Old Muntz TV for sale Locally to me, Should I pick it up?

[Electronic M]

Disclaimer: the component designators in the attachment are fuzzy and I may not have read them correctly.

Procedure: disconnect C1a positive and L1 from pin 2 of 5U4. Measure resistance to ground at pin 2 if the resistance is that specified in the service literature or higher then the shot is not in the tube or power transformer (but if it meaures well below spec resistance spec the tube socket and or power transformer are prime suspects).

If you cleared the power transformer of suspicion next disconnect L1, R95, C2b, focus control, and focus coil from each other. Check resistance of C1a, C1b, and both wires of L1 to ground...if any of them measures less than 1M to ground replace the part that has low resistance.

Check R95, focus pot, and focus coil to ground. If R95 checks lower than 100k to ground you may need to check the circus it feeds off the image you attached. If focus coil checks under 100k to ground unhook the other focus coil lead and measure each lead to ground if still low replace focus coil. If focus pot tests under 100k to ground disconnect it's terminals from circuit and measure from each to ground. If still too low pot is defective.
Also disconnect the positive of C1c and measure it's resistance to ground. Do the same for R94...if you still haven't found the short check the items off the attached image that the B+ drives.

Methodically divide and conquer...er um I mean measure till you find your shorted part(s). Replace culprit part(s) remeasure, reconnect all disconnected connections, remeasure to be sure the short is gone, and then power up if all now checks good (use a variac and or dim bulb tester if you have one just in case something is still wrong).

[vortalexfan]

Originally Posted by Electronic M

Disclaimer: the component designators in the attachment are fuzzy and I may not have read them correctly.

Procedure: disconnect C1a positive and L1 from pin 2 of 5U4. Measure resistance to ground at pin 2 if the resistance is that specified in the service literature or higher then the shot is not in the tube or power transformer (but if it meaures well below spec resistance spec the tube socket and or power transformer are prime suspects).

If you cleared the power transformer of suspicion next disconnect L1, R95, C2b, focus control, and focus coil from each other. Check resistance of C1a, C1b, and both wires of L1 to ground...if any of them measures less than 1M to ground replace the part that has low resistance.

Check R95, focus pot, and focus coil to ground. If R95 checks lower than 100k to ground you may need to check the circus it feeds off the image you attached. If focus coil checks under 100k to ground unhook the other focus coil lead and measure each lead to ground if still low replace focus coil. If focus pot tests under 100k to ground disconnect it's terminals from circuit and measure from each to ground. If still too low pot is defective.
Also disconnect the positive of C1c and measure it's resistance to ground. Do the same for R94...if you still haven't found the short check the items off the attached image that the B+ drives.

Methodically divide and conquer...er um I mean measure till you find your shorted part(s). Replace culprit part(s) remeasure, reconnect all disconnected connections, remeasure to be sure the short is gone, and then power up if all now checks good (use a variac and or dim bulb tester if you have one just in case something is still wrong).

Sorry about the fuzzy diagram the Sam's Folder came to me that way when I downloaded it from the Sam's website.

I'll definitely check those things out for sure.

[old_coot88]

Originally Posted by vortalexfan

I'll definitely check those things out for sure.

But by all means start with this from Electronic M:

Procedure: disconnect C1a positive and L1 from pin 2 of 5U4. Measure resistance to ground at pin 2 if the resistance is that specified in the service literature or higher then the shot is not in the tube or power transformer (but if it meaures well below spec resistance spec the tube socket and or power transformer are prime suspects).

With C1a+ and L1 disconnected from pin 2, you should read infinite resistance (open circuit) from pin 2 to ground. If so, that eliminates 5U4 socket and xfmr as suspects. Then proceed 'downstream' per Electronic M's directions.