Fender Pro 185

[GarySeelen]

Hi Everyone,

I have  1988 Fender Pro 185 that is giving me a hell of a time. I know there is another post on here about it, however I can't seem to find it.

My issue is that when I start it up it works fine and then all of a sudden my sound gets weird... it's  not really distortion.... but its like a robotic farting noise... and it only occurs when I strum my guitar. when theres no input the amp doesnt hum.... its only when I strum that Mario cuts the cheese.

doesn't matter which channel....

when I tap on the top of the amp with all the gentleness of an angry german nanny named olga the farty noise goes away... breifly.

Is this characteristic of the filter Caps going?

I've tried resoldering the vast majority of the solder joints underneath, but still to no avail.

Also the portion that seems to reduce the fart noise when tapped is the part labelled "C78" which i believe is the filter cap. 

Help me SS gurus .... you're my only hope!

[DrGonz78]

My advice is download the schematic from this link below... Look for post from Stratorius for the Schematic info then go right below his post and READ ENZO's post. Now we can assume you completely removed all the solder from the joints of the main Filter caps... I hope. Just reflowing the solder may not be enough... If not do this now as it points to loose solder joints on the caps. Change the caps too as they are nearly 25 years old.>>> But this might be the link you were looking for too.??>>>

http://www.ssguitar.com/index.php?topic=1673.0

[J M Fahey]

Agree and add; since Aluminum can't be soldered, connections inside the Electrolytics are riveted, meaning they rely on mechanical pressure.
Years of vibration, specially on heavy parts such as those, tend to crack them internally.
So sometimes resoldering is not enough and you must replace the part in full, as suggested above.
Good luck.

[Enzo]

I don't remember what I may have posted elsewhere, but I doubt the caps are failing, but I'll bet my lunch money the main filter caps need to be resoldered.