Quoted from tripplett:I’ve replaced a Terminator 2’s Mosel 6264 ram with a Ramtron 1608 nvram and it’s not booting. My first nvram and battery removal. Booted and D19 and D21 come on solid and stay on solid. I here a hum from the sound and the display shows nothing. Since led D19 should go out after 1 second I’m wondering if something is up with the blanking signal.
Details:
I cut the 6264 off by snipping each leg off close to the chip then carefully removing each pin one by one. I inspected the board closely for damaged pads and traces and even toned a few pins against the schematic. All were ok. [quoted image]
I then soldered on the socket, again toned many (but not all) of the pins that looked suspect. All were again ok. [quoted image]
Placed the Ramtronics, reinstalled the board, and no boot. D19 and 20 stay on solid. [quoted image]
Verified 4.75v at the nvram so shouldn’t be resetting. Tried one of those no reset boards that pulls 5v from the 12v feed and got 4.88v at the nvram. No change - I didn’t expect one really.
Verified via PinWiki that my jumpers and resistors for the ram and memory are right. W3 out, R93 in. W1 in, W2 out. Somewhere I had seen a boot up sequence but can’t find it right now. I pulled the board and will verify every pin vs schematics but I’m not sure what else to check. Did I get a bad nvram or something? Did I miss a step?
Do you have another RAM chip to try? Either a 6264 SRAM or another NVRAM chip? There are fake RAMTRON chips out there. Did you buy it from a reputable source or off ebay? I would try another chip.
Also, the EPROM is uncovered. You should always keep that window covered. Too much exposure to UV will start to erase it. If a bit gets erased or corrupt it won't run. If you have access to an EPROM programmer you could verify the contents are still ok.
Cleveland, OH
