Crate Palomino V32 Blowing Fuses

[luismetaliv]

Hi People!

I have a Crate Palomino V32 that i was playing for a little bit. Everything was going well, until one day the main (only) fuse blew up. No weird noises, no big sparks, no nothing, just blew up. I purchases a little box of fuses and replaced it and blew as soon as I turned the power switch on.

I started looking at the board (i'm handy with electronics), and I thought the filter caps could be bad, since the top on the two of them were bulging. Anyways, I followed a process of elimination

• I unplugged all the tubes: fuse blown.
• I unplugged all the leads coming out of the PT. Fuse was good.
• I started plugging in the leads of the PT on the board, one by one, and turned the power on for each lead connected. The fuse was good for connectors J29 and J24, but when I connect J25 and 26, the fuse blows.

So, I thought C19 was bad since the top was bulgy. I went and replaced the C19 and C16 caps (both were bulgy)- Don't worry, I discharged them before doing anything.

To my surprise, when I connected the amp. Fuse blew again.

What else could it be? could I have a bad PT now? Could it be the resistor in parallel with C19? or any other component on that rectifier circuit?

By the way, I took the old caps to a friend who’s got a capacitance meter....and they were not bad :/

[Chuck H]

Hard to imagine a failed 1N4007 but it does happen. Test the diodes. And...

I assume when you plugged in the HV secondary and the fuse blew it was with the standby switch open? If it was inadvertently closed then everything upstream of the switch is also suspect.

Otherwise a possible short. Those amps take a lot of physical stress beacuse of heat and how they're constructed.

[TomCarlos]

Does the Power Transformer use connectors to attach to the main PC Board? How about disconnecting these connectors and removing all tubes. Turn on the power. Do you still blow the fuse? If yes, you have a PT problem. If no, connect J24 (the 6.3vac circuit). Everything ok? Then connect the high voltage jumpers. Does the fuse continue to blow?

And to save fuses, do you have a bulb limiter you can use during testing?

[Jon Snell]

Check C32, 33, 33 & C34 then check the 1N4007s. The fuse blows in Standby I presume; (No HT to J40).
If you disconnect J40 and have it in Standby, it can only be the diodes or capacitors mentioned. C19 is the correct polarity? The print on the board is sometimes incorrect, check polarity if unsure without C19 fitted.