Sadly, I have no advice for you, but that is an excellent first post, very detailed and thorough.

>all I can get from the post analyzer card is CF then EF.

neither of those is valid. Can you scroll further back on the POST card?

https://blog.theretroweb.com/2024/01/20/award … ost-codes-list/

According to those lists C and E are at the end of the POST, not the start. I had a corrupted bios recently on a TX chipset motherboard, it was a bad bios chip but reflashing fixed it.
Try flashing another eprom if You have an eprom burner. Other than that, try another cpu if You have one.

Some more information on what You are connecting to it may help.

Imperious wrote on 2024-04-23, 03:45:

https://blog.theretroweb.com/2024/01/20/award … ost-codes-list/

According to those lists C and E are at the end of the POST, not the start.

someone either corrupter that table or sorted it alphabetically 😀 C codes are at the very start

You are correct. Check more sources of information I guess.
EF is at the end though, setup pages, whatever that is.

Anyway, more information on the hardware will be helpful.

As far as I can tell, the only 2 post codes that show up are the CF and the ef. I do see odd behavior when I put the post card into the pci slot. It seems like the cf/ef codes flash back and forth. The isa slot just stays solid and when I scroll back through the codes, only the 2 are in the stack. I will attach a photo of the post card in the isa slot on case some of the other lights are helpful to anyone.

The bios suggestion was high on my list of concerns. I used a completely new eeprom and I burned from the only available image on the Retro web. Doing a binary compare between the bios that came on the board and the one from the Retro web showed some differences, but not many.

I truly appreciate the comments and suggestions. Please let me know if you can think of anything else.

If we have post codes we know that the cpu is running code and that both the north bridge and the south bridge are working. The third step in those test sequences in the post codes link is the keyboard controller. I would focus my attention there. Is there any cut trace, solder blob, corrosion, etc around that area? Is the keyboard controller unusually hot?

I disassembled your bios and its normal award, post codes start from C0.
hmm do you have another cpu? also if you have remove TAG ram and cache from cache slot. From C0 to CF is a lot of bits and instruction for something like broken tracks distorting data
Did you scroll on a post card all the way to "END-"?

Hello all,
First off, again, everyone has been very helpful.

The board is very very clean. No scratches or corrosion. I very carefully looked on top and bottom of the board and didn't see anything amiss.

I scrolled "up" through the post codes and I see EF, then CF, then --End.

I was pretty sure my P90 was well tested, but I did change it out for a P133 and set the jumpers for that. The 133 does give me a different clock (66 instead of 60) in case something is off with the clock generation. There could still be more here, but I'm pretty sure there is a clock as my post analyzer is showing clock detected.

I removed the cache tag chip, and I don't have a coast ram installed, but I believe there is 256K onboard of L2. I did think something might be wrong in the RAM/cache early on, but nothing I tried lead me anywhere. I have not changed any standard logic ICs near the RAM, which I can try if anyone thinks that might be helpful.

I can remove the keyboard controller, but I'm a little too busy until the weekend to try that. The IC is not even slightly warm to the touch. I do have a donor board with the same keyboard controller chip, but I kinda wish to get a socket if I'm going to desolder an IC. If this is a direction to try, I will order the socket now and try to swap it out this weekend.

Thank you very much!

Looking at the disassembly of bios I dont see the way for it to start with CF code.
Since you have a programmer can you try those Deunan bioses Re: Problem with DTK PEM-4036YB (PEM-0036Y), no post ? those will test if path between CPU and POST card is working correctly

Great call on trying the Deunan bioses!

The POST1a had the same exact results as the real correct bios. EF and CF. The POST2 had no post codes at all. No bios chip installed also results in no post codes. I returned to POST1A and the EF and CF returned.

My eeprom is 128kb (I don't have any 64kb spare eeproms), so I had to pad the 64kb files with an additional 64k of 1's. I'm attaching here the actual files I burned just in case I messed anything up with the padding.

My sockets for replacing the kbc should arrive before the weekend, so I will give that a try this weekend.

Thanks again, all

This is very weird, no matter what cpu tries to output you end up with same garbage on post card? :0
Deunans post1a should continuously output 55AA

1FFF0                 mov     al, 55h
2FFF2                 out     80h, al         ; manufacture's diagnostic checkpoint
3FFF4                 jmp     short $+2
4FFF6                 jmp     short $+2
5FFF8                 mov     al, 0AAh
6FFFA                 out     80h, al         ; manufacture's diagnostic checkpoint
7FFFC                 jmp     short $+2
8FFFE                 jmp     short loc_FFF0

Yes, I have verified that the post1a produces the same output as the real bios. No bios or the post2 results in no post codes.

Is there anything else that could cause the cpu to execute some other code? Does the kbc execute its own code? Could anything else put a command onto the bus?

Not really, nothing comes to mind 🙁
post2 should output something, it does exactly two writes to diagnostic card so that tells us somehow on your board you need to bruteforce ISA bus to get anything? or that its something else going wrong and those bad post codes are how your POST Card reacts. Hmmm, maybe bad ISA clock would do it? Either very slow or very fast?

I did finish trying the new KBC. Unfortunately, it is still just EF/CF. I did see them bounce a little like they do when I plug it into PCI slot, but only immediately on start up.

If I were to try the ISA clock, where it the best place for me to measure that with my oscilloscope? I finally have my first scope, so I'm not great using it, but I will definitely give it a shot.

Thank you!

Maxvintage871 wrote on 2024-04-27, 23:14:

I did finish trying the new KBC. Unfortunately, it is still just EF/CF. I did see them bounce a little like they do when I plug it into PCI slot, but only immediately on start up.

If I were to try the ISA clock, where it the best place for me to measure that with my oscilloscope? I finally have my first scope, so I'm not great using it, but I will definitely give it a shot.

Thank you!

This is the keyboard controller datasheet, same for all as they are compatible with the original P8042 made by Intel:
https://pdf1.alldatasheet.com/datasheet-pdf/v … EK/HT6542B.html

Check ISA to chipset following this datasheet:
https://theretroweb.com/chipset/documentation … 77539962805.pdf

ISA between them as they are all in parallel:
https://en.wikipedia.org/wiki/Industry_Standard_Architecture
use picture

If you have an oscilloscpe check every oscillator, and the frequency generator (the 48C60-406G). You should find, 33 MHz one for each PCI, FSB (50-60-66 as per selection).
Socket 7 fsb is at pin AK18 (https://www.arl.wustl.edu/projects/archive/gi … X_Datasheet.pdf

Maxvintage871 wrote on 2024-04-22, 23:15:

I have a Triton I motherboard https://theretroweb.com/motherboards/s/epox-pronix-ep-p55-tf ... That is stuck really early in POS […]
Show full quote

I have a Triton I motherboard
https://theretroweb.com/motherboards/s/epox-pronix-ep-p55-tf
... That is stuck really early in POST. The board is running an Award BIOS and all I can get from the post analyzer card is CF then EF.

The button cell battery is above 3 volts. There are no beep codes. There is no change to the POST codes even without ram, video card, keyboard.

I have changed out the cpu to a known working one. I have programmed a new bios from the Retroweb but no differences (the code on the eeprom that came with the board wasn't much different from what I found on the Retro web).

I have measured the voltages on vcc2 and vcc3 on the socket 7 and both look good at 3.6 volts.

Do you have any suggestions on the next thing I should investigate? I can't even find a CF post code for award bios so I'm really not sure where this is stuck. Maybe memory page setup but ram doesn't make any differences.

Thank you very much

Try a different kind of cpu or a different multiplier.

I assume you are trying a p54 pentium, try a overdrive or a k5 or a 233anr k6

If you have vcc2 try a mmx at 2.8v

I’ve seen some boards be cranky about p54 but like p55

Also try different ram.

Sphere478 wrote on 2024-04-28, 01:05:

Try a different kind of cpu or a different multiplier.

why multiplier? multipliers are cpu internal. nevertheless OP tried 90 and 133

Sphere478 wrote on 2024-04-28, 01:05:

Also try different ram.

its way before ram gets touched, problem is without any ram

rasz_pl wrote on 2024-04-28, 02:58:

why multiplier? multipliers are cpu internal. nevertheless OP tried 90 and 133 […]
Show full quote

Sphere478 wrote on 2024-04-28, 01:05:

Try a different kind of cpu or a different multiplier.

why multiplier? multipliers are cpu internal. nevertheless OP tried 90 and 133

Sphere478 wrote on 2024-04-28, 01:05:

Also try different ram.

its way before ram gets touched, problem is without any ram

I’ve seen it fix it, idk why. It’s weird.