Sad happenings my guitar gently died.

[labguitar1003]

so today i came home and plugged my guitar in, turned my amp on and had an extremely loud scream for about 3 seconds and them a pop and no sound, so i think it is safe to say that the electronics are fried and now i will have to take it apart and rewire everything. ( thats what you get for using a cheapo ibanez for parts) so i decided to go all out and give it some long needed upgrades like push pull pots, a better finish, a new neck, and a new bridge pickup. i will be gathering money and parts for a while but hope to keep you guys updated, working on a mock up right now.

 

[reinhold]

Are you sure it's the guitar and not the amp? 

 

[labguitar1003]

i tried the amp with another guitar and it worked and tried the guitar(the one suspected of bad wiring) on another amp and it didnt work. so im pretty sure its the wiring its really atrotious.

 

[mayfly]

It's tough to damage guitar electronics - unless they are active.

If you're running passive parts, I bet that if you clean up the wiring you can get it to work.

 

[line6man]

It's tough to damage guitar electronics - unless they are active.

If you're running passive parts, I bet that if you clean up the wiring you can get it to work.

Yeah, you're basically talking a low Q inductor and a few resistors and a (usually high voltage) cap.
The only way to fry anything would be to run a high enough current through a pickup coil to either act like a fuse, or melt the insulation, causing it to short.

 

[labguitar1003]

It's tough to damage guitar electronics - unless they are active.

If you're running passive parts, I bet that if you clean up the wiring you can get it to work.

Yeah, you're basically talking a low Q inductor and a few resistors and a (usually high voltage) cap.
The only way to fry anything would be to run a high enough current through a pickup coil to either act like a fuse, or melt the insulation, causing it to short.

ya i think i did something when i was installing a new pickup. i might have burnt a wire or it may just be because its so messed up with about 50 wires in there that it might have done something to the electronics.

 

[swarfrat]

Your amp's input stage is also unlikely to fry anything -it's a very high impedance. Does the guitar have active pickups or a preamp?

 

[-CB-]

If the amp fried one, it would fry all.  It can happen if you short grid to plate on the input.  Exceedingly rare, but...  but thats not the case!

Check for a loose ground connection on the output jack, and/or loose ground someplace else.  Look for mechanical damage on switches - mini toggles are especially prone to damage from the toggle getting abuse (like in a case, bouncing).

Its fixable.

 

[line6man]

If the amp fried one, it would fry all.  It can happen if you short grid to plate on the input.

I'm not knowledgeable on amp designs, so I could be wrong, but wouldn't there normally be capacitive coupling before the control grid of the first gain stage that would block DC?

Also, come to think of it, depending on the actual voltage and pickup resistance, the current through the pickup coil may not exceed the ampacity of the wire.

 

[OzziePete]

I reckon if you have a passive pickup system within your guitar it's a component failure or some wiring stuff up and that it is quite fixable. Active system : might mean a preamp is gone... Never heard of a guitar 'dying' unless they were burnt or smashed beyond repair.

 

[line6man]

Also, come to think of it, depending on the actual voltage and pickup resistance, the current through the pickup coil may not exceed the ampacity of the wire.

Nevermind. I missed a decimal point doing this in my head. :doh:

If you had a 300V plate voltage, with a 10K Ohm pickup, that's 30mA, which sounds like a lot.
And if perhaps two pickups were in parallel at the time this happened, that would more-or-less double the current.

It's plausible that a pickup's wire could melt if the anode of the first gain stage's tube were to short to the control grid, but, that's assuming there was direct coupling, and if only one pickup was selected, only that pickup would fry. In any case, if such a short were to occur, the amp and other guitars would not continue to function normally.

My money's on the possibility that a wire either came loose or shorted to ground on the guitar in question.

 

[swarfrat]

The plate and the input stage grid are not normally connected. There are some tone shaping circuits that do it, but you can accomplish the same thing bypassing to cathode and its a lot safer. I couldn't find a wire gauge chart with current capacity for 42ga before I lost interest, but I don't think 10mA would fry it. It might fry you though.

 

[elfro89]

Also, come to think of it, depending on the actual voltage and pickup resistance, the current through the pickup coil may not exceed the ampacity of the wire.

Nevermind. I missed a decimal point doing this in my head. :doh:

If you had a 300V plate voltage, with a 10K Ohm pickup, that's 30mA, which sounds like a lot.
And if perhaps two pickups were in parallel at the time this happened, that would more-or-less double the current.

It's plausible that a pickup's wire could melt if the anode of the first gain stage's tube were to short to the control grid, but, that's assuming there was direct coupling, and if only one pickup was selected, only that pickup would fry. In any case, if such a short were to occur, the amp and other guitars would not continue to function normally.

My money's on the possibility that a wire either came loose or shorted to ground on the guitar in question.

I swear joey is a rocket scientist. Or a porn star with an electronics hobby

 

[mayfly]

If the amp fried one, it would fry all.  It can happen if you short grid to plate on the input.

I'm not knowledgeable on amp designs, so I could be wrong, but wouldn't there normally be capacitive coupling before the control grid of the first gain stage that would block DC?

Nope.  The majority of tube amps only have an RF blocking resistor between the guitar and the grid of the first input stage tube.  So... it is possible (although unlikely) that the grid could short to the cathode or something.  But trust me - if it did you would KNOW!

 

[NLD09]

If the amp fried one, it would fry all.  It can happen if you short grid to plate on the input.

I'm not knowledgeable on amp designs, so I could be wrong, but wouldn't there normally be capacitive coupling before the control grid of the first gain stage that would block DC?

Nope.  The majority of tube amps only have an RF blocking resistor between the guitar and the grid of the first input stage tube.  So... it is possible (although unlikely) that the grid could short to the cathode or something.  But trust me - if it did you would KNOW!

Well you might know. I'd just be like, "Wtf... my amp died!"

well you might know.

 

[mayfly]

If the amp fried one, it would fry all.  It can happen if you short grid to plate on the input.

I'm not knowledgeable on amp designs, so I could be wrong, but wouldn't there normally be capacitive coupling before the control grid of the first gain stage that would block DC?

Nope.  The majority of tube amps only have an RF blocking resistor between the guitar and the grid of the first input stage tube.  So... it is possible (although unlikely) that the grid could short to the cathode or something.  But trust me - if it did you would KNOW!

Well you might know. I'd just be like, "Wtf... my amp died!"

well you might know.

If the grid shorted to something in there, you'd get a massive jolt.  More like "WTF - I died!"

 

[line6man]

If the amp fried one, it would fry all.  It can happen if you short grid to plate on the input.

I'm not knowledgeable on amp designs, so I could be wrong, but wouldn't there normally be capacitive coupling before the control grid of the first gain stage that would block DC?

Nope.  The majority of tube amps only have an RF blocking resistor between the guitar and the grid of the first input stage tube.  So... it is possible (although unlikely) that the grid could short to the cathode or something.  But trust me - if it did you would KNOW!

This is terrible news for all those people that insist upon 600V tone caps for "safety reasons". :laughing7:

I agree though, if there is a short, you are going to know very fast, AND, the amp will not continue to work with other guitars.

 

[Jusatele]

It's tough to damage guitar electronics - unless they are active.

If you're running passive parts, I bet that if you clean up the wiring you can get it to work.

Yeah, you're basically talking a low Q inductor and a few resistors and a (usually high voltage) cap.
The only way to fry anything would be to run a high enough current through a pickup coil to either act like a fuse, or melt the insulation, causing it to short.

ya i think i did something when i was installing a new pickup. i might have burnt a wire or it may just be because its so messed up with about 50 wires in there that it might have done something to the electronics.

50 wires in the guitar? ok we need to rethink this

 

[labguitar1003]

[/quote]50 wires in the guitar? ok we need to rethink this
[/quote]

ok maybe i over exaggerated but it really is a big mess.

 

[Jusatele]

yes, I think we do need a few clarifications

first, what was the amp brand and model (seems a lot of amp talk going on without having asked this)
second, a schematic of the guitar wiring and the value of the parts used
third, maybe a few pics of the makeup and layout of the guitar parts

without these, we can discuss things all day long, but are just spinning a lot of hot air as we do not even know if we are talking tech related to your incident.