From: "John Murray" :Sent: Monday, May 14, 2001 4:13 PM
Subject: [PCBUILD] Changing Processors


> Hi Folks, hope someone can help me. I am living proof that a little knowledge is dangerous. I got hold of an Intel Pentium Overdive (that's what it says on the sticker attached to the on-board fan) and I thought I would try swapping it for the CyrixInstead processor I am currently using. No joy there though, as the computer wouldn't boot so I swapped them back and everything's hunky-dory. A friend of mine is having trouble with a noisy processor fan in his tower system and I thought that this spare processor might be swapped for his Intel Celeron processor thus maybe solving his noise problem, but if performance suffered we would swap back. Now, there must have been something I didn't consider before rashly charging ahead because the Pentium processor didn't even start. Instead, I noticed a slight electronic burning smell that I didn't like at all! When the original Celeron processor was returned it wouldn't start either. I would be grateful if someone could help me get my mates computer going again and restore my good name. Thank you John Murray
> 

John,

There are a few things that you failed to take into consideration when you swapped out the processors.  First you needed to find out if the motherboards that you installed the overdrive processor onto supported the processor that you installed.  There are many different kinds of Pentium processors, which support different clock multipliers, external clocks, different single voltages and even dual voltages for the processor.  Most older motherboards require you to set jumpers on the motherboard to support the processor that you are installing.  Some of the older motherboards only supported a certain range of processor before you had to upgrade to a new motherboard.  Newer motherboards auto detect the processor but can also be set manually through the use of a menu or jumpers on the motherboard.  

Whenever one plans to upgrade a processor on a motherboard, the documentation for the computer or motherboard needs to be checked to see what processors , voltages, clock frequencies, and on older motherboards what clock multipliers the motherboard supports.  Newer processors are clock multiplier locked by Intel so this setting can no longer be changed.  All of these setting must be changed to match the processor that is going to be installed prior to the installation, either through jumpers on the motherboard or through a menu in the BIOS.  

You did not mention any details on the motherboards involved, the speed and kind of overdrive processor or the speed and type of Celeron processor involved.  Without more details it would be hard to venture what has happened.  Your best bet at this time may be to take the computer to a repair shop with all pertinent information about the processors, etc and have them check out the processor and motherboard.
Good luck.

Mary Wolden

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