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Topic: Calling all Peavey techs |
Michael Haselman
From:
St. Paul
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Posted 5 Jul 2008 6:10 pm |
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I've got a 20-year-old Triumph 60. I replaced a faulty on/off switch. Now the power light is on, the foot pedal lights go on, but the tubes do not light up, power or preamp. I can see 5 fuses, and they all check good to me. (zero ohms resistance) Is there some hidden fuses somewhere or is something else fried?
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Mullen RP D10, Peavey NV112, Hilton volume. Hound Dog reso. Piles of other stuff.
Last edited by Michael Haselman on 6 Jul 2008 7:10 am; edited 1 time in total |
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Dave Mudgett
From:
Central Pennsylvania and Gallatin, Tennessee
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Posted 5 Jul 2008 7:18 pm
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I'm not exactly a Peavey tech, but when you say "(Ohm at infinite)", do you mean the fuses read infinite Ohms, which means they're open? Open fuse means it's bad. A good fuse should read basically zero Ohms. I see only 5 fuses on the schematic at schematic heaven, which you should get if you don't have it. If any of them read infinite Ohms, then replace it with one of the same value - not larger - but if something else caused it to blow, expect it may happen again.
The next thing I would think about is what's going on with your power switch. Perhaps other stuff was wrong before you fixed it, or perhaps something went wrong with your repair.
Next, I would probably look at the power supply. Possible problems could be the power transformer, diode bridge rectifiers, and filter capacitors. Since the tubes aren't lighting up, I would first look at the filament portion of the power transformer and the rest of the filament supply. There's a diode bridge rectifier and a few capacitors and resistors, plus a hum adjust pot. According to the schematic, the fuse for that subsystem is F5.
Of course, unless you know about tube amp electronics, you should just get this to a qualified tech. You can kill yourself with the high voltages or mess up the amp worse if you don't know what you're doing. |
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Ken Fox
From:
Nashville GA USA
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Posted 6 Jul 2008 6:21 am
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There are two supplies for the heater circuit, see the drawing below. Both have fuse 5 involved. The DC supply is for the first 3 preamp tubes. The schematic covers both the Triumph 60 and 120. You will have two less tubes than shown.
The fact that all your tubes are involved would tend to make me believe a fuse or transformer is suspect.
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Michael Haselman
From:
St. Paul
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Posted 6 Jul 2008 11:46 am
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Sorry, I meant zero ohms. I pulled and checked them again, and the fuses are OK, so I guess it's more serious. I've had this for 20 years, and it's a spare, so I don't know how far I want to go into it. Are transformers hard to replace and how could I check to see if one is fried or not? If it takes more than a multimeter, I'll either junk it or take it somewhere, but it seems replacing a transformer shouldn't be that difficult.
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Mullen RP D10, Peavey NV112, Hilton volume. Hound Dog reso. Piles of other stuff. |
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Ken Fox
From:
Nashville GA USA
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Posted 6 Jul 2008 11:50 am
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I would pack it up )the chassis and tubes) and send it to the Peavey repair center.
PEAVEY SERVICE CENTER
412 HWY. 11 & 80 EAST
MERIDIAN, MS 39301
ATTN: REPAIR
Send the tubes with it so they can be tested (packed separately of course)
A failed power tube will often damage the heater circuit. Seen it take out the balance pot on many a Fender amp in the past. |
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