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Bad TI IC sockets: Difference between revisions
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are non-RoHS since the solder-tail (PCB end) is also lead-tin plated. | are non-RoHS since the solder-tail (PCB end) is also lead-tin plated. | ||
Former Tek Engineer Jim Mauck says: | |||
<blockquote> | |||
I noticed your article on bad Texas Instruments IC sockets. I literally | |||
replaced 100's of those sockets. I believe TI's part number was C95. They | |||
were used throughout Tek at the time but they do not always cause an issue. | |||
They didn't have a gas-tight contact with the IC pin and they would oxidize | |||
over time and develop a resistive connection. This wasn't necessarily a | |||
problem for low current applications but it was death to any ECL circuits. | |||
Unfortunately ECL was used extensively in logic analyzers. There were very | |||
high failure rates for the 7D01, DF1, and DF2 and eventually Tek had an | |||
unpublicized board exchange program for those instruments. Service | |||
technicians could replace the boards but there was no official modification | |||
kit or customer notification. | |||
</blockquote> | |||
<blockquote> | |||
Failures due to these sockets were typically intermittent. A classic | |||
indicator of bad sockets was having the problem disappear if you wiggled all | |||
of the ICs in the socket. Doing that scraped off some of the oxidation and | |||
the instrument would work for another month or so until the contacts were | |||
again oxidized. The problem was exacerbated in some cases because Tek was | |||
using ICs with tinned leads intended to be soldered to the circuit board - | |||
not socketed. I never saw any problems in high current applications when the | |||
leads were gold plated. | |||
</blockquote> | |||
[[Category:Repair issues]] | [[Category:Repair issues]] | ||