Buggy Duo Pics

[Slypty]

Replaced all caps and checked traces/vias on this Duo, checks out can't find a fault. 

  But this is what the screen looks like.  The last image is with a game in the Hu Slot (tennis)

With out a game it flashes between the first two pics.
https://drive.google.com/file/d/1c_zuTpCaM1SQz6FVlFdDdAFzRqBIt1zq/view?usp=sharing
https://drive.google.com/file/d/1c_zuTpCaM1SQz6FVlFdDdAFzRqBIt1zq/view?usp=sharing
https://drive.google.com/file/d/1mLt1Et6VHPGz-WbmO3n6Xe5ihp2t4rzs/view?usp=sharing

[Keith Courage]

Unfortunately that's most likely a Bad chip on the motherboard or a bad trace. Looks more like bad ram but could also be one of the 3 Hu chips.

[Slypty]

Trying to source a cheap IC replacement source, anybody know a store or supplier for the IC516 to IC520? 

  I've removed IC520 to disable the CD side and try to enable HuCards but that didn't work.  Two of the IC's are running hot, hoping a replacement does something.  Also tested IC516 with a logic probe and was getting opposite of the recommended readings.  For instance, I'd get High readings when Low is indicated on the schematics, and vice-versa.  5V points were fine.
 
  Finally after reflowing Hu6280 the picture went back to completely white again.  I may have a short somewhere else as well but starting here.

[Nodoka75]

If you talk about the TTLs 74F32, 74ALS244 and 74ALS245 in SOP/SOIC packages, any electronics supplier like Mouser, Digikey, etc. can provide you these chips. On my DUO there are Texas Instruments, but other brands have these logic ICs.

[thesteve]

odds are its actually open connections between the HuC6270 and its ram chips
the traces open up where they pass through the board

[Slypty]

Managed to source the chips from eBay, will be waiting a month to get them.  Thanks for the tip on 6270 Ill check traces while I wait patiently