VOGONS


First post, by doctoren

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Hi,

I recently got my hands on a second PVI-486SP3 board. Both this and my existing one are 1.22 revisions and besides different south bridge revisions seems to be identical.
However, I can't get the new board to post. Initially I didn't get any error beeps but that was due to a non-working pc speaker.
The board came with RAM and a AMD DX4 but I have also tried using CPU and RAM from my working setup and aligned all jumpers to no success.
After replacing the beeper I get continuous high beeps. There is no sticker on the Winbond chip on the new board but I can only assume that this also uses an Award bios. The only pattern that seems to match is the CPU overheating error. I found that a little implausible as the CPU both has a fan and works flawlessly with my old board.

I only get beeper errors when a cpu is socketed. Nothing if CPU, RAM and graphics are removed or just RAM and graphics are present.

Does anyone have an idea whether this may be caused by a defective sensor on the motherboard or whether this error might be something else entirely? Would it be worth trying to swap the bios chip as well?

Reply 3 of 7, by kixs

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If you've set the voltage to 5V for your DX/2-66 and it didn't work. Then VRM isn't a problem.

When VRM fails the 3.3/4.0V voltages don't work. You just have to replace the VRM.

My Amibay: SALE | BUY - Updated on 2020-05-25

Reply 5 of 7, by debs3759

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I've been wondering how to set for 5V on that board. I wondered whether it just needed the voltage jumpers leaving open, as everything I have read indicates it can run any 486, but have never seen 5V settings mentioned.

Reply 6 of 7, by Horun

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Very odd that even going back thru Asus.com on Archive.org does not explain jumpers for using a standard 5v DX or DX2 very well except in table form.
Did go thru a bunch of web pages/archives and Am guessing that when set as a Intel 80486SX, 80486DX, 80486DX2 or 80487SX that it bypasses the VRM and runs at 5v.
(all are typically Intel 5v, all same jumpers except JP22 <pushes to multiplier> AND JP23 setting for if MatchCo present) .
Of course I could be wrong but that is my best guess. If you use an Intel DX or DX2 the settings are quite clear on a quick inspection...
http://web.archive.org/web/19981206001158/htt … 486sp3-tech.asp
http://www.win3x.org/uh19/public/motherboard/ … anual/32715.pdf

Hate posting a reply and have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. 🤣 Second computer a 286 12Mhz with real IDE drive ! After that came 386, 486, Pentium, P.Pro and everything after....

Reply 7 of 7, by doctoren

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For all intents and purposes I believe the SX955 should cover the 5v case. The only other compatible CPUs I have on hand are DX4-100 (SK096) and 2 Am486 DX4-100 (NV8T) which are all 3v CPUs. I have tries all 3 variants with no success. I think I can rule out me misunderstanding the jumper settings as I have had no issues with configuring the CPUs on the old board 😁 Also, from past experience this usually wouldn't have prevented posting.

I think I can get my hands on other compatible CPUs, a plain 80486DX among them. I suspect that JP22 should be left all open in this case or maybe it doesn't matter as the CPU only has 1x multiplier?

Also, the error codes annoys me. The award error codes I have found are very simple and what I believe what I'm hearing is the CPU overheating which seems like something you might encounter later when CPU fan headers are present on the board but not connected. Alternatively, it could be a memory issue, since this is also continuous beeping but the RAM modules themselves should be fine. I will go through the entire flow again but I find it a bit odd that I didn't get any errors when having everything unplugged. I would have expected to get something like memory, video or a CPU missing error?