i did many times sand paper in its connector slot.

now can I accept this console for my intended mods?

3.5 screen mod with AV chip installed
rgb out to tv, i bought rgb chip and as far as I asked some guys it should work
controller port mod

all these parts already purchased and they are on the way

so is there any chance that av and rgb will work even if old display doesn't work?

i have to make a good choice as i still can return this item, which iam not in favor of..

 

I need some more info about the modifications you are talking about.
What the .... is this ?
https://ibb.co/82xK4bp
https://ibb.co/FJjbQ6q

The butcher removed all shielding also around the transformer near D502 ?


Difficulty level 11+ ?



GOOD LUCK !!

Remove the grey goop, some insulators become conductive after years !

"screen light works"
So the high voltage section works .....
"funny with some lines , once maybe"
So GPUs video output works....or ?
No screen output at all ?
Blown components between the GPU and the connector, or is it the display it self ?
Fused ? doubt it ....

I hope (for you) the GPU chip is working because the 3,5" mod takes outputs straight from there.

Region mod ?
http://www.multimods.com/SlotMod1.html

Hu6280 is for audio / CPU ?
https://console5.com/wiki/Hu6280
http://archaicpixels.com/HuC6280#Pin_assignments

Hu6260 is the GPU ?
https://console5.com/wiki/Hu6260
https://gamesx.com/rgbadd/rgbturbo.htm
http://archaicpixels.com/HuC6260#Pin_assignments

Hu6270 is a video display controller ?
https://console5.com/wiki/Hu6270
http://archaicpixels.com/HuC6270#Pin_assignments
https://en.wikipedia.org/wiki/Hudson_Soft_HuC6270

Same pinout as a Turbo Grafx 16 ?
Parts of this schematic usable ?
https://console5.com/wiki/File:TurboGrafx-16_Unit_Service_Manual_-_SMTG16.pdf

 

looool , i really liked that level 11

yes you are right , challenge accepted

i did dreamcast dual bios mod , xbox360 modchip with all the irritant wires, i hope i can live with this , lol

not sure if the screen board is fused, opened it to check cable is fixed, but not sure if its fused ..

so if I may know please, what are the full part numbers of d500 and d502 , i will just buy & replace directly..

butcher did not remove the shield of the transformer , lol
thnx again

 

Sorry I can not help you out with part numbers or values of d500 or d502 or other parts.

Once again, GOOD LUCK !!
Take your time !

 

thank you

so does anyone have such schematic or list or file anything with parts numbers etc?

 

or is there a service manual out there ?

 

None that I could find.

Once again, good luck !



Could this help ?
https://www.aliexpress.com/item/LCD...85-420c-97d2-72fddd312770&transAbTest=ae803_4

Test Ranges:

Inductors/capacitors/diodes/dual diode/ mos, transistor/SCR /regulators/LED tube/ESR/restistors



https://gamesx.com/wiki/doku.php?id=schematics:pcenetlist




So it could be diodes, capacitors or broken, damaged traces.

 

Thanks alot

 

Where are you located, I may be able to work something out. I’ll check the diodes on the one I already parted out

 

thanks alot , Iam in the other end of the world, lol , Bahrain

i don't have a tv tuner unfortunately, but i do have a plan , expecting some chips tomorrow and I will know for sure whats going on, mean while i would love to know the parts or have them as a second option if things are not going well.

 

Wouldn’t matter anyways on the tv tuner, sound means the games boot. In both of my cases the tv tuner worked perfectly but games wouldn’t boot, both booted games prior to recapping

 

mmm , so I got an advice from someone that if a recap doesn't work, then repeat it, have you tried that?

 

Haven’t had a chance but plan too with a different supplier

 

ok , i tried now getting rgb out via scart , using mickris rgb chip, i keep getting this , scart end wires are right , tighted 8 & 16 with 100 ohms resistor to a + of a capacitor on the motherboard, still not working correctly, gpu is working its a messed up picture , the console is working, sound via its own speakers, even in the shadow i can it working, still did not install the chip of av

rgb chip assembled by me as they supply it with parts loose

 

also the rgb chip is getting too hot , is this normal?

 

ok , the so called level 11 is done , cant say it was a piece of cake to left all those legs, but its done thanks God.



the problem is the RGB out

second problem is after a few minutes of crisp display screen got a bit darker , and a few flickers , notice the speed down left corner, its not clear anymore !! why ...it was good for 3 minutes !!

 

i was trying to share a video which i have on onedrive but it seems not allowed

there some graphical glitches

unknown why

could it be the ribon cable between motherboard and hu reader ? i bent it alot

 

also graphics issues with unstable av out in jack nicklaus golf