C70: Fuse Blew

[avionic]

.539 OL
OL .540
.541 OL
OL .541

Solder it back into circuit the same way it came out.

Good Job... It tests good..

 

[Gary D Olson]

Best thing about California is that it could sink into the ocean anytime. Hopefully we make it out first.

 

[Gary D Olson]

Solder it back into circuit the same way it came out.

Good Job... It tests good..

copy, and thanks.

 

[avionic]

When you get it soldered back in. Measure the resistance between pin1 of the rectifier and metal chassis ground. And pin 4 and chassis ground.

 

[Gary D Olson]

When you get it soldered back in. Measure the resistance between pin1 of the rectifier and metal chassis ground. And pin 4 and chassis ground.

OL on both.

Perhaps I should've mentioned, I haven't yet procured a replacement fuse. Closest I have in my tool box is 250v 3A.

 

[Gary D Olson]

Will try to get to home depot tonight. They have them.

 

[avionic]

In that same general area there is probably a lot of dried glue on the circuit board around those two large heatsinks. Scrape and chip it all away. Look for corrode/oxidized green component leads.That may have been in contact with that glue.

Closest I have in my tool box is 250v 3A

Way to large..Don't even think about it.

 

[avionic]

OL on both.

Did you do the Ω's check or Diode check ? Needs to be Ω's.

 

[avionic]

Will try to get to home depot tonight.

Pick up more than 1..

 

[Gary D Olson]

Did you do the Ω's check or Diode check ? Needs to be Ω's.

Sorry.

Ohms check reads:
OL
7.1

Now, off to HD to pickup more than one fuse.

 

[avionic]

7.1

Do not power up yet.

Thats and issue ie. short circuit.. Big time... Was it pin 1 or pin 4 ?

 

[avionic]

Remove the two large capacitors next to the transformer and heatsinks and re-measure that 7.1Ω pin.

 

[Gary D Olson]

Back with fuses.

Assuming pin 1 is on he beveled side, pin 4 is 7.1

 

[Gary D Olson]

Remove the two large capacitors next to the transformer and heatsinks and re-measure that 7.1Ω pin.

No change

 

[avionic]

OK.. Moving further down the line.from pin 4.

 

[Gary D Olson]

OK.. Moving further down the line.from pin 4.

3: 3.5
4: 3.5

 

[avionic]

TR547 needs to be removed. Its one of the two big heatsinked transistors.

 

[avionic]

3: 3.5
4: 3.5

Pins 2 and 3 are out of the picture. They are the AC side of the bridged rectifier. I am t-shooting the DC side of the rectifier.

 

[Gary D Olson]

TR547 needs to be removed. Its one of the two big heatsinked transistors.

Caramba. Is 547 the one closest to the back of the unit?

 

[Gary D Olson]

nevermind, it is...