Troubleshooting Installations

Troubleshooting Installations

So you pulled the computer to bits, and it went okay. You put it back together, and everything seemed to go smooth. But now your computer won't boot. What do you do?

Unfortunately, you can disassemble an entire computer and put it back together in the exact same way and still have troubles.

BIOS/CMOS

The most common problem that occurs when reassembling a computer is that the BIOS is reset. On many motherboards this is no longer a problem, as they load in a set of bootable settings anyways. On older boards that don't have this ability, you have to re-install your basic settings for the computer.

The most common problem is lost IDE settings. This is obvious because your hard drive won't boot. Go into your BIOS and look under the IDE Settings page. It should have a setting to state something to the effect of "Re-Initialize IDE Settings". Basically, you want the motherboard to search for your hard drives. Once it's done, save and exit the BIOS and the computer should boot.

There are also about 40 more settings in your BIOS that you shouldn't touch. Stuff lime SDRAM Timing, AGP burst speed, and CPU cycle speed should be left until you have the system working. If you mess with those settings before you have the computer operational, you may never find the source of your problem. If you change one of these settings and you don't know how to change it back, you can always choose the Load BIOS Defaults option to restore your BIOS to it's factory state. (Although you'll probably have to re-search for your IDE properties again.)

Cabling Problems

With all the cables you've had to run, it's not uncommon to turn on backwards or forget to hook one up. This includes your power, which can cause all sorts of weird errors if not hooked up correctly. Here's a quick list of errors and their symptoms;

Problem	Symptoms	Solution
Floppy Drive Errors	Floppy Drive activity light stays active on boot, system won't pass floppy test.	Check to make sure you have the floppy drive cable the proper way. It isn't keyed, so it's easy to put on wrong. Also make sure you have the right type of floppy drive selected in the BIOS. Make sure you connected to the connection AFTER the twist in the cable for Floppy A:
Hard Drive Errors	Hard Drive doesn't spin up, computer asks for system disk to boot.	Make sure power is connected to your hard drive and that you have not forced the hard drive cable in backwards. Also make sure your hard drive selections are correct in the BIOS
System Won't Boot	Nothing happens when you turn on the computer.	Normally this is a power problem. Make sure you have your main power connector in place, and on AT boards that the black wires on each connector are beside each other in the middle. Also make sure you have the Reset switch connector the proper way on the motherboard. If all else fails, make sure the power input switch on the back of the power supply hasn't been set to 220.
Keyboard Boot Error	Computer gives a keyboard error on boot.	Make sure you have the keyboard plugged into the keyboard PS/2 connector. Make sure your PS/2 mouse and keyboard connectors aren't reversed.
CD-ROM/CD-RW/DVD drive won't function	CD/DVD drives don't show up in My Computer.	Make sure the connections to these devices are in properly, as well as in the motherboard. Ensure power is hooked up to each device. Lower DMA and PIO modes in the BIOS for CD/DVD drives until they function.
CD Drives Won't Function Properly	Sporadic Buffer Overflow Errors, especially when copying CD-to-CD-RW.	This error occurs when you attempt to use two CD-type devices on the same IDE chain, especially during the copy process for CD's. If you can, try to separate the devices on to separate IDE channels, or copy the information to a disk image before burning.
Computer Made a Loud Noise, now won't boot.	Smoke coming from the power supply.	This can happen for a number of reasons. Putting the power connectors on backwards, shorting a power connector or solder joint to the frame of the computer, or connecting the power LEDs to the switch incorrectly will fry your power supply, motherboard, CPU, RAM, hard drives, and anything else the short reaches. Replace the power supply, and hope you didn't fry the whole motherboard.

IRQ and I/O Address Problems

Another common problem is for the I/O addresses and IRQ settings of individual components to conflict. This often occurs because of new components being installed or old components being installed in different slots. This can also occur if you remove the CMOS battery or reset the BIOS to defaults.

If you have a Plug-and-Play BIOS, this is easy to fix. Simply go to the BIOS, look in PnP settings, and hit PnP Reset. This will tell the motherboard to re-assign all it's IRQ and I/O addresses, and as long as all your equipment is PnP it will eliminate the problem.

If you don't have a PnP BIOS or all your equipment isn't PnP compatible, it's time to start looking at jumpers. Try to find two pieces of equipment that are set to the same IRQ or I/O address and change one of them.

The last common problem is with serial ports. Often times when you install a modem it's default is to use the same IRQ as COM 2. If you have COM2 enabled on your motherboard, you'll get a conflict and Windows may crash when you try to use your modem. Simply disable COM2 (If you're not using it, which you most likely aren't) and this problem goes away. PnP modems will avoid this problem all together, but PnP didn't really take hold in the modem market until well after it was established everywhere else in the computer. Older modems can be a pain in the hind quarters, so watch for this problem.

Testing Your System

Although many errors in your system present themselves fairly quick, some errors may not be so obvious. Therefore, you should try to test a system after it's been re-built. I personally recommend Sandra from SiSoft. You can download the demo version of it at http://www.download.com/ , and it does a more-than-adequate job of testing the system even in demo mode. It will test every component of your system, benchmark it to ensure your settings are maximized, and give you warnings and tips on how to improve your setup. Overall, it's much better than hunting for errors the old fashion way. (test your video card with a video game, your sound card with a sound utility, your RAM with a RAM tester.... you get the idea)