1981 Magnavox with a problem.

[Bill R]

Buy the way, is the fuse good on the power amplifier?

[Firebird]

I put a new one on even though it wasn't blown. I resoldered the whole chassis. That was how i got it to come back, that and replacing the HOT transistor as well as replacing the safety capacitor with a regular capacitor. I resoldered the motherboard, connectors and modules.

[holmesuser01]

Replaced the safety capacitor with a regular one? I'm not too keen on that. They are specific capacitors for the circuit.

[Bill R]

May not have been much choice but to use a regular capacitor. The original may very well be NLA. Usually not a problem if proper size and voltage caps are used. Since it is a safety componant, and I always try to avoid litigation, I would never do that on a customer set, but on my set I might if it was all I could get.

[Firebird]

I was told that if the original version failed it could destroy the picture tube.

[holmesuser01]

Originally Posted by Firebird

I was told that if the original version failed it could destroy the picture tube.

I've seen it snap the neck off of a 23" CRT.

Other than the updated versions of the safety capacitors, I've never had to replace one with anything else.

[Firebird]

T815-09

[Firebird]

I plugged it in today, took off the back to observe. I use a digital box now as we no longer use cable and the satellite does not have an rf connector. When i changed channel to one with a cartoon the picture started trying to unfold and became full width on the left. Still a quarter inch black band on the right.

[Firebird]

From looking around the net i have concluded that the problem is the Horizontal Oscillator module. Since no one seems to have one and i can not pin down the exact component, i will have to rebuild the module.

[holmesuser01]

Good luck with that.

[Firebird]

An odd film capacitor is near the horizontal hold driver. Numbers are M4/00 TRW 4700H. Does anyone know how to read this?

[Firebird]

I need more than luck. Some advice would be nice.

[Bill R]

Check the power supply voltages going to the module first. Low B+ may also be a problem. I would check the electolytics with an esr meter, but I dont recall problems with the other caps.

[Firebird]

Power supply is fine, electrolytics are all new. I am having trouble finding the film capacitors and transistors on the board.

[Firebird]

Horizontal oscillator module number is 703881-3 if anyone has one.