First post, by Nexxen
Hello lovely people,
I was gifted an unknown ISA Card from UMC, I'll go with the gpu model name, UMC UM85C405AF.
http://www.vgamuseum.info/index.php/news/item … -umc-um85c405af
I had some artifacting, decided to clean contacts. There were cracked solder joints on vram and size selector.
I removed all socketed chips and used some deox spray. After that no boot, no beeps either, detected but not working.
I found the problem, the chip UM9502 was mounted backwards. 🙁
Probably I mistook the dot for the indent of pin1. [head banging the wall]
Couldn't locate the datasheet but looking at other cards there are alternatives.
1. ICS2494N ----> probably my only choice
2. PALCE 16V8H-15PC/4 (but this is a programmable and good luck finding one + programmer + program diagram)
BIOS I can't read or write as I can't figure out what it is, UM23C256A-4227. Tried all same size with TL886 and always has a pin1 error.
Basically I'm looking for a substitute of the UM9502 and the an EEPROM to check if the bios is toast (guess not though).
Thanks for any input.
PC#1 Pentium 233 MMX - 98SE
PC#2 PIII-1Ghz - 98SE/W2K