COM1 not behaving...

[Guest]

Hi all.

I seem to have a stubborn serial port.

I just got a new motherboard, with one onboard serial port, and also have a
PCI expansion card with two serial ports.

After I installed the drivers for the expansion card I got an error message
regarding COM1 (the onboard port). I blamed it on a silly driver conflict,
forgot to write the exact error message down, rebooted the PC, and everything
was fine. Or so I thought...

Yesterday, when I started one of my programs that use all 3 COM ports, I
immediately got a "cannot open port 1" message. After checking the ports and
their settings in the device manager, I saw "this device is working properly"
for all 3 ports. Yet COM1 refused to work. 2 and 3 worked fine.

Blame it on pure luck, for some reason I disabled COM1, and then enabled it
again. And after that it worked. So I didn't investigate further.

This morning I start up my PC, only to find out that COM1 wasn't working
again. "This device is working properly". No, it isn't... So I decided to do
the disable/enable routine again, and sure enough, it worked.

I have gone so far as to uninstall/install COM1 through the device manager,
thinking that that would fix it. After uninstalling and rebooting XP (SP2)
picked up the "new" device, and installed the drivers. But again, the COM
port was not working until I disabled/enabled it.

Does anyone have any idea how I can fix this permanently?

Thanks,

Erik

 

[DL]

new mobo?
You have installed the chipset drivers?

 

[Guest]

Of course

new mobo?
You have installed the chipset drivers?

 

[DL]

Thats often missed

When you get the problem, any conflicts shown in Hardware Devices?
Any err.msgs in Event Viewer?
Tried the card in a different slot?

 

[Guest]

Hi DL.

Sorry for the late reply; I didn't get a notification that you had replied
again.

Often missed yes; but if I'd tell you how many times I've called the 1800
number for a new activation code (if I could remember...) you'd know that
I've done this "a couple" of times

To answer your questions:

1. No conflicts in device manager at all. Everything is reported as "working
properly".
2. Error messages in event viewer: lots! A little over 600 in the
Application tab, almost 2,000 (yep, two thousand) under the System tab. Many
of these entries are merely Information (about SP2 that was installed), some
are related to some CDROM issue (even though they appear to work fine); but
I've found a few that say "While validating that \Device\Serial1 was really a
serial port, a fifo was detected. The fifo will be used." I've done a Google
(oops!) search for this error message; but didn't find anything useful. Any
idea what that means? And, what else am I looking for?
3. I haven't swapped the expansion card to a different PCI slot yet, no. I
was kinda hoping that there is an easier (as opposed to opening the box -
again - and swapping cards around...).

Any ideas?

Thanks,

Erik

 

[Bob I]

Just a thought, you could try killing mouse detection on the serial
ports with the /fastdetect switch.

Available switch options for the Windows XP and the Windows Server 2003
Boot.ini files
http://support.microsoft.com/kb/833721/en-us

 

[DL]

With that amount of event viewer err.msgs you've got something going on,
which aint right

 

[Guest]

Thanks Bob, but that switch is already present in boot.ini. I suspect it's
the default.

 

[Bob I]

You say "3 com ports". You wouldn't happen to be trying to "force" IRQ4

 

[Guest]

Nope, not forcing anything.

COM1 has its own IRQ. COM2 and 3 share IRQ 16.

What's weird though, is that I just noticed that COM1 now has IRQ 7 (not
shared with anything else), while it had IRQ 4 yesterday (again not shared).
And I swear it's always been 4 in the BIOS...

 

[Bob I]

Interesting, perhaps the BIOS is handing off 4 and OS is assigning 7
because it thinks 4 is used and there is the error message?

 

[Guest]

Oh, it's interesting alright!

I have gone into the BIOS, and changed the IRQ to 3, with its corresponding
memory range. I have also removed the /fastdetect switch from boot.ini.

Device manager now shows me that COM1 has IRQ 3, and the default memory
allocation as shown in the BIOS.

Now, when I start my PC, right before my mouse lights up, my device
connected to COM1 clicks (relays) as it has done for all the years that I've
been using it. So that's OK.

However, something must still go wrong after those drivers are loaded,
because my programs still say that they can't open COM1.

After some more digging in the device manager, looking at the resources by
connection, when I go to COM1 I see that there's a small, blue letter "i" on
top of the serial cable icon. It also did that when it was on IRQ 4 (7).
There are no memory allocation overlaps.

It seems like Windows is trying to tell me something ("i" for
"information"?); but I can't find more info about that "i"...

I have gone through the event viewer again, but there are no new errors
concerning the com port. Still, it doesn't work as expected.

Any other ideas?

Erik

 

[Bob I]

Double click on it, it will open Properties, there is a window that will
provide the info about the error.

 

[Guest]

I'm afraid it doesn't. It shows the exact same information as in the device
list, and nothing else than "this device is working properly"...

 

[Bob I]

After looking through the properties, what changes from "before" you
disable/enable to afterwards?

 

[Guest]

Not a thing. IRQ's the same, memory allocations, nothing changed to speed
settings, FIFO, etc. And the "i" is still there. The only difference is that
before it doesn't work, and after it does.

 

[Bob I]

Can you set the COM1 to IRQ4 in the BIOS AND Device Manager? See the
Resources tab in the Com port properties.

 

[Guest]

Hi there.

Sorry for the late reply. I work weekends and holidays only, but many, many
hours...

I've just tried what you suggested, and that works. That is to say: I can
set it to IRQ4, both BIOS and device manager.

But the problem remains; I still have to disable/enable the port to make the
port communicate with my software.

I have decided to start from scratch, with the oh so familiar format
command. See what that does. That may not be today, but I'll keep you posted,
as you seem genuinely interested.

Thanks,

Erik

 

[Bob I]

That is quite strange, sorry we could not discover the reason for the
issue. It will be interesting to find if an "update" was responsible.

 

[groups]

Related information from my personal experience.

Intel 945 motherboard. One onboard com port address fixed at normal
com1 baseport address and irq. Reboot system and Device Manager sees
it and describes it as normal. Applications can not talk to it. Hang
a modem on it and Applications can not talk to it. Open a cmd prompt
and issue atdt 12345 and watch lights on modem. Return to Winxp and
aps can not communicate. Remove in Device Manager and reboot and aps
can communicate. Reboot and it is not available to applications.
Each reboot is shows in Device Manager as functioning normally.
Minimum steps to render it useful to programs without removing from
Device Manager and rebooting.
Open Device Manager after reboot. Select the Com port properties.
Select the Resource Tab and toggle the USE AUTOMATIC SETTINGS
selection box. Select OK and watch the Device List get reloaded.
Device is now available to the application. Didn't even have to close
the ap that loads automatically at boot to communicate with a serial
device that is always connected. Fastdetect does not seem to apply.

Seems that WinXP Pro does not see it after a reboot unless it is
forced to reload it. This goes beyond you technical experience. I do
not know what exactly happens when that list is redrawn ... reloaded
but whatever it is it allows applications to communicate with the
port.

This is XP sp2 and my BIOS is current. I do recall when we purchased
the original XP a friend had a KENSINGTON Trackball that was required
because he is disabled. Kept loosing the mouse and discovered that
removing and rebooting brought it back.

The question is: If the activity that takes place during this
reallocation or scan or whatever Device Manager is doing is something
that can be forced automatically on boot, how can that be accomplished
to remove the need for this manual change?