Member Avatar for dro

I somehow made it impossible to use a PCI Express card on my ASUS A8N-Sli motherboard. This is what I did. I put a Diamond Supramax PCI modem card in the bottom PCI slot on my motherboard. This modem had been working in another computer. But now it caused the system to crash and when I tried to reboot, my ATI X1800 XL video card would not post. There was a long beep and the audible message: System failed VGA test. This keeps occurring even after I took out the modem card!!

Since I couldn't get into the BIOS I put an old PCI video card in one of the PCI slots and it booted up fine. Then I tried to go into BIOS and find out what might be wrong. I tried a couple of things, like making my PCI Express the primary boot and choosing Single video card but nothing works. I went into system to see if there was an Interrupt conflict but couldn't see anything wrong there either. Does anyone have a suggestion?

  • 4 Contributors
  • 5 Replies
  • 226 Views
  • 1 Month Discussion Span
  • Latest Post Latest Post by jarha

Dani AI

Generated

A few clarifications and a focused troubleshooting flow that follow from 's tests (X1800 XL works in another PC; system boots with a legacy PCI card; CMOS jumper/battery clear was already attempted) and the suggestions from and . The symptom (long VGA-fail beep, no POST with the PCIe card) most often points to one of: a dead/disabled PCIe lane or related power rail, firmware that will not initialize the card, or a hardware short/damage caused by the added modem.

Recommended diagnostic flow:

  1. Minimal bench test — remove all non-essential devices (all other PCI cards, extra HDDs/DVDs, USB devices). Fit a single RAM stick in the correct slot, plug in CPU, GPU, PSU, and speaker only. Reseat the PCIe card firmly and confirm any auxiliary power plug is attached. Boot and watch beep/LED behavior.
  2. PSU check — swap with a known-good PSU or check 12V rails with a meter. A GPU that works elsewhere can still fail to initialize if the local PSU auxiliary rail is weak or missing.
  3. Slot isolation — if the board has a second PCIe x16 slot, try the card there; otherwise try a small, known-good PCIe card (or the modem) in the suspect slot to see if that slot is dead. Inspect the slot area for bent contacts, solder splashes, or burn marks around the bottom PCI where the modem went.
  4. Deeper CMOS discharge — power off, unplug mains, remove battery and move clear jumper, then press and hold the power button 10–15 seconds to discharge caps, wait a minute, restore and boot. (This is more thorough than a short battery pull.)
  5. Firmware as last resort — reflash the official, stable A8N‑SLI BIOS only (match exact board model/revision). Follow the vendor procedure exactly; improper flashing risks bricking the board.

If the minimal bench + PSU swap + slot isolation still fail, the most likely outcome is motherboard-level damage to the PCIe lane or nearby power circuitry and board replacement or RMA is the pragmatic next step. This also aligns with seeing the same behavior after an HW change.

Recommended Answers

All 5 Replies

Member Avatar for nizzy1115

pull out your cmos battery for about 10 seconds to clear the bios and reset it. put it back in and fire it up. see if it posts then.

Member Avatar for dro

Nizzy1115, I will follow your advice to take out the CMOS battery and reset the CMOS. I am wondering why the Diamond PCI modem could cause so much trouble with the PCI Express video and is there a way to have a modem in this computer? It is an ASUS A8N-sli and I am running Windows XP Pro.

Thanks, Dro

Member Avatar for dro

pull out your cmos battery for about 10 seconds to clear the bios and reset it. put it back in and fire it up. see if it posts then.

Well I took out the CMOS battery and moved the jumper to pins 2 - 3 as the ASUS manual advised. I moved the jumper back to pins 1 - 2 and reinstalled the battery. However, there was no change in my problem. The same long beep (a beep a beep), then nothing. No post, no video.

I have made some progress though. I was able to check my video card on another machine and it works fine. So that reduces the problem to the mother board or the CPU. It seems unlikely that the CPU is at fault since I can run the computer fine using a PCI video card.

Does anyone have a thought on it? Is it likely a motherboard failure or a setting that got changed by the modem and even clearing the CMOS hasn't restored it back? (And if so, how can it be reset?) Thanks for your input. Dro

Member Avatar for Chaky

I have identical mobo an had a problem with one modem. I seems whenever I try to use the modem system reboots. No effect on the VGA, though.
I suggest flashing your BIOS to with and setting it up on defaults in BIOS setup.

This BIOS update is for the ASUS A8N-SLI ONLY!
Not A8N-SLI SE, A8N-SLI Deluxe nor A8N-SLI Premium!

Member Avatar for jarha

Hi!
Have you managed to solve this problem? I have a same situation. Made some changes to the HW configuration and now the PC wont post with PCI-E card. Old PCI card works just fine and the PCI-E card works in another machine.

ASUS A8N-SLI
ASUS EN6600 silencer PCI-E


-jarha

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.