EEVblog Electronics Community Forum
Electronics => Repair => Topic started by: NoisyBoy on December 23, 2019, 04:47:43 am
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Hi,
The slide switches at the back of my Agilent E3615A (which selects local or remote CV, CC settings) has developed a very high resistance and affecting the operation of the power supply. It is Agilent part number 3101-3237, which is obsolete and no longer available from Keysight.
Does anyone know if there's a substitute for this switch? They are labeled S1- S4 in the PCB next to the rear panel.
Update:
For other E3615A owners, I have had this supply for nearly 7 years since I bought it new. I have always run it in Local mode, and the slide switches have always been in the up position since new. I played with the switches last night, and the output drop to 0V. The service manual troubleshooting workflow never suspected these switches, and I end up ordering a number of spare parts. Tonight, when I put the DMM across these switches, I found out that even with the switch back in the up position, the switch has either go into open circuit, or with nearly 100K of resistance. Clearly, something oxidized within it over time and created the bad connection. The failure existed in three of six contacts.
After flipping it up and down a hundred times, two switches fixed themselves, but one maintained 80K Ohm of resistance. These switches are no longer made by Keysight, and I have not been able to find exact replacement. So in desperation, I flooded it with deox through the slider opening. After a couple hundred repeated up and down, the resistance dropped back to less than 0.1 Ohm. Now the power supply is back in perfect working condition.
So, if your supply works fine, done touch those switches. Otherwise, you may have to do hundreds of finger exercise to get it back up and running.
Now, I have a bunch of spare parts on the way. I have plenty of extra parts to repair it in the future :-)
I hope this post can help others with similar problems in the future.
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Thanks for posting.