VOGONS


First post, by son_dh

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I bought a socket 7 motherboard (VT586VXC) for cheap, with a warning from the vendor that was he just sell it as it is, nothing guarantee that anything works.

The motherboard arrived, clean and neat, with 2 EDO ram sticks (I think 8 or 16 mb each), and a Pentium SL23X. Plugged the PSU in, turned it on, and nothing.

The CPU was hot on touch, but there was no beeping sound from the motherboard (I used an internal speaker from one of the modern motherboards). Here are the things that I have tried:

  • Cleaning the EDO ram sticks and reseat them to different slots
  • Using my spare SDRAM sticks, from 32 MB to 256 MB (I did not mix EDO + SDRAM)
  • Looking up a rare scan of the motherboard's manual, but it was VT586VXB model, not _C like mine. Didn't help me much
  • Getting a PCI analyser card (didn't come with a manual), got C6C6 on the LCD of the board consistently, with any kind of RAM.

On visual inspection my board seems fine. I have a few photos attached below, for me I didn't see anything wrong with any capacitor yet.

A relative of mine is an engineer (and an amateur electrical engineer), he has an oscilloscope and such. I could ask him to use his tools to check the motherboard, but I need to nail down a few pointers for him to start, since he's not really fluent in computer electrical engineer stuff. So any advise could help us start!

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Reply 2 of 19, by jmetal88

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You could also do a microscopic inspection and look for broken or shorted traces. I've had issues before where something scraped against a board and caused either traces or IC legs to short, rendering the board unusable until the displaced metal was removed.

Reply 3 of 19, by cyclone3d

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You're using a stick of RAM underneath the bard as a support? That is just asking to short something out.

Do you have a CR2032 battery to install in the battery holder for the CMOS? Some boards will not POST without a battery or with a dead battery.

Are the jumpers set properly? Have you tried reseating the CPU? Do you have another known working CPU to test with?

The CPU is supposed to have a fan. If that was run without a fan for any amount of time in the system that it came from it may have a fried CPU.

Yamaha YMF modified setupds and drivers
Yamaha XG resource repository - updated November 27, 2018
Yamaha YMF7x4 Guide
AW744L II - YMF744 - AOpen Cobra Sound Card - Install SB-Link Header

Reply 4 of 19, by Rwolf

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Intel CPU:s (in my experience) have OK thermal protection, a Pentium would normally just shut down when overheating, but it definitely needs a fan to run, yes.
That heatsink looks intended to have a fan mounted, though some cases can have ducts to direct airflow from a system fan over the cpu, and just use a passive heatsink. On a bench like this, it needs better cooling. (An AMD CPU is more likely to fry in the same situation, if overheated.)

Reply 5 of 19, by Doornkaat

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In one picture only a single 72pin SIMM is visible. Just in case you didn't know: Socket 7 chipsets all require 72pin RAM to be used in pairs of two logically identical sticks per bank. Otherwise the system usually won't start.
Especially early S7 boards can be very picky about SDRAM so I recommend you stick (haha) to 72pin SIMMs for troubleshooting.
Good luck!

Reply 6 of 19, by cyclone3d

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Rwolf wrote on 2021-06-09, 21:00:

Intel CPU:s (in my experience) have OK thermal protection, a Pentium would normally just shut down when overheating, but it definitely needs a fan to run, yes.
That heatsink looks intended to have a fan mounted, though some cases can have ducts to direct airflow from a system fan over the cpu, and just use a passive heatsink. On a bench like this, it needs better cooling. (An AMD CPU is more likely to fry in the same situation, if overheated.)

That CPU came stock with a fan that clipped to the heatsink.

Yamaha YMF modified setupds and drivers
Yamaha XG resource repository - updated November 27, 2018
Yamaha YMF7x4 Guide
AW744L II - YMF744 - AOpen Cobra Sound Card - Install SB-Link Header

Reply 7 of 19, by Rwolf

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Yes, unfortunately some (cheapo fan versions) were unreliable, after some years the fan started wobbling and could get stuck when the washer holding it in place failed. I saw a fair number of those on blades that failed when the fan tried to pull itself off the shaft.

Reply 8 of 19, by pc-sound-legacy

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C6 on Award BIOS is cache check. But I think you really need to install two ps2/Edo ram to get the board running. (With SD-ram a single one will be fine)
I wonder why you won't get beep error Codes. Do the codes on the diagnostic card change during boot? If so, CPU must be fine I guess.

Reply 9 of 19, by BitWrangler

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Rwolf wrote on 2021-06-09, 21:00:

Intel CPU:s (in my experience) have OK thermal protection, a Pentium would normally just shut down when overheating, but it definitely needs a fan to run, yes.
That heatsink looks intended to have a fan mounted, though some cases can have ducts to direct airflow from a system fan over the cpu, and just use a passive heatsink. On a bench like this, it needs better cooling. (An AMD CPU is more likely to fry in the same situation, if overheated.)

Thermal shutdown was a feature introduced on the Pentium 4, anything earlier may look like it shutdown because it locks up and the screen goes black, but it's just sitting there spinning it's little hamster wheels getting hotter. ATX PSUs were smarter than that from late 90s, so may shut down from system heat or excessive power draw.

Unicorn herding operations are proceeding, but all the totes of hens teeth and barrels of rocking horse poop give them plenty of hiding spots.

Reply 10 of 19, by cyclone3d

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Rwolf wrote on 2021-06-09, 22:28:

Yes, unfortunately some (cheapo fan versions) were unreliable, after some years the fan started wobbling and could get stuck when the washer holding it in place failed. I saw a fair number of those on blades that failed when the fan tried to pull itself off the shaft.

These were straight from Intel. I've never seen a bad one.

Yamaha YMF modified setupds and drivers
Yamaha XG resource repository - updated November 27, 2018
Yamaha YMF7x4 Guide
AW744L II - YMF744 - AOpen Cobra Sound Card - Install SB-Link Header

Reply 11 of 19, by soggi

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To all who say there's just one RAM stick, TO wrote that there a two sticks and you can see the second one on the second picture (lying beneath the MB). Nevertheless you'll need both sticks @son_dh, because EDO RAM has 32 bit data width and the socket 5/7 chipsets have 64 bit memory data width.

The following points have been mentioned before partially...

  • do a CMOS clear
  • have a look at the MB's manual concerning memory configuration
  • get a CR2032 battery
  • swap CPU, RAM, video card, PSU
  • get the latest BIOS for the board

If this all doesn't help (and the MB isn't defective) maybe the BIOS is corrupt or even the Flash is defective - so replace it with another one.

EDIT:
Did some "deeper digging"...
The BIOS ID should be "2A59GV5F" (got it from this thread on vogons) - therefor the board should be "Prime VT 586 VXC (also called Otto)", the encoded "V5" says the board is from "Vision Top Technology". This could be an OEM or reseller. Have to dig even deeper...

kind regards
soggi

Vintage BIOSes, firmware, drivers, tools, manuals and (3dfx) game patches -> soggi's BIOS & Firmware Page

soggi.org on Twitter - talent borrows, genius steals...

Reply 12 of 19, by son_dh

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Thanks for the advice. I do have a few Socket 7 CPU around, but I have to check on the jumper to set the correct bus speed for any CPU, right?

I have tried using both ram sticks with no avail, in slot 1+2 or 3+4.

How do I update the bios? Pry this chip out and flash it with a raspberry pi?

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I hope that I don't have to replace this rom chip, or I would have to order and wait for a month from aliexpress.

Reply 13 of 19, by soggi

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The FSB depends on the CPU you have, f.e. Pentium 75 -> 50 MHz / Pentium 120 -> 60 MHz / Pentium 133 -> 66 MHz. If you have a Pentium 133, you can definitely run it with all the FSB settings (you may underclock it). And don't forget to set the jumpers for the multiplier correctly.

Concerning the RAM you can also try slot 1+3 and 2+4, sometimes boards of this generation were odd.

The problem with BIOS update is that you have to find a suitable BIOS image from the manufacturer.

I don't believe that the EEPROM/Flash itself is defective...maybe the BIOS is corrupt or you just need a later BIOS version. If you have a suitable board, you can do a hotflash - boot the working board, pull of it's BIOS chip, put in the BIOS chip of this board (take care of the right direction!) and flash the latest version you can get with Uniflash 1.40 (available f.e. on my website -> https://soggi.org/motherboards/bios-update-fl … h-utilities.htm.

BTW the chip on your picture is not the BIOS EEPROM/Flash, it's the tag RAM. The former is located on the left side of the ISA slots, it has a glitter sticker saying "AWARD SOFTWARE ...".

kind regards
soggi

Vintage BIOSes, firmware, drivers, tools, manuals and (3dfx) game patches -> soggi's BIOS & Firmware Page

soggi.org on Twitter - talent borrows, genius steals...

Reply 15 of 19, by son_dh

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dataino.it wrote on 2021-06-10, 05:35:

Try turning on the card by squeezing the card chips one at a time. as I do in this video

http://www.dataino.it/vogons/video/20210601_221857.mp4

Wow I have never seen this method before. Did it help with your diagnostic on that board?

Reply 16 of 19, by dataino.it

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It is a procedure that I use when I repair the cards, it often happens that a chip or a component has bad soldering. Yesterday with this method I found the faulty clock capacitor on this card that in the pc worked once and 3 no.

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Reply 17 of 19, by son_dh

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Update: Hey it works! Turns out the PCI slot has bad connection, the computer made a beeping sound on boot when I accidentally hit the graphic card. Some cleaning later and ta-da!

Now what's next? I am still in disbelief myself that the motherboard work, had to pinch my cheek to make sure it isn't one of those retro-computer dreams.

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Reply 19 of 19, by evasive

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Hi, a page was created for your board:
https://www.ultimateretro.net/en/motherboards/11214

We would love to have good pictures from the front and back of this board as well as a bios dump if possible 😀

Can you check/verify if the manual for the VT586VXB is also useful for this board?
https://www.ultimateretro.net/en/motherboards/11210