Trying to repair it i killed my Core Grafx II

[Koolhass]

Hello guys!

Lately i'm in a bad luck strike! XD. i have a PC Engine Core Grafx II sitting in home waiting for a SSDS3. I finally got one, only to discover that my console has a problem. I have a original PAC LAND HuCard, and the game works flawlessly. However, other games such a Youkai Douchuuki have minor or heavy graphical glitches, rendering them impossible to play

Also, SSDS3 shows the same errors, and CD games won't even past the "press run" screen

Bonker looked like this:



I began troubleshooting RAM modules and HU C6270.  Reflowed RAM and stayed the same. However, when i reflowed the Hu C6270, seems to be that i shorted / overheat something, the proble got worse and then the console onlye shows a white screen. I only applied solder flux and reflowed the connection pins.

How to test if i really killed that module?  I ordered a RAM replacement and i'm trying to buy some bad pc engines to remove and replace parts.

[Keith Courage]

Do you get a plain white screen with or without the SSD on the back as well? Just wondering if you were only testing with a HU card in which case one of the Card slot wires may have come loose inside the system. This would not effect SSD use though.

Also, double check that none of the pins in the rear of the core grafx got pushed in. IF so, you can pull them out using a small pair of pliers.

[Koolhass]

Do you get a plain white screen with or without the SSD on the back as well? Just wondering if you were only testing with a HU card in which case one of the Card slot wires may have come loose inside the system. This would not effect SSD use though.

Also, double check that none of the pins in the rear of the core grafx got pushed in. IF so, you can pull them out using a small pair of pliers.

Thanks for the response!! I get a white screen with the HuCard and composite video, and also with the SSDS3

The pins are all perfect, cleaned the contacts and no signs of corrosion or anything related.

Here is also a picture of the board, no broken traces at sight

[Keith Courage]

Well that stinks. Pretty sure you have a dead Hu6280 chip on the board then. Usually not worth the cost of having it replaced since the only place to get another chip, is from another game console.

[Keith Courage]

Just looked at your pics again. Is it me or is there no solder on the pins for one side of your ram chips? IC106

[Koolhass]

Yes!, today i  bought a heat gun station to properly remove the rams and the HUC6270, clean the pads, find hidden broken traces, resolder them and give it another go. I'll post the results. Also, i bought a junk PC engine, i'll see if i can make a working one with parts of both.

[Koolhass]

Here some news. I desoldered both ram and HuC6270. I couldn't find any broken traces or glaring problems, so i solder them back again, and the only thing that i get are scrambled graphics. 

Anyway, my replacement PC Engine arrived, to my surprise, it's in better shape than the old one, i can play almost everything, only with one annoying graphic glitch, check it out:







Some games are missing chunks of sprites!

A quick visual inspection, anything looks out of ordinary



Backside, only thing i noticed is this rusted area on the back shield and PCB





Also swapped RAM sticks, but the problem remained the same. Any ideas where to troubleshoot?