How good is the cmos battery?

Caluser2000 wrote:

How good is the cmos battery?

Good. I replaced it with a 3 cell AAA Eneloop set. Charging and standing voltages through the board seem to be ideal.

Bios settings have probably been reverted to whatever the defaults are though, of course. Board layout and jumpers seem to be stock defaults. I guess this board was mostly unused that someone had as a backup board and never got around to using or needing.

The expansion cache is fully populated with 256K and the board is setup for an installed DX2-66. I have a DX4-100 to upgrade to at some point, but haven't done so yet.

Let me know if a picture of the board or anything else might help.

Is there a Bios erase jumper? If not you can pull the bios chip and short it on some tin foil.

page 44 of the manual shows the CMOS clear jumper (J48). Are you sure the ram is good ? Have seen old boards report bad video card when the ram was the real issue. Also if trying an ISA card put it in one of the ISA/VLB slots or the ISA nearest the PSU power connectors.

Caluser2000 wrote:

Is there a Bios erase jumper? If not you can pull the bios chip and short it on some tin foil.

Yeah, now that you mention it, I did do this previously as well – using the clear cmos jumper that is. It was a while ago though.

Horun wrote:

page 44 of the manual shows the CMOS clear jumper (J48). Are you sure the ram is good ? Have seen old boards report bad video card when the ram was the real issue. Also if trying an ISA card put it in one of the ISA/VLB slots or the ISA nearest the PSU power connectors.

Yeah, I've tried the video cards in all available slots they can go in, not the VLB in the regular ISA ones though.

Tried the 8MB it came with from the seller as well as others, all the way up to the max 128MB. With the different capacities, the secondary boot tones after the error code take longer with the higher capacities, I think because it is going through and testing it.

The power supply is an older used one of mine that isn't that great. You think there's a good chance that might be causing the issue for some reason? Everything else seems to be working fine on the board when connected, at least as far as I can tell, of course.

Just tried changed out the RAM and resetting the cmos again, by the way. No luck; same error and behavior.

Could be a supply issue. Do you have a digital voltmeter ? If so check the volts while it is connected to the motherboard and turned on. Should get the 5v 12v -5v and -12 v within +/- 0.2 volts on the main power connector. Here is the standard AT PSU pinout:
http://www.minuszerodegrees.net/5150_5160/mis … of_5170_psu.jpg

More importantly, check power supply ripple at load. A multimeter may show a good voltage (avg measurement) but if you have high AC ripple feeding it, you'll get failed boots, crashes, errors, etc. It is best checked with an oscilloscope, but a Fluke with TrueRMS can provide a halfway decent reading of ripple as well.

Probably not all that much load on or from the board, but I'll take off the drives in case that might help or change results. Just a regular, decent but not great DMM. 'Fraid my wife hasn't let me get a Fluke DMM just yet. 😊

I'll report back as best I can later today or tomorrow. Perhaps worth noting that I get the same error as well without any video card attached, but I'm not sure if that's just the MB telling me there's no working video card for whatever reason either way.

Thanks.

Horun wrote:

Could be a supply issue. Do you have a digital voltmeter ? If so check the volts while it is connected to the motherboard and turned on. Should get the 5v 12v -5v and -12 v within +/- 0.2 volts on the main power connector. Here is the standard AT PSU pinout:
http://www.minuszerodegrees.net/5150_5160/mis … of_5170_psu.jpg

OK, seems mostly in spec, though the -12V was -12.4 something – the rest were well within the 0.2V tolerance mentioned. And this was with the drives (HDD, floppy, and CD) disconnected. Same issue though, unfortunately.

Might try taking the bios chip out and shorting it too, just in case.

Any other ideas or suggestions? Or maybe for some reason the -12.4V could be the issue?

Thanks a lot for your guys' help so far, by the way. Really hoping I can get this sorted and working, as the board seems quite nice otherwise.

Cheers.

At this point I'd try to reprogram the BIOS EEPROM if you have the BIOS image.
You can use an external EEPROM flasher, use the procedure described in the manual starting with page 107 (this shouldn't require a working graphics card) or use another mainboard to hotflash the EEPROM.

OK, I was able to track down a copy of the bios firmware and it looks like I can flash it from a floppy as mentioned, so I'll give that a try at some point and see if maybe that'll work.

Thanks.