Oh yes, I keep foreign languages to a minimum.  When Al Gore invented the internet, he also dictated a new world language...

Check this out though.  The local store charged me $15 for one of those puppies, and said they listed at about $25... The two from Thailand were $5.33 shipped!  So if they send me 2 million, I'll be opening my own store!

Thanks again,

Antonio

I got impatient and didn't want to wait 2 weeks for the TDA2030A to make its way here from Thailand, so I dropped by the local music store.  They didn't have one, but they told me who would.  So I go to this parts store, get a new amp and a new input jack.

The clean channel is back, but the overdrive channel is still gone.  Now, the original jack had 4 prongs, the new one 3, even though they both short the jack when unplugged.  So I thought the 4th prong from the original jack drives the overdrive channel.  A little more soldering and this thing should be back as it should be.  Not!  I'm getting a little sound from the overdrive channel now, but still way less than normal.

I now wonder what else had blown out.

Y como no tienes nada mejor que hacer que ayudarme con este rompecabezas, espero tus consejos! 

Bingo, I think.  I got 11.3v on 5, but hardly anything on 0.8v on 3 with a few millivolts on 4.

Seems finding a new amp of these should be easy enough.

I'll close the thread once I get one in!

Thanks again,

Antonio

Make sure to hold the two red wires when plugging it in for max effect.  Got it!   

Will let you know what happens (with the real test that is.  As a kid, I got a taste of 220V while plugging a lamp.  Lesson learned for life, trust me).

Antonio

You know how it is.  The most obvious thing is often the one you miss.  How about that 3rd chip, with the large cooling fin attached to it...  Well, I rather assumed the issues would be in the low end, since even the headphone jack was silent.  Anyway, it's a TDA2030.

At any rate, the pictures of the board can be found at http://www.elnonio.net/web/amp.php  I cropped but didn't resize the pictures so as not to loose any definition, but did put thumbnails.  Firefox works great using large pictures anyway (sorry if you use IE...)

I really appreciate your willingness to help out even though it's costing us both more in terms of time than the actual value of getting a new one!

I fear miscommunication has occurred!  There's only two chips, not four.  What I should have said is that one says "4558D JRC 1168H" and the other says "4558D JRC 1046D". 

There is nothing on the board that shows where the failure point could be (no discoloration, let alone any flash/burn), and none of the components looks abnormal either.

Stumped (haha),

Antonio

The speaker is definitely good.  The two amps are JRC 4558D, one has 1168H and the other says 1046D.  You think those are the likely failure points?

I've been looking for the schematics online, no luck.  Not sure it would really help anyway, but I could/should start testing the components individually, and who knows, maybe I'll get lucky and find the culprit.

Don't read too much in the handle (aNtONIO, what a kid I used to babaysit callled me since she couldn't say Antonio)

Hi

I've just inherited a Johnson 15 (amp says standard, but looks like rep tone).  Power source is good, led lights up.  Speaker is good, but it has stopped producing any sound.  I'm thinking about rebuilding the electronics  while keeping the pots design.  Ideally it would keep the clean/overdrive functionality, with 3 tone eq and the headphone jack.  The pedal jack I'd like to replace with a line in to plug in an ipod or a cd player for beat tracks.  I'm into bluesy rockish music, that type of tones.

Now, I'm not lazy, but I am at the Navy's postgrad school and time is at a premium (as in, I have little time on top of regular duties).  I'm doing a bit of research, but I'm hoping one of you guys will recognize the perfect solution for the problem at hand.

Many thanks in advance,

A. Contreras