Altair-what do I do first

From: Bob Shannon <bshannon_at_tiac.net>
Date: Sun Sep 29 10:13:00 2002

Thanks for catching my typo Joe. The MTBF (mean time between failures)
is greatly REDUCED by unsoldering chips, often very dramatically so.

Ever notice the soldering specifications for TTL devices, like 300
degrees C for not more than 10 seconds? This limitation is given for
the parts to meet their rated MTBF, not because 300 degrees C for 11
seconds will destroy the parts right away.

Resolder the parts, and you may be throwing away well over half their
service life. Clearly not a professional way to restore a machine. For
some repairs, we have no other option, but melting solder is a last resort.


Joe wrote:

>At 10:38 PM 9/28/02 -0400, you wrote:
>
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>>If you think this does the least dammage, your grossly in error. As a
>>test engineer, I can direct you to any number
>>of volumes that will show you the dramatic increase in MTBF
>>
>
> I think you mean dramatic DECREASE in MTBF. But I doubt many people on this list even truely understand what MTBF is. I worked in reliablility, logisitics and maintainablity so I'm prpobably one of the few that would catch this.
>
> Joe
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> for
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>>resoldered parts. This is known, for-sure dammage, not some risk of
>>dammage from a theoretical regulator failure.
>>
>>Care to defend this position?
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Received on Sun Sep 29 2002 - 10:13:00 BST