Silvertone 1482 Fuse Troubleshooter help

[yes2matt]

Hi, this is my first post after lots of lurking and googling, and I'm still a tube rookie, but I could use a little good advice to save a lot of solder.

I got a Silvertone 1482 in mint condition from a friend. I was even more of a rookie at the time, and plugged it into the wall and powered it up after sitting in an attic for 40 yrs, instead of using a variac 🙁

So it worked fine for about 15 minutes then the fuse blows. I replaced the fuse again and it blew after about 10 minutes again.

So then I started reading and googling 🙂

I pulled out all the tubes, turned it on, it will sit with power for a long time. Then added rectifier, then preamp, then power tubes.

Currently it will run fine with either power tube (6V6) but not with both. If I have it powered and both tubes installed the fuse blows after some minutes.

What is your advice for my first replacement? My instinct is power tubes, but they each seem to work ok alone... what else should I consider?

Thanks for your patience w/ a beginner 🙂

 

[famousmockingbird]

If you have and can wield a multimeter it will be easier to help you. Also does it have original caps and valves etc?

i actually have the same amp on the bench right now that is in need of some tlc.

 

[indianajo]

Electrolytic caps are aluminum cans full of slime, sealed with rubber. the rubber deteriorates from the oxygen in the air, sitting or running. More when they are running. Many people find old consumer electronics run fine at the resale shop, then blow 4-80 hours later as the water evaporates out past the cracked rubber seal.
I don't measure electrolytic capacitors, except with a calender, YY<1992 is a potential problem.
Measure all metal below the chassis <25 VDC before you touch it. Don't use more than one hand, use a clip lead on the negative. For details on how to replace can caps cheaply with radial lead caps, which can be rated at hours life of 10000, see this thread www.diyaudio.com/forums/tubes-valves/201265-vintage-magnavox-tube-amp-3.html

 

[yes2matt]

If you have and can wield a multimeter it will be easier to help you. Also does it have original caps and valves etc?

i actually have the same amp on the bench right now that is in need of some tlc.

Yes I have one. I'm good w/ electrical stuff and some electronics, tube amplification is a frontier for me 🙂

What should I test?

Everything is stock, like a time machine, just a little attic dust, now clean.

 

[famousmockingbird]

Well the old 6v6's could be about dead and pulling excessive current and popping the fuse. I would stick a known good pair of 6v6's in and if the fuse doesn't pop measure from one of the 6v6's pin 8 to ground, it should read around 15v.

I agree with the above statement about replacing the electrolytics in that amp. There are only 4 I think.

 

[yes2matt]

Thanks for the help so far. I've got new caps on order from Newark, newish ("tested") 6V6's on order off the 'bay. There's this funky cap in it (like a multi-tap transformer) that has three values, 20/10/5 uf /450v. I ordered a 22uf, a 10uf, and a 4.7uf. << the lower capacitance: is that OK? or will it cause trouble? I could have gotten the Sprague spec'd at 5, for the price of the rest of the order 🙂

The others were easy to find matches for.

So here's to waiting on the UPS man to bring me my goodies... what can brown do for you?

 

[DigitalJunkie]

Those cap values are fine. Are the new caps also rated 450V,I hope?