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Internal modem stops monitor working

By lynz67 ·
I built a my computer in October last year and have installed the full version of XP Home OS (Service Packs inclusive). I have not used an upgrade version and until now there have been no issues with this machine.

Three days ago I fdisked my machine to remove XP Pro (no Service Packs) and installed XP Home and I bought an external modem at this time. I used to use a SwannSmart IIx 56K V.92 internal modem but now have a Netcomm 56K V.92 USB external modem. I am able to unistall the internal modem without any problem however once I remove this internal modem from the PCI slot the monitor doesn't work until I put the modem back in the slot.

It seems to me that the internal modem has been identified as a graphics card and I am at a loss as how to fix this issue considering that located in the AGP slot on my motherboard is a Radeon 256MB graphics card.

My computer spec's are as follows:
2.8GHz Intel Celeron Processor
Asus motherboard with 533MHz FSB
512MB SDRam
256MB Radeon Graphics card
2 x HDD (1x40GB and 1x80GB) both IDE
2 x Burners (1xCDRW and 1xDVD Dual Layer burner)
Antec system case with front and rear fans

I have checked the computer's IRQ and BIOS configuration but nothing stands out as being wrong. No error messages are being generated and according to system information and DR Hardware 2005 v6.0 there are no conflicts to resolve.

I would really like to resolve this issue and remove the internal modem but I don't know where to start or what to look for.

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by willcomp In reply to Internal modem stops moni ...

Do you get a display during POST? If so, remove modem, enter BIOS setup, and reset ESCD.

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by lynz67 In reply to

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by lynz67 In reply to Internal modem stops moni ...

The only time I get the POST display is when the internal modem is in the PCI slot. Can I reset the ESCD prior to removal of the internal modem, with the same result.

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by lynz67 In reply to Internal modem stops moni ...

I tried the 1st suggestion of yours but it didn't work so I removed the internal modem and reset the jumper on the motherboard but to no avail, when
I reconnected the computer without the internal modem after resetting the jumper the monitor still won't work until I put the internal modem back in the PCI slot.

I thought about leaving the internal modem in permanently but I don't know if it is going to cause further hardware conflicts later with any of the current or future hardware installed.

Do you have anymore ideas that I could try.

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by HAL 9000 Moderator In reply to Internal modem stops moni ...

Well I don't know just how good this will be but first remove the Internal Modem and then change the jumper setting on the M'Board to clear the BIOS this generally involves moving a single jumper from pins 1 2 to pins 2 3 then after a short time reset the jumper to pins 1 2 and try rebooting. You should get a Checksum Error because you need to enter the BIOS to at the very least allow it to recognize the available RAM as well as setting the Date/Time.

That should put you back to a Factory Default situation and you should be able to at the very least get a POST screen from there.

Just a word of warning with XP and an external Modem they do really work great but you have to have the modem turned on at boot up so it can bee seen by Windows or that port will be blocked. Once it is booted you can switch off the modem and only turn it on when required. If you don't boot up with the external modem turned on you will not have a working modem in the System items section.


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by lynz67 In reply to

Poster rated this answer.

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by lynz67 In reply to Internal modem stops moni ...

I have already removed the Internal Modem and then change the jumper setting on the M'Board from pins 1 2 to pins 2 3 to clear the BIOS and after 30 seconds reset the jumper to pins 1 2 and tried rebooting. The monitor still won't work, so I can't enter the BIOS to allow it to recognise the available RAM or set the Date/Time.

Even with resetting the jumper to go back to factory default configuration there is still no visual display from the monitor unless I put the modem back in the PCI slot.

If the modem is put back in the PCI slot I get a visual display and I can see that it has been changed back to the Factory Default situation and get the POST screen.

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by lynz67 In reply to Internal modem stops moni ...

Point value changed by question poster.

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by Jessie In reply to Internal modem stops moni ...

Just a thought... perhaps it's a bad PCI slot, that when you remove the card from it, it's shorting itself out? Will it come on if you put in any OTHER PCI cards?

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by TheChas In reply to Internal modem stops moni ...


What an interesting problem.

I agree with Jessie that this is most likely some sort of hardware issue and not a BIOS or IRQ issue.

The first step is to try putting a different PCI card in the slot that the modem has been in.

Use a sound card, a USB card, or anything else.

Also, try placing the modem in different PCI slots and see if a different slot changes how the PC boots.

If you get a POST display with a different card installed, here is what to look for:

1. A short between the case and the motherboard.
This could be a long lead on the motherboard, or a raised portion of the case.

2. A poorly seated AGP card.
Many a time I have fought video problem because of an AGP card that was not fully seated in the AGP slot.
The "quick" test for this is to remove the metal slot bracket from the AGP card and carefully seat the card into the AGP port.

3. A poor ground connection that is completed when the modem is installed.
You don't necessarily want insulating washers on all motherboard mounting screws.

4. A motherboard manufacturing defect.
Having a PCI card installed in the slot you had the modem in may be flexing the motherboard just enough to allow an unsoldered connection to have a good physical connection.

The motherboard could also have a bad voltage regulator that needs the additional load of the modem to bring the voltage into specification.

5. Case fans:
This is another problem that has caught me off guard from time to time.
Some case fans generate too much electrical noise and cause problems when plugged into the motherboard fan connectors.
Unplug the case fans and see what happens.

As far as power issues are concerned, it might be worth the effort to swap in a different power supply.

All in all, the more I think about this, if I were to swap out any single part, it would be the motherboard itself.


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