Crate G130CXL crankling and popping

[FreaKouT]

Hi all, i'm new in this forum, and i was given a Crate G130CXL.
The amp has some noise standing alone without anything plugged in. So it's not a guitar problem...
When i play, my bass guitar (it's a guitar amp, I know), the lower cords, it cranks even more.
I opened it up and sprayed the both circuit boards with some contact cleaner, and the crankling remained.
Any ideas of where i should start to search for the problem?
Thanks

[Enzo]

Isolate the problem.

DO ANY of the controls have ANY effect on the noise? In other words do any volume controls make it louder or softer? DO the tone controls change the tone of the noise? Does it matter which channel is selected? Does turning the reverb down make a difference?

Turn the reverb down, ball up your fist, and whack the top of the amp. Does the amp respond to the whacking with noise? Does whacking it stop the noise? That looks for loose connections inside.

I forget, but I expect the amp has either FX loop jacks or power amp in jacks. Plug a guitar into the power amp in jack and turn the guitar voilume to zero. Still noise or not? No power amp jack? Then the FX return jack. same question.

[soundguruman]

You are not supposed to spray contact cleaner on circuit boards, unless it's just the contacts.
Resolder all the connections and clean the controls. Use real control cleaner (such as caig deoxit D100)to clean controls. Do not use contact cleaner on moving parts or plastic.

[FreaKouT]

so for the isolation:
None of the controls has effect on the noise, except the volume.
The tone controls, don't affect the noise.
Both channel A and B make the noise.
The reverb doesn't make a difference.
When i tap the amp it seems to turn off and on again, at least the leds turn on and of again, and there is more noise when doing that.
All this with no guitar plugged in.
Thanks

[FreaKouT]

I used it everywhere in the circuit boards, volume and jack plugins.

[soundguruman]

I think all that it needs is for the circuit board to be resoldered. We usually do the whole board, and it does not take so long to do it.
You may find that resoldering takes less time than trying to narrow it down to one area or one connection.

[FreaKouT]

i might do that, don't know about my iron capability, but i may try...
thanks

[soundguruman]

It actually takes experience and a temperature controlled soldering iron. Use a magnifier to make sure that you have not accidentally bridged the circuit tracks. OR get an experienced person to help you.

[FreaKouT]

I just resoldered the highlighted area, and it got somewhat better.
If i play the bass real strong, it no longer cracks ou pops.
When i tap the top of the amp, it no longer cracks or turns off and on.
But it still have some residual noises sometimes...
And another thing, this thing i highlighted (wich i don't know what it is) kind of gets hot, is it normal?
Thanks

[soundguruman]

resolder the whole board.

[FreaKouT]

And about that two white pieces, is it normal for them to get hot?
The others similar pieces along the circuit board, don't heat as much...

[52 Bill]

Yes, they are power resistors and they can get hot. They are for reducing the voltage from the power amp down to a level that is usable by the preamp ic's.

The other large resistors are emitter resistors for the output transistors. They will not get hot while the amp is at idle.

[Larry New]

Crate g130cxl

Hi all, i'm new in this forum, and i was given a Crate G130CXL.
The amp has some noise standing alone without anything plugged in. So it's not a guitar problem...
When i play, my bass guitar (it's a guitar amp, I know), the lower cords, it cranks even more.
I opened it up and sprayed the both circuit boards with some contact cleaner, and the crankling remained.
Any ideas of where i should start to search for the problem?
Thanks

First off using a bass guitar on a regular amp is a total no-no.You just made problems worse. Second .It's a board problem.probably a capacitor that has been overheated and needs professionally repaired.Third.Never buy used equipment unless you get a warranty.

[J M Fahey]

First off using a bass guitar on a regular amp is a total no-no.You just made problems worse. Second .It's a board problem.probably a capacitor that has been overheated and needs professionally repaired.Third.Never buy used equipment unless you get a warranty.

How do you know itīs a board problem?
How do you know a capacitor is overheated?
Warranties on used equipment are as rare as henīs teeth.
And even if somebody signs one , there remains the problem of actually honoring it, for lack of parts, schematics, whatever.
When you buy used equipment for half price new or less, itīs implicit that thereīs some risk involved.

[g1]

And to top it off, it's a thread that's been dead for 2 & 1/2 years.
Not a real good start for a first post. Nothing wrong with using a bass in a guitar amp either, unless you push the speaker too hard. The amp doesn't care otherwise.