"Internal fuse blown"

[martinrr]

On a 5150, how bad could an "internal fuse blow" be? Price? Damage?

 

Thanks. I know it's vague but whatever you know would be great!

[JamesPeters]

Fuses usually blow because tubes die.

Replace the tubes, replace the fuse, you're probably fine. Imagine the cost of a new set of tubes plus the minimum labor charge from a tech to replace the internal fuse.

[kannibul]

With my stuff, if I blow a fuse, I replace the fuse. If it blows again, I look into why.

My Orange is a good example of that - I popped one of the fuses for a pair of tubes during the Okie Ampfest a while back. I just replaced the fuse, and all was good.

Maybe 6 months later, I blew the HT fuse (internal) as well as the same fuse on the outside.

Replaced those and the tubes (since I noticed one tube didn't "look" right) and all is well.

I plugged that tube that didn't "look" right into my Octal High-Octane, and you should have seen the lightshow that tube gave. White-hot sparks... that tube was so toasted - lol.

[martinrr]

Well, I found some guy selling a 5150 for dirt cheap because it has an internal blown fuse, is there anything I should look for on it? Damage wise?

[JerryP]

Like James said, it's usually caused by tubes. The heater supply has a tendency to burn up the ribbon cable on the 5150's.
Jerry

[potaetoes]

Originally posted by martinrr Well, I found some guy selling a 5150 for dirt cheap because it has an internal blown fuse, is there anything I should look for on it? Damage wise?

 

 

heh... yes. in this case, everything should be checked.

 

i'd be highly suspicious. that's like selling a car cheap because one spark plug is bad.

[JamesPeters]

Originally posted by JerryP Like James said, it's usually caused by tubes. The heater supply has a tendency to burn up the ribbon cable on the 5150's. Jerry

Good call. I haven't serviced many of them but I've seen evidence of that in one of them at least. Anyway they do use good headers and connectors for those ribbon cables...I just wish the cables were a bit thicker and the wires weren't crimped into place.

Originally posted by potaetoes heh... yes. in this case, everything should be checked. i'd be highly suspicious. that's like selling a car cheap because one spark plug is bad.

Well, some people won't want to take the amp to a tech because they are worried they'll have to pay lots to fix it. I'd say it's 50/50 that it's just a minor issue, at least.

[potaetoes]

Originally posted by JamesPeters Well, some people won't want to take the amp to a tech because they are worried they'll have to pay lots to fix it. I'd say it's 50/50 that it's just a minor issue, at least.

 

 

yeah, but how does he know it's an internal fuse?

 

if he knows enough to know that's what it is, he knows enough to spend a quarter and replace it instead of dumping the amp for cheap... but for some reason, he hasn't done that. if he doesn't know enough to diagnose it himself, then a tech told him, in which case he would have already paid a bench charge to find out, and then it would have been another quarter for the tech to fix it. in either case, it should be easily fixed once it's identified - but it's not, and he's dumping it for cheap.

 

just seems likely that there's more to it that what the seller is saying... unless he's just a moron.

[martinrr]

I'm hoping he's a moron.

[JamesPeters]

He might very well be. He's essentially admitting he took the trouble to troubleshoot it but not bother replacing a fuse (as Potatoes said) or just plain lying in the hopes of selling the amp without having to get it fixed. It's very likely he doesn't know what's wrong and is saying it has a blown internal fuse as an excuse. All he really knows for sure is that the amp isn't working properly...beyond that, you're rolling the dice. However, since most failures with tube amps are the tubes, maybe he's selling the amp because a tube failed and he's too lazy/cheap to replace the tubes himself.

In any case, plan to replace the tubes. Add that to the cost of the amp when you're trying to determine if it's a fair deal.

[-=MYK=-]

Originally posted by martinrr I'm hoping he's a moron.

 

 

I happen to know the guy.

 

You should get it and not call him a moron. He does frequent this board, btw.

[-=MYK=-]

[Lucius]

Originally posted by -=MYK=-

lol, everytime I see your avatar I think you're mad! Cheers Lucius

[-=MYK=-]

Originally posted by Lucius lol, everytime I see your avatar I think you're mad! Cheers Lucius

 

 

Strange.

 

I always think the same thing:o

 

Where did your signature go?

 

I was starting to like it:thu:

[Lucius]

Originally posted by -=MYK=- Strange. I always think the same thing:o Where did your signature go? I was starting to like it:thu:

 

 

It annoyed me faster than it annoyed anyone else. Cheers Lucius