29 Sep
2002
29 Sep
'02
3:13 a.m.
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:
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
for
resoldered parts. This is known, for-sure
dammage, not some risk of
dammage from a theoretical regulator failure.
Care to defend this position?