Mep 003a voltage hunting

[Speddmon]

Capacitors can dry up or more commonly, bulge. Either way, they lose capacity . Really, think of them as surge chambers. Piece of cake to replace all, it takes too long to test each one.

Other things are pots burning the wiper contact area. Also easy to test.

But testing the entire unit may be difficult. I don't have cross-reference on the -24Ps between the 002a and 003a so I would have to borrow a genset if they aren't the same.

I think I could sweet-talk mk into loaning his. Takes too much time to make a test bench for a one-off.

The VR boards on the MEP-003a and 002a are the same. I have repaired one before, and also built the testing circuit in the TM. The test circuit was easy to build. And the board was easy to repair. The worst part of the job was getting the epoxy off of the components you want to test and replace.

 

[Keith_J]

Here are some pics. The new board is installed in the background. Also included is the generator that I just mounted on a trailer that my brother made.

Sweet. That is easily servicable layout. We have to repair as much as possible in this avocation, spares can be pricey.

Now I do have access to an oscilloscope but no bridge. I might be able to kludge together a testing apparatus for capacitors. Of course that would require component isolation but the traces on the PCB make that easy. Just two layers, nothing masked.

Nice trailer. I would hang reflectors on the generator when on the road, people just don't look. I bought a trailer earlier this year, a flat bed 5x8' and not 300 yards after pulling out of the dealer's lot, it was rear-ended by a motorist who just wasn't paying attention. No damage, just frayed nerves.

 

[Keith_J]

I had the same problem with my 002a yesterday. The variable resistor on the control panel wasn't properly varying due to dirt.

The aluminum case is crimped over the Garolite (phenolic-fiberglass) backing and easily uncrimped with pliers. remove the nut on the front and clean it with tuner cleaner (do they still make that?). Test with voltmeter to make sure it varies from 0-1000 ohms smoothly.

Sure, you could buy a new one. But if you can fix it, why not?