Good day to all. A quick question for those of you with more experience than I. I recently pulled the outputs from and old HK amps and noted as I was cleaning them up that my nice clean paper towel was turning black. No issues with the case itself, but the pins were something other than clean. Pinching a pin between my index finger and thumb, it took better than 5-6 swipes before I could see shiny pins and no more residue on the piece of paper towel. So, Is this corrosion? It
seemed somewhat greasy and they were mounted with Mica/paste (paste was white as the day it was applied). Can I assume the sockets are in the same shape (probable)? Lastly, when I either clean or replace the sockets should I apply a light film of dielectric grease on the pins prior to remounting the tranny's or leave them dry. Heretofore, I've always left them dry.
Thank you in advance for any/all sage advice. Have a good day, Stay safe.
seemed somewhat greasy and they were mounted with Mica/paste (paste was white as the day it was applied). Can I assume the sockets are in the same shape (probable)? Lastly, when I either clean or replace the sockets should I apply a light film of dielectric grease on the pins prior to remounting the tranny's or leave them dry. Heretofore, I've always left them dry.
Thank you in advance for any/all sage advice. Have a good day, Stay safe.
Sockets are obsolete. Glad yours lasted until now. I would clean the pins with steel wool, then paper towel with alcohol. Then replace the sockets with heat sink and insulators, then solder the pins with wires. If collectors are not shorted to the heat sink, you can use insulators on the screws that come with the mica washer kits. Then use ring terminals on the collector screws to attach the wires.
Interestingly enough the silver oxide conducts better than pure silver! However if there is contamination from coal fired exhaust, you can get silver sulphate which does not conduct.
Thanks for the responses gentlemen. Admittedly, I wasn't expecting ditch the sockets, but then again at 67 doubt I'll be going back into this thing again. Cheers.
@wiseoldtech
I noticed you "liked" the post re sockets being obsolete and I'm curious - with your experience servicing equipment, I wondered where the problems you see tend to be found. My guess would be in higher power usage situations - pass transistors, etc. - and not signal level socketed components. Other than the early TI IC socket failures though, which were the results of a fundamentally bad design, that has been my experience - but my experience is typically with lab grade test equipment, not commercial products, so I am curious as to how widespread the problem is. For what it's worth, I agree with @indianajo in hardwiring power devices - although i would say that are much better choices than steel wool to clean electronics.
Hal
I noticed you "liked" the post re sockets being obsolete and I'm curious - with your experience servicing equipment, I wondered where the problems you see tend to be found. My guess would be in higher power usage situations - pass transistors, etc. - and not signal level socketed components. Other than the early TI IC socket failures though, which were the results of a fundamentally bad design, that has been my experience - but my experience is typically with lab grade test equipment, not commercial products, so I am curious as to how widespread the problem is. For what it's worth, I agree with @indianajo in hardwiring power devices - although i would say that are much better choices than steel wool to clean electronics.
Hal
TO3 sockets were part of the manufacturing process for decades, but due to the quality of some, caused issues in some of the equipment that landed on my bench.
Some from thermal-cycling, others from corrosion build-up.
The consumer industry was aware of this too, and started hard-wiring those TO3's.
In some cases, the sockets were still used, but also had the transistor pins soldered to the socket.
It made servicing more difficult, but amp failures decreased.
TO3 pins that need cleaning are best done with some emery paper.
Face it, good old soldering of components is the most reliable way to build things if any long-term reliability is to be expected.
However, as with anything, the manufacturing process of anything is fundamentally important.
For instance, the "wave soldering" of boards that became the norm had its own problems...
If the process was not monitored carefully, and checked by the Quality Control department, issues could arise with poor solder joints - also due to thermal cycling.
I can honestly say that over the decades in the shop, a substantial part of my time was spent with magnifying goggles on, tracing out and re-soldering those intermittent "ring joints".
My colleagues in the service business all coined a phrase that we gave to poor wave soldering and failures...
We called them "Monday or Friday" units..... joking that if manufactured on those days it was possible that the factory workers weren't alert yet on Mondays, or hung over, or in a hurry to get home and cash their paychecks on Fridays.
Another thing that annoys me and other techs is the use of lead-free solder.
That crap was implimented to appease the annoying "save the planet" crowd.
Makes servicing difficult, and is just as prone to failures.
We stick to good old Kessler 60/40 solder.
Some from thermal-cycling, others from corrosion build-up.
The consumer industry was aware of this too, and started hard-wiring those TO3's.
In some cases, the sockets were still used, but also had the transistor pins soldered to the socket.
It made servicing more difficult, but amp failures decreased.
TO3 pins that need cleaning are best done with some emery paper.
Face it, good old soldering of components is the most reliable way to build things if any long-term reliability is to be expected.
However, as with anything, the manufacturing process of anything is fundamentally important.
For instance, the "wave soldering" of boards that became the norm had its own problems...
If the process was not monitored carefully, and checked by the Quality Control department, issues could arise with poor solder joints - also due to thermal cycling.
I can honestly say that over the decades in the shop, a substantial part of my time was spent with magnifying goggles on, tracing out and re-soldering those intermittent "ring joints".
My colleagues in the service business all coined a phrase that we gave to poor wave soldering and failures...
We called them "Monday or Friday" units..... joking that if manufactured on those days it was possible that the factory workers weren't alert yet on Mondays, or hung over, or in a hurry to get home and cash their paychecks on Fridays.
Another thing that annoys me and other techs is the use of lead-free solder.
That crap was implimented to appease the annoying "save the planet" crowd.
Makes servicing difficult, and is just as prone to failures.
We stick to good old Kessler 60/40 solder.
"Another thing that annoys me and other techs is the use of lead-free solder.
That crap was implimented to appease the annoying "save the planet" crowd.
Makes servicing difficult, and is just as prone to failures.
We stick to good old Kessler 60/40 solder."
+442000 !!!
That crap was implimented to appease the annoying "save the planet" crowd.
Makes servicing difficult, and is just as prone to failures.
We stick to good old Kessler 60/40 solder."
+442000 !!!