OK. JM Fahey, Wrong terminology.. . . .The diode 'shorted' (blew) for want of a better term so that it acted like a resistor as opposed to a diode. Sorry for the faux pas.

SUCCESS! So, I installed the new filter caps and one of them blew immediately. I took a wild guess and I began testing the diodes in the rectifier circuit and BAM! One of them was shorted open. I thought this only happened with a massive overvolt condition, but apparently it was weak (or something).

SO, the amp is MUCH quieter. I think I need to repair the shielding in the cabinet and make sure the ground from the amp to the cab is good and I believe I have repaired this thing.

Thank you to everyone who weighed in. I've never experienced a diode shorted open before!

    Sorry for going dark for a bit. Also sorry about the post about the XFormer leads. What I was trying to say (poorly) is that you can't read the writing on the board. After looking more closely, for some reason, mine's marked on THE BACK! So, that's sorted....
    Ok, I have the Xformer hooked up correctly (just wanted to cross that off of the list). I appreciate all of the help. I went through some other steps (isolating the -pre, checking grounds, AFTER re-soldering all of the joints, etc (and testing after each step to isolate variables).
   I then hooked the amp up without the reverb tank attached. No change
   The hum is present with nothing plugged in. It is constant in volume and can somewhat be overcome with signal (basically turning up the amp). It is also exactly the same regardless of what cord, guitar, etc., is plugged into the amp. I've measured the outputs of the transformer and they are well within normal range.
I plugged into the 'Pwr In" circuit to see if there was any change and there was none.
I replaced the caps about 2 years ago and it did thing to change the hum. I still, with all of the information I have,,am leaning towards the caps  being bad.. I checked my receipts and cannot find the one for two 2200uuf, 50V caps. These have no markings on them and I'm beginning to wonder if I have some shady crap I bought when I was broke. I'll have the new Nichicon caps (direct replacements) in hand tomorrow. I truly appreciate everyone's help and will post an update when I get them in.

Thanks. The board in the one I have has 10 different spade terminals in the area where the power supply hooks up and none of them are marked with a color / voltage. You post helps. THANK YOU!

Hey, I think I may have found he problem: The transformer outputs look like they have been hooked up wrong. I've checked the schematic I have and I can't tell from it (it's a crappy copy and I can't find another one) if the Xformer leads are attached to the board correctly. Does anyone have a picture of the fully connected board / power supply?

There are several 'options' to attach it and I just don't want to bung something up. Thanks in advance!!!

THANK YOU! I don't know why I didn't think of that. I'll be on it this afternoon.  :duh

Ok,
    I may have posted about this before, but I cannot find it. I have an old Princeton 65 SS amp. It is so noisy it's unusable. I've resoldered and then replaced the power caps and no change. I've resoldered all of the connections on the PCB and it made no difference ('refreshed' the solder). I've tried several guitars, cables, etc, and can not change the noise that way. It's 60-cycle hum. I have conditioned power to plug it into, a shielded studio (HAM radio operators made that a necessity. I basically have a Farraday cage in my basement HAHAHAHAHA!), have tried it in several circuits, in several locations (inside and outside of my house), and no change.

   I've also swapped out the input jacks and have not had any luck. Fender SS amps are 'noisy' out of the box but this is insane. ANY help would be appreciated. I was an electronics tech in the Army and work in the industry now, so I'm not a novice, but I simply cannot figure this thing out! I love the amp (when it works) but am about ready to set it on fire! Thanks in advance!

I have a reverb tank and a phono preamp. I am going to make a satellite reverb unit to use with my Laney AOR 100 Pro Tube (yes, a tube amp. I know it's a "nono" here haha). Do I have to use a balance potentiometer to make a "wet / dry" adjustment or can I use both sides of a standard pot? Thanks!!!! Erich

HA! It's a TDA2030 and I have an old Epiphone 10W amp with a blown transformer. I'm going to try to change the amp IC to see if that is what was wrong!!!! I figure, hey, it's free, right? I'm still open to suggestions and I'll update this when I'm done!!!! "I'M GOIN' IN"

Howdy, All! Love the forum.
I got a Kustom KLA-10 amp from a friend and I want to fix it for my nephew. I had to replace the input & headphone jacks because the plastic I.C. mounted ones were both broken. I have power, the transformer works fine and I have low volume through the headphones and none through the speaker. I think it's the IC mounted on the heat sink ("power" portion of the amp). I'd like to know how to check it with my voltmeter to verify that's the problem. I am actually pretty hndy with this kind of thing, just not much experience with small SS audio circuits. I recondition tube amps and build guitars for a hobby!!
Any help you folks can offer would be appreciated. Oh, yeah, the IC has what looks like TBA2030A on one line and 8BA41B on the second. Thanks, again! Erich