# Amp dead



## guitarman2 (Aug 25, 2006)

I was just playing my guitar through my 67 fender pro reverb when I started to lose volume. Then it went fuzzy and distorted. Then the amp went dead. I smelled what might have been something burning but it was so faint wasn't sure if it was just the amp hot. I took the fuse out and sure enough it was blown. I had a few fuses on hand so I figured I'd plug one in to see if it would come on. I expected it would come on for a split second and blow as I suspect the rec tube is no good. I insert the fuse and flip the switch but I didn't see the jewel light come on at all. I try a second fuse and it come on just for a millisecond, hardly even noticeable. So maybe the first fuse blew so fast the jewel light didn't come on at all. I The original fuse was black so it definitely blew. The 2 fuses I put in are definitely blown to. So does anyone think this could be anything other than the rec tube?
I guess I'll have to order a new rectifier and get some fuses. I wonder if the fuses I have on hand are even the right ones. The amp calls for 2 amp slow blo. The fuses I have, on the package says, 1A, 2A, 3A, 250V. On the head of the fuse it says 3A 250V. I think I picked them up at Canadian tire.
Guess I'll order a rectifier and see if thats it.
Anyone have a good recommendation from the Tube Store?


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## Lunnen (Apr 28, 2010)

Hey there,

Not sure if it's the issue but I recently lost my power switch on my Silverface Deluxe Reverb. Albeit, the fuse did not blow but there were contact issues in the switch. The process of failure was very similar to your experience. I similarly smelled the burn which turned out to be the switch. Replace the power switch (nothing wrong with the standby) and all is well. May be worth checking. I pulled the chassis and could see the burn mark on the switch before I took it to my amp tech. Good luck! Hopefully, it's something minor.


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## Paul Running (Apr 12, 2020)

I believe that it is more than a fuse issue. Has the amp been upgraded to 3-wire mains?
Are you familiar with the smell of a burnt transformer?...identify where the odour is originating.
Fuses are very reliable...it's blowing for a reason other than it being faulty.


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## oldjoat (Apr 4, 2019)

1st ... buy more of the right fuses
2nd ... flip the unit and *look* inside for burned wires / resistors / leaking or exploded caps ...
..........obvious stuff. WHILE UNPLUGGED
3 ...... failing that , get it to a tech ... there's dangerous voltages left inside (even after unplugging) 
don't risk your life


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## Chito (Feb 17, 2006)

Yes about the transformer. Once you smell a burnt transformer, you never forget it. LOL Happened to my 40 year old princeton. The smell of that transformer stayed in my basement for at least a week. 
If it was me and you're probably more knowledgeable than me when it comes to electronics, I'd bring it to my tech.


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## Griff (Sep 7, 2016)

Could be a recto. Was it making any noise itself prior to the amp failing? Any GZ34 works. L&M should stock a few for $40ish.

That said, it could be a lot of other things. Agreed you should have the correct fuse in there. Has this amp had a cap job? Filter caps and bias cap mainly.


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## Lincoln (Jun 2, 2008)

Pull all the tubes, if it still blows a fuse.......there's trouble.


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## Chito (Feb 17, 2006)

I had a problem with my DRRI before. I was in a gig doing sound check. Amp blows a fuse. Replaced the fuse and rectifier tube after a bit it started to make noise. Long story short it stayed with the tech for at least 2 months because it became an intermittent problem which was hard to recreate. In the end, it was the V1 tube which was what was left from the tubes that were originally there. 
And this is why I suggest bringing it to a tech coz a burnt fuse usually tells you there is something going on . And that could practically be anything.


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## numb41 (Jul 13, 2009)

No offence, but it’s clear that you don’t know what you’re doing. I would take it to someone who knows electrical theory and works on amps.


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## guitarman2 (Aug 25, 2006)

As I said, I'm not really sure if I smelled anything. It just seemed like it when I looked in to the back of the amp. There was definitely no strong smell or smoke. I've seen smoke come from an amp before when I blew a resistor which took out a power tube. Could be it was just hot. I've had problems with tube amps before where the fuse kept blowing (Blew 2 more) and in those cases I replaced the rectifier and all was well. I've ordered a pair of 6L6 and a rec from the tube store. When I get them I'll put them in along with a new fuse. If I still have issues I'll get it in to a tech ASAP.


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## jb welder (Sep 14, 2010)

Sounds like that fuse pack from C-tire was an assortment. Use only the correct 2A slow blow.
The ones you had were probably fast blow so that may have saved you from extra damage using a 3A in there.
Like @Lincoln said, try it with all tubes removed. If it blows another one with the tubes out, it is a serious issue.


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## nonreverb (Sep 19, 2006)

+1 on removing the tubes. Could be the rectifier, a power tube.....or the power transformer. One other question if I may...Have you recently replaced the pilot light or have touched the light for any reason? if so, there's always the possibility the bayonet mount supply tab(s) have touched the chassis as they are usually loose and will move easily if twisted. I've seen them where they intermittently short due to them riding close to the chassis. Hopefully, it's just a rectifier.


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## guitarman2 (Aug 25, 2006)

By removing all the tubes do you mean just the power tubes and rectifier or do I need to remove the preamp tubes as well? It won't hurt the amp turning it on with tube out?


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## Lincoln (Jun 2, 2008)

guitarman2 said:


> By removing all the tubes do you mean just the power tubes and rectifier or do I need to remove the preamp tubes as well? It won't hurt the amp turning it on with tube out?


The rectifier and power tubes are the main ones, and commonly the ones that fail. But to be sure, remove the pre-amp tubes also if you can. It does not hurt the amp in any way to turn it on without tubes. 

When I build a new amp, the first time I turn it on and check voltages is without any tubes in it. Then I'll put in the rectifier tube (if equipped) and check it over again. Then finally add all the tubes.


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## Griff (Sep 7, 2016)

A lightbulb limiter, which is a very easy home build with parts just from the Home Depot, would also save a lot of fuses.


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## Latole (Aug 11, 2020)

Most of the time when fuse blow, it is power Output Tubes failure.
1- Put a 3 amp fast blow fuse if you don't have 2 A slow blow.
2- Remove Power Output Tubes.
3- Power amp ON.
If fuse did not blow it look a power tube failure
Replace them and *adjust bias.*
Power tube issue may burn some resistors too.

Best is to bring amp to a good amp tech

If fuse blow;
1-Remove rectifier tube.
If fuse did not blow ; rectifier or /and power suply issue ; filter caps ?
If filters caps are original, you must replace all them with new one ; I'll use F & T brand.
Don't forget Bias circuit filter cap


IMO Canadian Tire may not have this low power fuse. They sell car's fuse wich are more poerfull ; 10A and more

Pro-Reverb main circuit ;


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## Latole (Aug 11, 2020)

Griff said:


> A lightbulb limiter, which is a very easy home build with parts just from the Home Depot, would also save a lot of fuses.


Lignt bulb limiter need 75/ 100 watts incandescent light bulb, not easy to find today .
I bought a large stock.....


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## StevieMac (Mar 4, 2006)

I sincerely hope your troubleshooting and DIY efforts pay off. Someone I know did _exactly _what you're doing (replacing fuses/tubes etc) with their vintage amp and ultimately killed the PT, which then needed replacing. That was a costly mistake to fix and the value of his amp took a huge hit. He _really _wishes he had just paid a good tech the 1 hr bench rate to determine the source issue. Everyone assesses risk differently however and perhaps your gamble will pay off.


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## Budda (May 29, 2007)

Worth noting an amp tech may have been able to get the parts a little cheaper as well.

Hopefully it's relatively painless to fix.

I remember nearly needing an OT, that was unpleasant.


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## ampaholic (Sep 19, 2006)

Lincoln said:


> Pull all the tubes, if it still blows a fuse.......there's trouble.


+1
This is so easy I can't imagine wasting time thinking about doing anything else.


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## guitarman2 (Aug 25, 2006)

StevieMac said:


> I sincerely hope your troubleshooting and DIY efforts pay off. Someone I know did _exactly _what you're doing (replacing fuses/tubes etc) with their vintage amp and ultimately killed the PT, which then needed replacing. That was a costly mistake to fix and the value of his amp took a huge hit. He _really _wishes he had just paid a good tech the 1 hr bench rate to determine the source issue. Everyone assesses risk differently however and perhaps your gamble will pay off.



I may just take it in to Rich at Amps plus anyway as I'll need to get the new power tubes biased. I don't really care about the value so much. I am so in love with how this amp has sounded it will be with me forever. So changing a PT if that blew is not a big deal as long as it doesn't change what I've been hearing from this amp for the few months I've owned it.


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