I installed an ADSL2+ modem, and my computer restarts randomly...?

Question

Model: Huawei MT882

XP SP2, add-on network card (Intex)

1. Never had random restarts earlier.

2. The modem can be installed either via USB or via Ethernet port. Some people told me it's unstable on USB, so I connected it to the Ethernet port. It couldn't be detected on my on-board (nForce) LAN, so I plugged in a network card.

3. Drivers for this modem are available, but they aren't needed. In fact, the driver setup can't find the modem.

4. ADSL connection is fine, but the computer restarts randomly every half hour or so.

5. One lead... when I'd first connected it to the USB port, and switched off the modem while the computer was on, the computer restarted (exactly when I switched the modem off). But then, it's on the LAN card now, not USB.

So is the problem with the DSL line (something data on the phone line that's causing restarts), or with the modem, or with the network card? Please help!

Cheers, and have a nice day!

Answer 1

I don't have an exact answer for you, but here's some thoughts. I don't see how any ADSL (or cable or other) modem could be the culprit of the random restarts. I've been working with networked computers using Ethernet for over 20 years, and I've never seen this even once. I also had DSL (both SDSL and ADSL from three different ISPs) for about eight years at my house (until I got fiber Internet) and never saw what you are seeing.

The only thing that I could think of that might do this is if there is if your computer was responding to SNMP commands and the router was sending them out. Very highly unlikely.

I'd be more inclined to think that you need to update the driver for the new Ethernet card you put in, the driver isn't compatible (if it is the latest version), the network card itself is not compatible, or the network card isn't installed properly.

- Checking for the latest drivers should be easy enough. Get them from the manufacturer of the card if possible.

- Check that the drivers of your built-in Ethernet adapter aren't interfering/conflicting with the ones from your card.

- Try disabling the on-board Ethernet in your BIOS settings to make sure it's not causing a device conflict with the add-in card?

- Check that the card is seated all the way in the (PCI?) slot as well. If it is not, it could be becoming disconnected momentarily and causing the reboots.

- Uninstalling the driver and the card would be a good test, too. If that helps, try installing the PCI card in a different slot. I've had cards that (because of the interrupt they got assigned due to the slot they were in) caused instability in one slot and worked fine in another.

I agree on installing the modem using Ethernet rather than USB. I have just heard of too many people having problems with the USB connection. (They are almost always driver issues, not hardware specific ones.) Also, Using USB doesn't let you use a router/firewall to set up a home network. For your point in item 5, I have had misbehaving USB devices that cause my computer to freeze or blue screen the moment they are plugged in. In some cases, I think it was an actual hardware issue and not a software issue.

I am curious that your build in Ethernet port didn't work with the MT882. Ethernet is pretty well standardized, now. I'd be surprised if your modem's Ethernet port is truly incompatible with your built-in Ethernet. When you were trying that, did the link LEDs light on the modem and the built-in Ethernet port light up? (The built-in Ethernet may not have LEDs, but if it does, they'll usually be right next to the plug. One of them will light up the moment the cable is plugged in to signify a link was detected.) If it's not lighting, there are two issues that I know of that it could be: crossover issue or link speed issue.

In order to test the crossover issue, in addition to what I assume is a "straight though" normal Ethernet cable that you used, did you also try a crossover cable? Many DSL modems come with their "LAN" ports set up assuming they will be connected to a router or switch rather than another computer. Your built in Ethernet may not have auto MDI/MDIX switching, but the add-in card may, which would explain why the built in Ethernet adapter did not work. The reversal of the transmit and receive lines is much more likely.

The second issue, link speed, is something a little investigation would reveal. If the LAN port of the MT882 is 10 Mbps max (i.e., 10 Base-T), but your computer's built-in Ethernet port is 100/1000 Mbps (i.e., gigabit Ethernet), the two devices won't talk even if the transmit/receive polarity was correct. However, checking http://www.huawei.com/products/terminal/... , I found that the WAN port on the modem is 10/100 Mbps. Unless your built-in Ethernet was locked to 1000 Mbps, the two should negotiate a suitable speed. I suspect this is not the problem. A suitable 10/100 (or 100/1000) Mbps switch (not a router, just a regular hub or switch) inserted between the computer and modem would fix the issue.

What I would really recommend is removing the new Ethernet adapter from your computer and trying a crossover cable with the modem and the built-in Ethernet adapter. That really ought to just work, so I'm thinking it's a transmit/receive polarity issue.

** edit **

Noticed this note on page 8 of the users manual: "Note: Use cross-over cable to connect MT880 and the uplink port of a switch or hub. Note: The attached Ethernet cable in the packing box is a straight-through cable. Be sure that the cable connecting the LAN to MT880cannot exceed 100 meters"