carlsbro twin amp 90 guitar - help i am an idiot

[lanesi]

Thought i would make use of boxing day to to clean dirty pots on my amp. Sprayed liberally, including circuit board with my can of contact cleaner only to discover someoone had put a can of mounting glue spray in its place. tried tc clean as best as possible but now no sound when guitar plugged into front high or low gain. Speaker does work when guitar plugged into back effects return and also output jack?

Any ideas. I also sprayed glue into all jack inputs. happy to take any abuse in return for advice.

i have had this amp since the 80s it has a great build and good speaker and sentimental value.

[drewl]

Wow, most likely the glue didn't hurt any components.
Alot of PC boards are coated with material to prevent corrosion for outdoor or military use.

You might get lucky and the jacks have glue on them preventing a connection to the cord.
Try cleaning the jacks with a file or sandpaper.

Do the pots turn?
Try cleaning them with a proper contact cleaner.

[lanesi]

Wow, most likely the glue didn't hurt any components.
Alot of PC boards are coated with material to prevent corrosion for outdoor or military use.

You might get lucky and the jacks have glue on them preventing a connection to the cord.
Try cleaning the jacks with a file or sandpaper.

Do the pots turn?
Try cleaning them with a proper contact cleaner.

Thanks, yes the pots turn freely, the glue is more on the back of the pot. have cleaned jacks, No sound using either high or lo gain input, but can get sound via rear fx return. Obviously no volume or eq controls though. any ideas on how to isolate the problem, power lights are on at the front.sounds ridiculous but am really upset about losing this amp, it's like an old friend. The irony is I was just about to buy a sans amp to try out with it and upgrade all my fx rig. Now looks like I will be spending that cash on a new amp. Gutted.

[mozz]

Try alcohol to desolve the glue.

[TarheelTechinTraining]

Now don't waste the good vodka! Lol . plain old isopropyl alcohol. Sounds like a switching jack might be stuck. Good luck, really. Greg

[xtian]

Wow!! God help you if you go to brush your teeth and grab the tube of sulfuric acid by mistake!

Here's come good Ethanol cleaner: https://www.tubesandmore.com/products/S-CDCC-V510

[olddawg]

Try cleaning the jacks with a file or sandpaper.

Do NOT clean jacks with a file or sandpaper! Have you tried plugging the pre-out or effects out into another amp for test? Anything with a line level input will work, even the AUX or tape in on a stereo. Also simply try plugging a cable from the effects in to the effects out and/or the pre-in and pre-out. If you don't have Caig Deoxit, use the alcohol and a Qtip on the jacks and plug/unplug/spin a plug in the jacks repeatedly. If it has plastic, sealed switching jacks and you got wax on the contacts it could take a little patience. Btw... Next time just blow it out with compressed air or vacuum it with a reducer attachment. On the bright side... At least you didn't spray the whole thing with WD-40! We have all seen that.

[drewl]

I take it you've never had rusted corroded ancient jacks?
You can easily clean the contacts with some light guage sandpaper or file away corrosion from inside the amp, especially if they have glue on the jacks.
I have a small round file that can resurface the tip and ring connections from the front.
Just lightly make contact, not filing away mass.
It may be easier to replace them but I get the feeling the OP isn't a tech with spare parts.

[DrGonz78]

I agree that cleaning the jacks with sand paper or file is not ideal. However, it sometimes can work out okay, but still there is the risk of stripping off metal plating. Drewl has a good point though about CAREFULLY cleaning jacks with file of sandpaper. I think we have all been there and done that, for better or worse. Nothing worse that a circuit board completely drenched in WD40 though. Yuck!!

[J M Fahey]

Glue sprayed pots , jacks and switches were murdered, replace them all, period.
PCB mounted parts and wiring will be fine.

Sanding/filing/grinding rusted/corroded contact parts means they are also junk and need replacement.

Most important is having a perfect contact surface, that's why they come with a Factory applied coating, be it Nickel, Silver, Tin, Chrome, Cadmium or Gold , and the reason is that the base metal, either Brass (good) or Iron (cheapest of the cheap) can and will rust/corrode.

Even Silver and Tin will eventually.

[lanesi]

Thanks. A ca ble between fx send and return results in amp kind of working, Intermittent, loud then quiet, volume. Eq working. Still nothing when using front inputs.

[olddawg]

I take it you've never had rusted corroded ancient jacks?
You can easily clean the contacts with some light guage sandpaper or file away corrosion from inside the amp, especially if they have glue on the jacks.
I have a small round file that can resurface the tip and ring connections from the front.
Just lightly make contact, not filing away mass.
It may be easier to replace them but I get the feeling the OP isn't a tech with spare parts.

No need to condescend. Of course I have dealt with all manner corroded jacks, pots, and switches with 40 years experience. I've even had to assemble replacements from a pile of pieces from old period specific parts in authentic restorations...... Many times repairing the damage done by sandpaper, filing, etc. In my experience sandpaper or filing any contact is a temporary fix, many are plated. It also runs the risk of conductive residue getting in places that it shouldn't. It may start a cascade of other problems. I learned a long time ago there was a difference between "fixing" something and making it work. If the unit worked before the wax was made soluable, I doubt that filing anything is necessary, just simple removal of the wax. Given that is the problem of course.

[olddawg]

Thanks. A ca ble between fx send and return results in amp kind of working, Intermittent, loud then quiet, volume. Eq working. Still nothing when using front inputs.

Read the sticky at the top of the page about the "Dreaded Switching Jacks". You can try flushing them out with some non- residue arisol cleaner. (What we used to call tuner cleaner or TF solvent) Or.. If you have a small syringe use alcohol. (As low water content as you can find) Be careful of flame. Then let it dry and spray a little contact restorer like Caig DeOxit in it while pushing a plug in and out of the jack. It's difficult to know exactly what you have going on without seeing it. But my bet is gummed up switching jacks. Ideally, you replace them.

[Leo_Gnardo]

Nothing worse that a circuit board completely drenched in WD40 though. Yuck!!

Oh yes there is: a circus board drenched in phô, with plenty of nguoc mam, fermented fish sauce. 2nd worst: drenched with pee. But WD40 is bad too, just doesn't have that "ick" factor.

Though it may not sit well with some I've revived jacks with Caig D5 and super light sandpaper, 600, 800, 1200 grit. Best to replace in any case that won't respond to solvents & a little elbow grease.