The buzzer on that POST card need to be connected to mobo SPEAKER output. That's what that 2-pin connector next to the buzzer is for. You won't get any beeps otherwise.
Some of these 486 mobos are really picky about RAM sticks. Do try the other bank, and possibly other RAM sticks if you have them.

If you have a digital voltmeter check the voltage on the screw (or center lead) of Q4 to ground, it should be 3.3v. If not then it is not regulating voltage properly. Try a 5v 486 and see what happens.

Deunan wrote on 2021-04-17, 22:55:

The buzzer on that POST card need to be connected to mobo SPEAKER output. That's what that 2-pin connector next to the buzzer is for. You won't get any beeps otherwise.
Some of these 486 mobos are really picky about RAM sticks. Do try the other bank, and possibly other RAM sticks if you have them.

Oh alright. I had my speaker connected when testing so it still isn’t beeping.
I’ve tried 3 different sets of ram sticks I have, and in multiple banks, doesn’t seem to make a difference though.

Horun wrote on 2021-04-18, 00:40:

If you have a digital voltmeter check the voltage on the screw (or center lead) of Q4 to ground, it should be 3.3v. If not then it is not regulating voltage properly. Try a 5v 486 and see what happens.

I have a multimeter, sorry what do you mean by Q4?

figbash wrote on 2021-04-18, 02:23:

Horun wrote on 2021-04-18, 00:40:

If you have a digital voltmeter check the voltage on the screw (or center lead) of Q4 to ground, it should be 3.3v. If not then it is not regulating voltage properly. Try a 5v 486 and see what happens.

I have a multimeter, sorry what do you mean by Q4?

He means the lone transistor at the edge of the motherboard, directly south (in the orientation of your photo) of the right-most VLB slot. It’s marked Q4 in the silkscreen.

Thanks! Ok I tested the voltage on Q4 and it’s nowhere near 3.3v, it’s .6 and 1.2. What would that mean?

A bit offtopic, but what is that program you've used to see the jumper settings ?

Deksor wrote on 2021-04-18, 23:58:

A bit offtopic, but what is that program you've used to see the jumper settings ?

It’s something EFA made for their boards called goefa

figbash wrote on 2021-04-18, 23:43:

Thanks! Ok I tested the voltage on Q4 and it’s nowhere near 3.3v, it’s .6 and 1.2. What would that mean?

Sounds like that transistor has failed, which means the CPU won’t be getting the right (or stable) core voltage.

Replace that transistor and you may find the board comes back to life!

Recently had to do the same to my M919, replaced the CPU core voltage power transistor and it started working properly.

http://www.win3x.org/uh19/motherboard/show/2057
added your photo to the page. It looks like we still miss the bios, if you got this board working, would you please make a dump for us?

paradigital wrote on 2021-04-19, 04:33:

Sounds like that transistor has failed, which means the CPU won’t be getting the right (or stable) core voltage. […]
Show full quote

figbash wrote on 2021-04-18, 23:43:

Thanks! Ok I tested the voltage on Q4 and it’s nowhere near 3.3v, it’s .6 and 1.2. What would that mean?

Sounds like that transistor has failed, which means the CPU won’t be getting the right (or stable) core voltage.

Replace that transistor and you may find the board comes back to life!

Recently had to do the same to my M919, replaced the CPU core voltage power transistor and it started working properly.

Shouldn’t the input pin and ground of the transistor show 5V even if it’s bad? That’s what is showing 1.2, and output .6. Just want to make sure that’s what I should be replacing 😀

figbash wrote on 2021-04-19, 15:22:

Shouldn’t the input pin and ground of the transistor show 5V even if it’s bad? That’s what is showing 1.2, and output .6. Just want to make sure that’s what I should be replacing 😀

input yes (possibly), ground... no 😀 ground should definitely read 0 if it's actually ground.

edit: Unless that shiny plane to which the transistor is attached has continuity to ground, I'm just going to assume that its just being used for cooling, not grounding or power.

weedeewee wrote on 2021-04-19, 15:45:

figbash wrote on 2021-04-19, 15:22:

Shouldn’t the input pin and ground of the transistor show 5V even if it’s bad? That’s what is showing 1.2, and output .6. Just want to make sure that’s what I should be replacing 😀

input yes (possibly), ground... no 😀 ground should definitely read 0 if it's actually ground.

I meant testing with the positive probe to input/collector transistor pin and the negative probe to ground 😀

evasive wrote on 2021-04-19, 06:21:

http://www.win3x.org/uh19/motherboard/show/2057
added your photo to the page. It looks like we still miss the bios, if you got this board working, would you please make a dump for us?

This is the BIOS for it
http://web.archive.org/web/19970429031842/htt … rd/hl3g_105.exe
And here is the jumper setting program
http://web.archive.org/web/19970429031854/htt … board/goefa.exe

figbash wrote on 2021-04-19, 15:54:

weedeewee wrote on 2021-04-19, 15:45:

figbash wrote on 2021-04-19, 15:22:

Shouldn’t the input pin and ground of the transistor show 5V even if it’s bad? That’s what is showing 1.2, and output .6. Just want to make sure that’s what I should be replacing 😀

input yes (possibly), ground... no 😀 ground should definitely read 0 if it's actually ground.

I meant testing with the positive probe to input/collector transistor pin and the negative probe to ground 😀

Which "ground" did you use?, also there's three pins so you should have 3 values.
as I added to my previous comment, is that shiny plane to which the transistor is coupled ground or just there for cooling ? ie does it have 0 ohm to power supply connector ground ?
I think it's just there for cooling.

weedeewee wrote on 2021-04-19, 16:10:

Which "ground" did you use?, also there's three pins so you should have 3 values. as I added to my previous comment, is that shi […]
Show full quote

figbash wrote on 2021-04-19, 15:54:

weedeewee wrote on 2021-04-19, 15:45:

input yes (possibly), ground... no 😀 ground should definitely read 0 if it's actually ground.

I meant testing with the positive probe to input/collector transistor pin and the negative probe to ground 😀

Which "ground" did you use?, also there's three pins so you should have 3 values.
as I added to my previous comment, is that shiny plane to which the transistor is coupled ground or just there for cooling ? ie does it have 0 ohm to power supply connector ground ?
I think it's just there for cooling.

I'm embarrassed to admit I completely misread an earlier comment and thought the center pin was ground, I see now this is not how transistors work. I have retested using the ground around a screw hole and from right to left the readings are: 4.4, 5, 3.8

I'm able to get it down to 3.6 (but not 3.3) by messing with the voltage setting jumpers with the CPU removed, though it still doesn't post and the 3.8 is the official jumper layout.

I don't know the specs of the part on your board - such as what the tolerances are, but it can be quite common for the output voltage to be higher than expected when you have no load connected.

That said, we're talking about 486 technology here - I would expect +3.6v to be within the tolerances expected; it's not like modern processors and their ultra narrow voltage ranges.

do you have a jumper on JP3 1-2 set for normal cmos mode ?

figbash wrote on 2021-04-19, 18:29:

I'm able to get it down to 3.6 (but not 3.3) by messing with the voltage setting jumpers with the CPU removed, though it still doesn't post and the 3.8 is the official jumper layout.

I think the voltage is OK, it's not uncommon to have it a bit higher to compensate for drop with load and/or stability. So long it's not over 4V the CPU will be fine. And it's working at least well enough to show some codes (and reacts to missing memory with C1 error, that also seems correct).

Try lower CPU clock (20/25 MHz) to see if that will make it go any further. Go over all the mobo jumpers (I know, tons of them), especially those that you didn't touch or are not sure what they do - and try to establish what each of them do and if it's set correctly. Perhaps one is missing or something.

And again, these mobos are really quirky about RAM. Most will not tolerate EDO sticks, only FPM ones, and even that is no guarantee. You only need one 72-pin RAM stick to get a 486 mobo to work. See if you have any 4MB sticks, I don't think any of those were EDO, too old for that.