I am feeling very stupid that I cant figure out a simple e-cap replacement. Starting on G.E model M-81 (Same as RCA mod. # 143) Power up carefully and works o.k. Replaced two e-caps very straight forward as to positive and ground are. Radio still works fine. Then there are two metal can e-caps next to each other. The schematics are horrible and impossible to read. I clipped the leads, soldered in new 10MFD caps and now nothing. I assumed the neg. goes to chassis since the metal cans are attached to the chassis. re-attached to old caps and radio works. I worked on this almost all night and gave up. I will go play with the granddaughters to recuperate and think about it. Hope someone can shed some light on this.
Thanks,
Jon.

Jon

Right, negatives go to chassis. Changing electrolytic caps shouldn't have stopped the radio. Even using different values.

http://www.nostalgiaair.org/PagesByModel/753/M0014753.pdf

Are you sure something else wasn't also in the cans? Chokes or other coils can be in a can.

Sometimes there are more than a couple wires going to electrolytic caps. Could one not be connected?

Norm

:I am feeling very stupid that I cant figure out a simple e-cap replacement. Starting on G.E model M-81 (Same as RCA mod. # 143) Power up carefully and works o.k. Replaced two e-caps very straight forward as to positive and ground are. Radio still works fine. Then there are two metal can e-caps next to each other. The schematics are horrible and impossible to read. I clipped the leads, soldered in new 10MFD caps and now nothing. I assumed the neg. goes to chassis since the metal cans are attached to the chassis. re-attached to old caps and radio works. I worked on this almost all night and gave up. I will go play with the granddaughters to recuperate and think about it. Hope someone can shed some light on this.
:Thanks,
:Jon.
:

The two 10 MFD capacitors are on each side of the field coil. It is possible there is a bad connection in the B+ path though this coil. Replace the two capacitors again. If no go, test the voltage going though the field coil back to the other capacitor. Sometimes an existing condition only shows up after moving wires or parts.

:The two 10 MFD capacitors are on each side of the field coil. It is possible there is a bad connection in the B+ path though this coil. Replace the two capacitors again. If no go, test the voltage going though the field coil back to the other capacitor. Sometimes an existing condition only shows up after moving wires or parts.

Warren / Norm,
Thanks for the advice. I re-attached everything back to where it was originaly and verified that the radio worked. I then subbed one cap and verified radio worked. Did the other and shazzam! It works. I had soldered one wire to the wrong cap-looks like I had shorted across the field coil. Now on to figuring out the other cap values-the caps are only marked with a part number that does not match anything on the schematic and the schematics are very hard to read. I have the sister set, the floor console equivilant to the RCA 262, it was called the "Bandmaster"-its a real monster chassis but sounds amazing.
Again thanks for the help,
Jon.
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