How do you clean dried soda pop from an amp's circuitry ?? Valvestate

[Lucid_Delirium]

I purchased a used Marshall avt275 for nostalgic reasons a couple months ago (it's what i learned and played through for years). Been fully enjoying it..

Finally decided to completely remove all funk from inside and out to make it mine for good. It was all going great until i pulled the chassis out and saw that the chip board was covered in something that appears to be dried coca-cola in the area bellow the top vent... Its all dry and glue like.. A complete ghastly mess, but strangely the amp has worked fine with no issues... A testament to old British craftsmanship i suppose.

I panicked and removed most of it with classic WD-40 and a bunch of fine bristle toothbrushes before googling anything... I since read that WD-40 is bad for amp chips...(Can't be worse than dry soda pop though.. I hope) Amp still works fine after i let it dry...

So my question is, how would you guys go about getting this chip in the best condition possible??? I'll post some before and after WD-40 pics for everyone to see the horror show..

Lesson learned.. Always thoroughly check old amps before you buy. I'm hoping that I'll be lucky and my amp will survive this open heart surgery...

Any help is welcome.

 

[twilt1973]

Wow, what a mess in there!
If it were mine, I'd use Isopropyl (rubbing) alcohol and Q-tips to clean it up.

~Troy

 

[LyseFar]

Find someone with an ultrasonic cleaning bath and an electronics drying oven. Pull the board and put it all in. That will do the trick. Remember to drain the caps first…

 

[Lucid_Delirium]

I got some rubbing alcohol to try first. If I'm not satisfied with the results, I'll give the ultrasonic bath method a go. Great advice. I thank you both

 

[PelliX]

I got some rubbing alcohol to try first. If I'm not satisfied with the results, I'll give the ultrasonic bath method a go. Great advice. I thank you both

Note that while the ultrasonic bath is the best method to get all the muck out of there, it can damage some components like pots. You'll probably be OK, but it should be mentioned. Some caps don't take well to the process either, neither do crystals. There's no need to drain the caps here, that should happen within a minute or two after the amp is powered down, but also note that you will need to apply new thermal paste to any heatsinks and such (think output transistors).

 

[Ufoscorpion]

I purchased a used Marshall avt275 for nostalgic reasons a couple months ago (it's what i learned and played through for years). Been fully enjoying it..

Finally decided to completely remove all funk from inside and out to make it mine for good. It was all going great until i pulled the chassis out and saw that the chip board was covered in something that appears to be dried coca-cola in the area bellow the top vent... Its all dry and glue like.. A complete ghastly mess, but strangely the amp has worked fine with no issues... A testament to old British craftsmanship i suppose.

I panicked and removed most of it with classic WD-40 and a bunch of fine bristle toothbrushes before googling anything... I since read that WD-40 is bad for amp chips...(Can't be worse than dry soda pop though.. I hope) Amp still works fine after i let it dry...

So my question is, how would you guys go about getting this chip in the best condition possible??? I'll post some before and after WD-40 pics for everyone to see the horror show..

Lesson learned.. Always thoroughly check old amps before you buy. I'm hoping that I'll be lucky and my amp will survive this open heart surgery...

Any help is welcome.

I allways follow this one piece of good advise I got from someone years ago , don’t try and fix something that ain’t broke

 

[Matthews Guitars]

Water is the solvent for that. Fill a spray bottle with water, spray it, blot it dry, repeat several times until clean. Follow with a hair dryer to fully dry it out before powering it back up again.

Simple approaches work best.

 

[Ufoscorpion]

Same with tea and coffee

 

[paul-e-mann]

I think I would have hit it with electronic spray like Deoxit then scrubbed it up with a toothbrush and wiped it down with a dry cloth and q-tips or something.

 

[speyfly]

I've had luck using a steam iron holding it away from circuit boards and components. The area will get damp, not wet and can be wiped down with q-tips, old tee shirt or other absorbent materials. Multiple applications may be necessary.

 

[PelliX]

A lot of these suggestions are OK to restore it visually, but if you want "in depth" cleansing you'll want a solution that gets in under the caps, between the legs of transistors and so on. Apart from the optical point of view, any contamination (drinks, sweat, water, whatever) can become conductive and start to cause issues. Granted, in this amp there's fair spacing, no SMD circuitry, no IC's and such but the ultrasonic cleaner is the only way to get in there without dismantling most of the components. Also note that one should be a little careful wiping boards with fabrics - you can easily build a charge on a (partly) synthetic t-shirt that will fry a transistor.

 

[Whizzercone]

If it wasn't cleaned immediately, you don't.

 

[DonP]

I allways follow this one piece of good advise I got from someone years ago , don’t try and fix something that ain’t broke

I think the phrase is “if it ain’t broke don’t fix it “.

 

[vivanchenko]

Here. Make sure that power is off, and the filter caps are discharged.

 

[vivanchenko]

Jokes aside, just use alcohol and a few brushes. That's how PCBs are cleaned after soldering. The higher is the concentration of alcohol, the better. I use 95% ethanol (rubbing alcohol). Don't use water and q-tips. You can wet the PCB with alcohol generously and let it dry for an hour or so. This method is 100% safe, (as long as you discharge those filter caps )

 

[Lucid_Delirium]

I spent hours with a bottle of rubbing alcohol and a toothbrush today.. The chip looks nearly new again so I'm gonna throw in the towel on the repairs. It worked fine before too amazingly, but that was just too much funk to live with... I'm very relieved that i didn't break what wasn't broken tbh like someone wisely mentioned.. Jammed for hours. All is good!

Thanks for all the advice my rocking comrades!