Antique Sound Labs Monoblocks stopped working

[bigthinker]

Hello.
I have a pair of ASL AQ-1006/845 Antique Sound Labs monoblocks and both died at the same time. I replaced the blown fuse and upon power on, they come on for 1-sec then shut back off - it blows the fuse. I don't smell anything burning. Roscoe suggested I post this to see if anyone wants to replaced whatever is failed. I'm in Bowie Md, so someone local to the DMV would be great.

Patrick
301-213-5477

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[TubeDriver]

Both Monoblocks failed at the same time? What is the wall voltage? Did you replace or swap out tubes before this happened?

[bigthinker]

Both mono blocks failed at the same time. I have taken out all of the tubes and replaced the blown fuse and upon power on it does the same thing. In short, it blows fuses whether it has tubes in or not.

[bigthinker]

The wall voltage is 120v. I have used the wall socket since then for other items (including amps) without a problem. They blew upon turn on vs. playing and suddenly shut off. I did not replace the tubes prior to this. They are they same/original tubes and power cables

Thanks

[Guy]

Hey, BigThinker, good to meet you!

Have the amps been used recently, or have the been out of service for months so the power-supply capacitors may need to be reformed?

Also: DBerning wrote in the Project Discussion: My Dead Dynaco ST-70 thread:

A good cheap tool useful for testing amps where a power problem may exist is to make up a fixture that has a light bulb such that the amp can be powered up with the light bulb in series with the power. A lamp with one of the power conductors is cut and a male AC connector bridges the two ends of the cut wire serves as the socket to plug the amp under test into. This is also useful for reforming capacitors in amps that have not been powered up in a long time. IF the lamp comes on very bright there is a short in the amp's power supply or transformer. If the lamp dims shortly after turning on, this usually indicates that things are OK to remove the lamp and plug the amp directly into the wall outlet. Do NOT do this with switching power supplies. Typically I use a 100-watt lamp.

[Guy]

There is a 0.1u mfd capacitor across the primary that could be shorted. If it's okay, you may want to start disconnecting one lead from each secondary until you find the portion that is screaming for current.

[TubeDriver]

There is a 0.1u mfd capacitor across the primary that could be shorted. If it's okay, you may want to start disconnecting one lead from each secondary until you find the portion that is screaming for current.

this^^^^

[Roscoe Primrose]

How long after the last time they worked did they fail? Had they sat for an extended period of time?

Roscoe

[bigthinker]

They have not been siting. They were working 1-2 days prior to failing. They were plugged into the wall. They longest duration of off/idle was about 48 hours.

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[TubeDriver]

It is odd that monoblocks would fail at the same time. I wonder about a power surge that shorted a small cap across H and Neutral or maybe fried the SS rectification?