Minutemanqvs wrote on 2024-02-01, 11:46:

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.

According to the manual, it's "real time" iirc. I've always assumed that means it's the one currently being tested, and that it's displayed until the test successfully finishes.

kaputnik wrote on 2024-02-01, 12:11:

Minutemanqvs wrote on 2024-02-01, 11:46:

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.

According to the manual, it's "real time" iirc. I've always assumed that means it's the one currently being tested, and that it's displayed until the test successfully finishes.

Recently I was reading disassembly of an old AMI BIOS and it was sending post codes before performing associated test. Anyway it's better to think about the last code, and the next one.

FOr 4.5 non-PNP code 07 says:

Test CMOS Interface and battery status. Detects bad battery. BE and Chipset Default Initialisation. Program chipset registers with power-on BIOS defaults.

This means that POST reads values from CMOS memory located in Chipset, tests for values associated with dead battery, and if detects that, fills up the CMOS memory with hard-coded default values. So, if it hangs during this operation, it seems that something wrong either with low battery detection (maybe erratic random data are in the CMOS and manual CMOS clear is needed), or with writing/reading to/from CMOS (bad tracks, unsoldered leg on the chipset, bad line driver, short in one of expansion card slots, memory, SIMM, something like that, preventing CPU/chipset from correct addressing I/O ports 70/71h.)

Also I wouldn't exclude a possibility of corrupted BIOS image, however it's very unlikely for UV-eraseable EPROM and more specific for PROM and FLASH. (Yes I had several failed VGA cards and motherboards due to FLASH, corrupted after 20-30 years of non-use. I can't say why PROM fails but I had couple of Trident VGA cards with failed VGA BIOS). Nerevtheless, BIOS checksum test comes later, at 0F, so at this point we have to trust to BIOS.

What exactly is the model of this board? I was not able to find it on TRW.
In any case, it's a nice VIP board, definitely worth saving.

we tried identifying it earlier and failed This motherboard—can someone identify it?
its related to https://theretroweb.com/motherboards/s/jetway-j-403tg-v1.0
mkarcher: "also sold under the Edom/WinTech and Lucky Star https://theretroweb.com/motherboards/s/edom-w … ech-mv035-rev.c"
also BEK-tronic Re: The Retro Web project - a better stason.org/TH99 alternative

kaputnik wrote on 2024-02-01, 09:23:

The display shows two codes, the current and the previous one. Your board fails to initialize the keyboard controller (07). […]
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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 […]
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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 think this is necessarily true. Seeing an 07 as the last code can mean that there was a problem at 07 or, it might have successfully performed the POST for 07 but it can't make it to the next code, which will then never be displayed.

pan069 wrote on 2024-02-01, 22:06:

I don't think this is necessarily true. Seeing an 07 as the last code can mean that there was a problem at 07 or, it might have successfully performed the POST for 07 but it can't make it to the next code, which will then never be displayed.

not so successfully if it made it crash in under 10 CPU instructions 😀 Imagine setting ram to 0 waitstates, you could argue BIOS successfully set it to 0ws but then computer crashed for some weird reason before reaching next step 😉

A person on this board contacted me a while ago who could fix the motherboard (I verified him; they seem legit) and I just got the motherboard shipped out yesterday. I'll keep you all updated on another thread when I get the motherboard back.

Why in another thread, and why the secrecy who he is? We should celebrate those kinds of people!

rasz_pl wrote on 2024-02-08, 03:02:

Why in another thread, and why the secrecy who he is? We should celebrate those kinds of people!

It'll be in another thread because otherwise it might derail the topic of this one. I'll at the very least post one update here when I get the motherboard.
As for the "mysterious repairman", he never posted anything in this thread specifically, and I didn't see any posts on the board about what he does, so I just assumed that he wanted to keep what he does somewhat of a secret. Which is understandable in his regard; I believe he wants to keep his business relatively small, so I don't think he wants too many people asking to repair their motherboards just yet.
That being said, if you're the guy; feel free to show yourself if this isn't the case.

rasz_pl wrote on 2024-02-01, 23:37:

pan069 wrote on 2024-02-01, 22:06:

I don't think this is necessarily true. Seeing an 07 as the last code can mean that there was a problem at 07 or, it might have successfully performed the POST for 07 but it can't make it to the next code, which will then never be displayed.

not so successfully if it made it crash in under 10 CPU instructions 😀 Imagine setting ram to 0 waitstates, you could argue BIOS successfully set it to 0ws but then computer crashed for some weird reason before reaching next step 😉

It would be funny when just the cpu is dead. But there is still some life in the cpu, so maybe something else died.
It is amazing, that the whole setup, but also the diagnosis with the post card was done without a heatsink on the cpu.

CoffeeOne wrote on 2024-02-09, 16:58:

It is amazing, that the whole setup, but also the diagnosis with the post card was done without a heatsink on the cpu.

I believe companies thought that the ceramic that 486 CPUs have basically acts as its' own heatsink; that's likely why a lot of 486 setups from back then don't have a heatsink or fan on the CPU.

alexparr wrote on 2024-02-09, 17:44:

CoffeeOne wrote on 2024-02-09, 16:58:

It is amazing, that the whole setup, but also the diagnosis with the post card was done without a heatsink on the cpu.

I believe companies thought that the ceramic that 486 CPUs have basically acts as its' own heatsink; that's likely why a lot of 486 setups from back then don't have a heatsink or fan on the CPU.

Nope.
The classical i486 DX 33MHz was designed to run without any heatsink. Still Dell used large passive heatsinks with their Optiplex computers.
On 486 with 50 MHz, it changed: Normally always heatsinks and fans were used. But still a passive heatsink with some minimal air flow in the case is enough.
Even more the case for DX2-66 CPUs. They need a passive heatsink. Just look at the intel DX2ODPR 66. No fan, but large enough heatsink.

386, 486, and even early Pentiums may take minutes to heat up to 50+degs. On high work load they may take 10 seconds.

The 07 code according to one Award Bios table meant Keyboard BIOS, I don't know why you wouldn't just reseat it or try another KB BIOS.

Its not the battery is it? I'm sure that you know better, I just didn't see one connected. I see its been mentioned before. Ya no battery on some boards is no post. It could of been just a fluke that it posted before.