alexparr wrote on 2024-01-30, 23:12:

CoffeeOne wrote on 2024-01-30, 23:03:

The setting is actually printed on the mainboard, the setting for 25MHz, 33MHz and 40MHz is documented. So set it to 25MHz and c […]
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alexparr wrote on 2024-01-30, 22:56:

.....
I don't know what jumpers do what. There is no documentation about this motherboard, so I'm kind of just stuck at 66MHz—unless of course I want to break something else.

The setting is actually printed on the mainboard, the setting for 25MHz, 33MHz and 40MHz is documented.
So set it to 25MHz and check what happens.

EDIT: There are 2(!) sections with the writing: 25, 33, 40 MHz. But I cannot read that clearly from these pictures

The ones on the left seem to be for the PCI bus. The ones in the middle are un-labeled. Remind me though, what does "OP" and "CL" mean?
Also for some reason JP13 doesn't have any jumper pins connected.

I guess OP means open, CL means closed.

EDIT: Both are now in the 33MHz setting, is it correct?
If yes, then set both to 25MHz.
Chances that it helps are low, but it is worth a try.
Underclocking is 100% no risk. 😀

Jasin Natael wrote on 2024-01-30, 23:00:

Remove any cards or peripherals that you don't need (sound, drive controllers etc), pare it down to just PSU/MB/CPU/RAM/Video. […]
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Remove any cards or peripherals that you don't need (sound, drive controllers etc), pare it down to just PSU/MB/CPU/RAM/Video.
Reseat everything, including ram, cpu etc.
Check all jumper settings.
Start there.

I tried doing that again, no dice.

CoffeeOne wrote:

I guess OP means open, CL means closed.

Right, that should've been obvious.

Now I have some updates for you all.
I tried removing the two jumpers in an attempt to bring the machine down to 25MHz, and that made no difference; I have since reinstated said jumpers because I do not want to lose those things and I know they worked before. (Before the system died, they were set to correctly register the CPU as a DX2-66.)
One thing that's certain; the reset button still works. I stuck a conductive screwdriver in-between the Reset pins, and the light comes up on the POST card. So that's good I suppose; even if it's just a hardware thing and not a software one.

CoffeeOne wrote on 2024-01-30, 23:03:

MORE EDIT: If I were you, I would get another cpu. Running a DX2-66 without any heatsink for a longer period of time might have killed it.

I'll be getting one with a heatsink once I can afford it, mainly because it's the cheapest route to go. If that doesn't work, then I'll have to ask again if anyone on here (who lives in the US) wants to repair this thing. Soldering is not a skill I have.

One last question about your 25MHz test. You only removed jumpers 14 and 15? And kept the ones for the PCI bus?

Can't make out the mainboard brand/model ....do notice backup battery removed, this isn't one of those boards that won't boot without battery?

CoffeeOne wrote on 2024-01-30, 23:34:

One last question about your 25MHz test. You only removed jumpers 14 and 15? And kept the ones for the PCI bus?

I couldn't for the life of me find the PCI bus jumpers. So no, I just did what I assume is the CPU.

giantclam wrote on 2024-01-30, 23:47:

Can't make out the mainboard brand/model ....do notice backup battery removed, this isn't one of those boards that won't boot without battery?

It's a Jetway motherboard of some kind. It's booted before, so it has nothing to do with there being no battery.

CoffeeOne wrote on 2024-01-30, 23:03:

MORE EDIT: If I were you, I would get another cpu. Running a DX2-66 without any heatsink for a longer period of time might have killed it.

I didnt realize OP was running dx2 without heatsink. Occam's razor, this is very likely answer.
alexparr by "in my hands" you mean you were plying with it and just crashed and never turned back on? Did it ever crash before that? Was it the longest time it was on when it died?

rasz_pl wrote on 2024-01-31, 01:44:

I didnt realize OP was running dx2 without heatsink. Occam's razor, this is very likely answer.
alexparr by "in my hands" you mean you were plying with it and just crashed and never turned back on? Did it ever crash before that? Was it the longest time it was on when it died?

I believe it died when I got my Compact Flash to IDE adapter. I doubt the adapter has anything to do with it. I think the longest the system was on was about 15-30 minutes, and I don't think it was on for that long of a time during that specific day.
I will say though, any time I hit the "Reset" jumper, the video card glitched out; filling up with all kinds of random garbage. It would only go back to normal if I did a hard reset (power off and on). I'm not sure if it was some kind of incompatibility or if it was the video card itself though... as I mentioned though, I got a new card as part of a troubleshooting process (after the system died) so I can't be too sure on that.
All I'm sure of is that a new DX2-66 (with a heatsink this time) is the logical next step, though it's gonna take about a month until I can get it—I have a very, very tight budget for things like this.

alexparr wrote on 2024-01-31, 00:33:

... I couldn't for the life of me find the PCI bus jumpers. ....

What?
Can you make a high res picture of the board?
Then somebody can write down all the jumpers, because nearly all are described on your board. Then we have a manual.
What about the 3 jumpers on the very left, which are all closed?

EDIT: You wrote:
"The ones on the left seem to be for the PCI bus. "
I don't know, if these jumpers are for the PCI bus, I have this information from you. But I could see something with 25, 33, 40MHz.

Your board doesn't seem to have corrosion from battery leakage but it's difficult to tell as the image you posted isn't very hi-res.

I had issues with a 486 board recently, same behaviour you see on your board, no post codes, no beeps etc. My issue turned out to be RAM related. I see your RAM sticks are non-matching. Have tried to remove one and see if it gets to some postcodes with just one stick or the other installed? Just because you received the board like it is doesn't is the original configuration.

Like other have said, running a 66Mhz for some time without a heatsink is not a very good idea. If you don't have a specific heatsink find at least some something chunky metal that can be placed safely on the CPU if you're comfortable doing that.

Jasin Natael wrote on 2024-01-30, 23:00:

Remove any cards or peripherals that you don't need (sound, drive controllers etc), pare it down to just PSU/MB/CPU/RAM/Video. […]
Show full quote

Remove any cards or peripherals that you don't need (sound, drive controllers etc), pare it down to just PSU/MB/CPU/RAM/Video.
Reseat everything, including ram, cpu etc.
Check all jumper settings.
Start there.

In addition to the quoted suggestions, try using the POST card with an ISA port instead. Those Chinese knockoff cards can be a bit flaky when using them on the PCI bus, some of them can even damage the computer. The ISA connection usually works perfectly though.

kaputnik wrote on 2024-01-31, 09:54:

...try using the POST card with an ISA port instead. Those Chinese knockoff cards can be a bit flaky when using them on the PCI bus, some of them can even damage the computer. The ISA connection usually works perfectly though.

I haven't tried that yet as I don't know which direction it's supposed to face.

alexparr wrote on 2024-01-31, 13:46:

kaputnik wrote on 2024-01-31, 09:54:

...try using the POST card with an ISA port instead. Those Chinese knockoff cards can be a bit flaky when using them on the PCI bus, some of them can even damage the computer. The ISA connection usually works perfectly though.

I haven't tried that yet as I don't know which direction it's supposed to face.

There is an arrow icon along the ISA edge (where it says "REAR") that points to the back of the board/case.

rasz_pl wrote on 2024-01-31, 01:44:

I didnt realize OP was running dx2 without heatsink. Occam's razor, this is very likely answer.

Is there any proof that running a DX2-66 without a heatsink can actually kill it?
I would be very surprised if that was the issue.

watson wrote on 2024-01-31, 16:50:

rasz_pl wrote on 2024-01-31, 01:44:

I didnt realize OP was running dx2 without heatsink. Occam's razor, this is very likely answer.

Is there any proof that running a DX2-66 without a heatsink can actually kill it?
I would be very surprised if that was the issue.

Yes, number one they are labeled as such "requires heatsink and fan"
Secondly, I have personally saw it happen. Wasn't me who did it, but I have seen them fail in a surprisingly short amount of time.
Fan isn't necessarily always required, depending on the workload and situation (open air test bench etc) but heatsink is pretty critical.

I tried it in the ISA slot, and we have some information! All but the Reset light is on (due to the reset jumper not being active, obviously) and I'm given the code "07 06". No, there's no beep; and that's after attaching the speaker wires.
If previous footage/photos/memory of mine is anything to go off of, the motherboard has an Award bios, with 06 being reserved and 07 being something like this:
"Verifies CMOS is Working Correctly, Detects Bad Battery"
Which makes sense, given that there's no battery slot soldered into the system. What confuses me is why no battery would suddenly keep the system from booting when it's worked before without one.
The only problem now is I can't solder for crap and still don't exactly know the proper battery that could go in here. Does anyone with a 486 know the type of battery/socket I should get?

https://github.com/wiretap-retro/Not-A-Varta https://github.com/wiretap-retro/Not-A-Varta-CR2032
maybe this https://www.gotek-retro.eu/amiga-cr2032-replacement-varta/ but shipping from EU will be killer. Im sure someone sells something similar in US. maybe https://www.pcbway.com/project/shareproject/V … 2_d81acdb0.html ?

> What confuses me is why no battery would suddenly keep the system from booting when it's worked before without one.

7 does more than battery
"Test CMOS Interface and battery status. Detects bad battery. BE and Chipset Default Initialisation. Program chipset registers with power-on BIOS defaults."
It might be failing initializing chipset, old bad cracked solder joints on big chipset with tons of small legs is a typical failure mode.

Where in the US are you? Maybe someone local can lend a hand or test parts for ya. The fact that your getting codes on the post card now is a good sign.

I have a few of those not-a-varta pcb's and the parts to make em and am in the US.

alexparr wrote on 2024-01-31, 21:56:

[...] I'm given the code "07 06". [...]

According to Award BIOS v6, 07 means: "Clear 8042 interface; Initialize 8042 self test" (Keyboard controller)
Source: https://uxd.zendesk.com/hc/en-us/articles/360 … OST-Error-Codes

Have you tried reseating this chip?

alexparr wrote on 2024-01-31, 21:56:

I tried it in the ISA slot, and we have some information! All but the Reset light is on (due to the reset jumper not being activ […]
Show full quote

I tried it in the ISA slot, and we have some information! All but the Reset light is on (due to the reset jumper not being active, obviously) and I'm given the code "07 06". No, there's no beep; and that's after attaching the speaker wires.
If previous footage/photos/memory of mine is anything to go off of, the motherboard has an Award bios, with 06 being reserved and 07 being something like this:
"Verifies CMOS is Working Correctly, Detects Bad Battery"
Which makes sense, given that there's no battery slot soldered into the system. What confuses me is why no battery would suddenly keep the system from booting when it's worked before without one.
The only problem now is I can't solder for crap and still don't exactly know the proper battery that could go in here. Does anyone with a 486 know the type of battery/socket I should get?

The display shows two codes, the current and the previous one. Your board fails to initialize the keyboard controller (07).

Got a Pentium board halting on POST code 07. In my case, the KB controller (also a VT82C42N btw) really is busted and needs to be replaced once I find one at a reasonable price, but noticed there are plenty of connections between the BIOS chip and the KB controller when troubleshooting it. It's a longshot since at least parts of the BIOS loads and executes, but try pulling and reseating the BIOS EPROM a couple of times.

Also, adding a CMOS battery certainly can't hurt.

The reset line is supposed to be low during boot, the unlit reset LED is in it's order.

I don't have experience with these POST cards so I maybe have a stupid question...is the last displayed code (07) the one trying to be tested (the card displays it at the beginning of the test), or the last one successfully tested (the card displays it at the end of the test)? I wonder if the failing code is 07 or actually the next one failing, 08. Again, I have no experience with these cards and I'm just asking.