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Thread ID: 26564	2002-10-30 06:29:00	Disappearing Modem	andyp (1790)	Press F1

Post ID	Timestamp	Content	User
94585	2002-10-30 06:29:00	I have recently bought a second hand modem & am having problems with it disappearing. It is an External 3Com US Robotics 56K Fax Modem running on Com1. OS is W2K Pro. More often than not when the PC boots up the modem has gone & I have to re-install again. Any ideas?	andyp (1790)
94586	2002-10-30 06:47:00	sorry i cant help you with this one. i have the same problem with a dse external modem on winxp pro. it happens irregularly but often enough to be a pain.	matt (727)
94587	2002-10-30 06:59:00	Where is your mouse connected? I use an External Modem under WinXP Pro. Modem connected to Com2. Mouse connected to PS/2 My modem doesn't disappear.. Have you checked Control Panel, System, Hardware and found any conflicts?	Elephant (599)
94588	2002-10-30 07:44:00	Checked behind the couch? That's where a lot of things that disappear in my house end up! But seriously, beck you BIOS to see if the serial ports have been assigned 'auto'. If so it could be worth setting the to specific address(es)	crozier (2004)
94589	2002-10-30 07:44:00	You may find that if you boot your computer with the modem "off" this may happen. I dont know the answer, apart from making sure the modem is powered up first.	godfather (25)
94590	2002-10-30 08:22:00	I agree with the suggestion of your mouse conflicting with your serial port, but this usually only happens when you have a serial mouse. A PS2 mouse does not rely on the comm ports, so it should not conflict. I would suggest you rule out any possible hardware failures by trying the modem on another machine to see if you get the same problem. I had a troublesome external device that always configured itself perfectly every time, but almost every time I went to use it, it broke down. The problem was a faulty power supply. I replaced the PSU & the item works perfectly. Being an external modem, it should have its own power supply & there should be a bank of LEDs on the modems front panel or top to indicate the modems status. If you didn't get a manual, try downloading one from the manufacturer if there is anything available & observing the indicator lights to get a clue as to what's happening. I have worked with external modems before & they all flashed about 3 different sequences during the boot process. Check the LED activity against the manual to see if any error codes are being displayed. If you're not getting any LED activity, then it's possible your modem or the connection between your modem & PC is breaking down, or the modem simply isn't getting enough power. If your PSU is a switchmode unit, the circuitry may be damaged. Don't rule out past voltage spikes if you purchased your modem from a rural district. These can & do regularly destroy modems. (I live in a rural setting & have spoken to many that have had their modems fried by the constant spikes & phone lines picking up electric fence pulses etc...) Another place to check is the device list. Back in the days of Win95-ME, starting your PC in safe mode enabled the device manager to display every device installed whether it was connected & working or not. Starting in normal mode hides many phantom items. I don't know if Win2K Pro does the same, but it's worth a try. Chances are you may see multiple occurrences of the same device (modem or comm port). If so, then delete them all, then restart your PC & let it reconfigure them. Before you restart, you'll have to delete any *.inf files associated with the modem & check your add/remove programs dialogue box for any enrties concerning the modem. If there are any, remove them too before restarting & try reinstalling the modem. Normally the *.inf files are in the C:\WinNT\Inf\Other\ directory. If you're unsure, open the inf file in notepad & look for text with the word "modem". If you find one, then it's safe to delete it. Another place to check is your BIOS. Depending on youre motherboard manufacturer, there may be a few different ways to access your BIOS, normally it's done by pressing the DEL , ESC, F2 or a combination of keys. Check yor motherboard manual for the correct procedure. What you're looking for is a setting relating to the PNP/PCI configuration. Check the Plug & Play OS setting & set it to "auto" or "yes" if not already. Of course, you can do the opposite, but auto is best. The auto setting alloows the BIOS to handle only the devices required to boot the PC, then the rest are handled by the drivers on HDD when initialised. When set to manual, the BIOS handles more devices & the software just follows suit. Check also the settings for the IRQ's. In some BIOS'es you can reserve a setting or an IRQ/COMM port for legacy devices like older modems. Mike P	mikep (1856)
94591	2002-10-30 11:13:00	I'm running win2000 and have the same problem. If the modem is turned on when I boot it is OK but if it is off there is supposedly no modem. Some one posted previously that with 2000 if when booting it doesn't detect something it won't load the drivers hence the problem.	mikebartnz (21)
94592	2002-10-30 11:19:00	The serial externals only seem to be detected at bootup. If it is powered down after bootup, the OS will give an error and can disable the port as well. One easy fix I used was to supply all these devices (including monitor) from a power strip that was activated by a Triac controlled by the USB port (opto isolated). As soon as you power up the PC, all the peripherals power up, and power down when the PC powers down. It won't work on my present PC as the USB stays alive unless the PC is unplugged...but I am on ADSL now anyway.	godfather (25)
94593	2002-10-31 07:03:00	Thankyou everyone I will try the suggestions & see how I get on. For the record I previously had a 28K External modem & had no problems at all with that one (apart from speed)	andyp (1790)
94594	2002-10-31 21:11:00	Heaven forbid that I question God's word :) But at least in Win98SE with a 56K US Robotics External Fax Modem attached to Com2, it doesnt matter whether the modem is powered, or even plugged in at start up. As long as the drivers are there Windows thinks that there is a modem, it's not clever enough to detect past the com port to see whats on the end of it! The com port acts as a buffer. Device Manager says the device is working properly even when it's unplugged. Plugging the modem in and powering it up AFTER starting Windows, gets it going. This posting just tested that out. Incidently some m/bs have a slower UART in COM1 than COM2, so it's better to connect to COM2. if that's the case. So if Win2k is not all that much cleverer then the problem is likely to be software based, the drivers not "sticking" or something. Sorry can't be more informative than that.	Terry Porritt (14)
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