"IRQ3 CONFLICTS WITH ONBOARD SERIAL PORT"

[Ichinisan]

I am doing a favor for a coworker who dropped off his computer with me to "fix the sound" and install a PCI USB card.

The computer is an old Acer Aspire, with an unreplaceable proprietary motherboard.
Pentium 166Mhz
Integrated ATI Mach64 video
PCI Modem
PCI NIC
ISA Soundcard
ISA Parallel expansion (for HP scanner)

Having experience resolving conflicts with ISA devices, I decided to fix his existing the "no sound" issue before installing additional hardware. I connected the keyboard and display and attempted to boot. During POST, I received the error message "IRQ3 CONFLICTS WITH ONBOARD SERIAL PORT". I pressed F1 to continue. The computer immediately restarts after the Win98 splash screen. Booting to the command line with F8, I scanned the hard drives. In safe mode, I removed all hardware through Device Manager (everything). In the CMOS setup, I reset to default settings and looked for any IRQ configuration options. There were none (the setup program is really dumbed-down), so I rebooted. Win98 started successfully and recognized hardware, then required a restart. After restarting, it returned to the endless loop at the Win98 splash screen.

I called the coworker. He had never received any "IRQ3" error message, even though his sound was not working. And he never had any problems getting Win98 to boot.

I tried removing every piece of hardware except the keyboard, monitor, main hard drive, and a single bank of memory. Then I tried reseating the processor and swapping the bank with the other. The problem remains...

I will try re-installing Windows, but would like to know why I receive the conflict error, even when there is no additional hardware. Honestly, I think his computer is totally borked. If there is a way to fix this, please help! I don't want to look incompetent. (*gulp*, I hope he doesn't think "I" borked his machine)

 

[Ichinisan]

(bump cuz i gotta run)

 

[Lord Evermore]

Remove the CMOS battery from the board for 10 minutes. This should make sure that all the settings are gone. Then see if the CMOS setup has an option to reset ESCD data or reset configuration data. It sounds like the board isn't clearing the IRQ assignments when you remove the devices. You could also disable the COM2 serial port in the CMOS, since that's the port that uses IRQ3 by default.

I don't know why this would have suddenly started happening to the machine, of course. You should check the settings on the sound card and the parallel card to see what IRQs they're trying to use. Maybe a jumper cap fell off.

 

[Ichinisan]

Sorry, I had already tried removing the battery. I forgot to mention it.

It did not work.

The BIOS does not have the ESCD option, I tried looking for it before and realized how restricted this setup program is.

 

[Ichinisan]

Oh yeah, no way to disable COM/Serial ports either...

 

[Lord Evermore]

Did you try putting devices back into different slots? Usually certain PCI slots will be shared with some onboard devices. I really can't imagine what is causing such an error.

 

[Ichinisan]

I tried removing the entire riser containing all expansion slots, still the same error appears

 

[MadRat]

Good settings for your comm ports:

COMM1 - IRQ4, 3f8
COMM2 - IRQ3, 2f8

I typically save IRQ11 for the modem and IRQ9/10 for the NICs.

 

[Lord Evermore]

He can't change that sort of setting in CMOS, and Windows usually won't let you change things (and of course he can't get into Windows now). It's the BIOS giving him the conflict error.

 

[bozo1]

Are your ISA cards 'plug & play' or not?

Sounds to me like either the ISA sound card or the extra parallel port is not - and I've *rarely* seen a parallel card that is.

Look at the jumpers/switches on either the sound or parallel card - I bet that is your conflict - either IO address or IRQ assignment with something built-in. <- Remember that your built-in serial and parallel ports do use an address and sometimes an IRQ whether or not they have anything hooked up to them.

 

[MadRat]

Originally posted by: Lord Evermore
He can't change that sort of setting in CMOS, and Windows usually won't let you change things (and of course he can't get into Windows now). It's the BIOS giving him the conflict error.

He should be able to configure Serial and Parrallel ports in the CMOS. If it has a conflict he can test by simply removing one card at a time until the error goes away.

 

[Ichinisan]

Can't configure any IRQ settings in this simplified CMOS setup...
The sound card has no configuration jumpers.
The Parallel card has 1, tried the other position already...no dice

Remember, I got the error even when I removed all expansion cards. I checked BOOTLOG.TXT, the last line indicates that it restarts after "ENUMERATING...COM PORT 2" (something like that).

Anyway, I "sorta" fixed it. I disabled all COM devices while booted in safe mode and it finally boots normally.

I played around in the device manager re-enabling the COM ports and I cannot get one of them to enable. Windows is automatically disabling one of them without giving a reason (as if it were manually disabled). When I enabled the other COM port, the computer immediately restarted and got stuck in the same endless loop; indicating that this motherboard can't handle configuration via OS.

 

[MadRat]

So what IRQs are using what? Use WINMSD from the Start - Run command line. Click on Conflicts/Sharing.

 

[Ichinisan]

WINMSD does not appear to work with Windows 98.

 

[MadRat]

Oops. You want "msconfig".