Based on your screen shot, it appears the Diagnostic Bios is confirming what the UNI-BIOS was showing before an error in the upper backup ram segment. The system is sending out a series of bits and is expecting to see the same bits returned. In your screen shot the first 2 digits of are coming back incorrectly. If I am not mistaken the first 2 digits are sent to the Upper RAM chip and the other 2 go to the Lower RAM chip.
The readings you show for the HC32 and the D4990a don’t look bad, the discrepancies on some of the pins could be a broken trace or a failed RAM Chip (there are only 2).
- If you haven’t done so already I would remove the battery, clean the area, remove any left over solder flux or residue and use a meter and magnifying lens to look at the traces on both sides of the board.
- If you have a donor board you could try swapping the RAM out. If you had to buy new RAM it shouldn’t be too bad price wise, I just picked up some replacements for about $2 ~ $3 a chip including shipping on eBay. But before you spend any money I would troubleshoot further.
- just a word of caution when you begin working on these boards and your removing or changing components be careful not to create more trace damage. Use good solder flux to promote heat conductivity. Take your time cleaning the area with some good isopropyl at least 70% or better (I use a 99% Isopropyl).
Hope this helps.
Anyone else out there please feel free to correct me if any of the above is incorrect.
