Ich habe hier ein 250407 REV C, das scheint zu funktionieren aber während der RAMTEST2 lässt xFF auf der display und kommt nicht weiter.
Tests
Multimax & Kickman Carts Laufen OK
DEADTEST alle tests OK
Mainboard
250407 REV C mit 3x MOS IC (U13/U25 MOS 7708, U14 MOS 7709)
Video
[Externes Medium: https://youtu.be/8gM8WBwwBok]
Before ich ähnungslos U13/U14/U25 ablöten, möchte ich euer meinung was passiert hier.
Code
- 5.5 RAM TEST 2
- RAM test 2 does a memory test on locations $3000-$FFFF. Before RAM test 2 is ex-
- ecuted, the diagnostic program is transferred from $8000-$9FFF to $1000-$2FFF.
- RAM test 2 writes Hex 00, 55, AA, and FF into locations $3000-$FFFF. After a refresh
- cycle occurs, the data is read and compared to written data. If DATA READ = DATA WRIT-
- TEN, RAM test 2 is 'OK'. If DATA READ * DATA WRITTEN, RAM test 2 is 'BAD'.
- If RAM test 2 fails, and only 1 RAM IC is displayed 'BAD', it is usually an indication
- of a stuck bit and the IC should be replaced. If multiple RAM IC's are displayed 'BAD',
- troubleshooting of the system user RAM area will be necessary.
...und wieder einer gerettet 
