crvs wrote on 2020-08-03, 20:08:
mkarcher wrote on 2020-08-03, 07:30:
In that case, the issue sounds like broken traces or solder connections between the EMU8k chip and the DRAM sockets. You could try to buzz out that all relevant pins at the memory sockets (parity-related pins are not relevant) are indeed connected to the synthesizer chip.
Yes I know RAM modules should be identical, tried only 2x1, 2x4 and 2x16 mb combinations, with all SIMs good and tested.
Thank you for idea, missing contact looks plausible, could you please give me a hint which connections to check? I'm not that good in the electronics, and didn't find EMU data sheet or AWE schematics over the web 🙁
The AWE32 should indeed work with all of your combinations, although I never tested 2x16 because I don't have this kind of modules. As I'm currently on vacation, I can't check what connections to check, but it is very likely that all address and data pins, as well as /WE, /RAS and /CAS are directly connected to the EMU8K chip. As I own a quick-reacting continuity tester, the way I would test my card is putting one probe at a SIMM pin (you can omit the power pins 1, 9, 22, 30, as well as the parity-related pins 26,28,29) and gently brushing over the EMU8K pins with the other probe. If the connection is working, you should hear a short beep.
Typically, connections are grouped (like all data pins next to each other), possibly interrupted by ground and power pins, so if one data pin is missing, the interrupted trace should be obvious just from the neighbouring connection - and even if not, just knowing which RAM pin does not connect to any AWE32 pin is a great help because it points to a specific trace that you can inspect more closely.
As the AWE32 has 16-bit memory access, the address and control lines of both SIMM sockets should be paralleled (a very simple thing you can quick-check for broken traces between the sockets), whereas the data lines should be separate for a total of 16 individual data lines. If you happen to have an ESR meter (to check capacitors), you could also check ESR between +5V and GND at the SIMM sockets. High values (>2 Ohm) point to bad decoupling caps near the socket. As I don't have my SB32 at hand, I can't give you a reference value from my card.
Don't disregard the software hint, though. While I never had issues with my SB32 in a Pentium 133 machine, it is possible that DIAGNOSE indeed fails on faster machines.