CJ PF-2

[Pietro]

My pf-2 1/4 amp fuse blew off. I replaced it with a .5 amp fuse, only fuse available. The unit will not power up. did some voltage testing and I get 65v ac every where even on the positive side of the RCAs outputs. Can someone tell me the output voltage of the transformer. I have filling my is damaged.

[AnotherJohnson]

Not a good idea to double the fuse rating. If there is a short, it may blow a resistor or worse if a double value fuse is used.

Aside from that general observation, I agree with your feeling that there is damage … there was already an issue when the fuse blew. Now it may be more extensive.

Best of luck with the troubleshooting and repair. Be careful … there are potentially lethal voltages present, even when the unit is unplugged. If you were comfortable using a double value fuse, the safe repair may be beyond your skill set. Be careful.

[admin]

Agree with AJ. Do not change the fuse (especially going with a higher amp setting. Remember, the idea is that if there is a problem, you want to damage the fuse, not the rest of the components. Blowing fuses is a sign of a problem somewhere else in the circuit.

Unfortunately we don't have the PF2 schematic in our database so that is not going to be too much help.

[AnotherJohnson]

From the owners manual

Fuse
The AC line is fused to protect the PF2’s transformer. This fuse will not fail in normal operation. Failure of the fuse is a symptom of a more serious problem, indicating the need for qualified service. In no event should the fuse be replaced with a fuse of different type or rating than that supplied by the factory. The PF2/2L uses a 1/4 amp 3AG fast-blow fuse (1/8 amp 3AG fast-blow for 220V operation).

[AnotherJohnson]

FWIW, the owner’s manual is available for free download on the CJ website under the Vintage Products heading. It gives more info than a typical CJ manual, but it is not a substitute for a schematic.

[Pietro]

if anyone has a working CJ pf-2. can you measure the two voltage outputs from the transformer. Thanks

[roberto]

Hola Pietro,

Your measuring tells me that you have a missing ground somewhere. If you are using the chassis as ground, it might be isolated. Use the ground of the RCAs connector and do the measurements from there. Or, look at the foil of the printed circuit board, and use it from there.

Look where the bridge diodes are for the power supply. There are usually two or four regulated power supplies. Find the common O volts and from there you can do your measurements.

[roberto]

For common ground, the RCAs the negative should be with the chassis, if not, the chassis is isolated from the circuit, and should be keep it that way.

[Pietro]

I found a .5mf 100v cap that is damaged. Where is the best place to buy a replacement?

[admin]

If you want an original part it would be from CJ. However, I do not think they sell parts so you would have to send the unit in for repair. Otherwise, you are looking at after market caps.