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Kenwood KA-7300 Integrated Amplifier Issues

Not sure what to say, borrow one then. It's important especially on this amp to match as there is no offset adjustment.
 
UPDATE:
Well had gotten the transistors in today, and was able to match them as closely as possible (3 of them I got to match at 528 and one at 527) and anyways went to install them into the amplifier and I got the first two in with no problems but then the last two when I went to install those was where I ran into some problems.

The circuit traces that the solder is supposed to go onto when attaching the transistors decided it would lift away from the circuit board and then break off, and all I did was hold the soldering iron to the solder long enough to pull the old transistors out of the circuit (which was barely 10 seconds) and so now I have no way to attach the transistors to the circuitboard anymore, and this was actually what I was afraid was going to happen.

So it looks like unless someone on here has a good way to fix those circuit traces this unit its pretty much done for.
 
I think he means to solder a piece of wire to one of the transistors legs and just solder the other end of the wire to where the trace would normally connect to. I can't even begin to tell you how many traces I have destroyed but was still able to rig up a connection.

We called it jury rigged or jerry rigged whichever you prefer but it still worked in a pinch.
 
cademan said:
I think he means to solder a piece of wire to one of the transistors legs and just solder the other end of the wire to where the trace would normally connect to. I can't even begin to tell you how many traces I have destroyed but was still able to rig up a connection.

We called it jury rigged or jerry rigged whichever you prefer but it still worked in a pinch.
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I know what he's talking about but like I said its not going to work because the soldering point that the transistor needed to solder to broke clean off the circuitboard leaving nothing but the circuit trace behind and nothing to solder to, and both transistors did that to me when I tried replacing the second set of transistors (like I said the first pair of transistors went in without any issues.)
 
scrape the coating off the trace and tin it .then bend the transistor lead over it and solder in place . 10 seconds is a pretty long time .. 5 seconds is about max .
if the lead wont reach add some wire to it so it does .
 
petehall347 said:
scrape the coating off the trace and tin it .then bend the transistor lead over it and solder in place . 10 seconds is a pretty long time .. 5 seconds is about max .
if the lead wont reach add some wire to it so it does .
Click to expand...

yeah but 10 seconds was how long the solder on there took to heat up and then I had to keep the solder heated up in order for me to be able to get the old transistor pulled out of the holes because otherwise the solder would solidify and then there would be no way for me to get the transistor out of the circuit, also I was trying to use a desoldering bulb to try and clean off the solder off the solder joints but the solder joint was too small for me to be able to get a soldering iron and desoldering bulb in there at the same time, like I said it was the same process I did to remove and install the first set of transistors and I didn't have any issues with those.
 
cademan said:
Try Solder Wick! It works excellent for me! Solder bulbs also work but I like the wick the best.
Click to expand...

I have some solder wick, and for some reason it never worked for me quite like it was supposed to, it actually ruined soldering points whenever I used it.
 
petehall347 said:
scrape the coating off the trace and tin it .then bend the transistor lead over it and solder in place . 10 seconds is a pretty long time .. 5 seconds is about max .
if the lead wont reach add some wire to it so it does .
Click to expand...

10 seonds was actually how long it took for that old solder to heat up and then on top of that I had to keep the solder heated up so that I could pull the old transistor out because otherwise the solder would of solidified back up and I wouldn't of been able to get the transistor pulled out.
 
That's an easy fix! Just scrape with a razor blade or Xacto knife the green protective film directly above the trace and just solder a wire to make the closed circuit. I do this all the time!
 
cademan said:
That's an easy fix! Just scrape with a razor blade or Xacto knife the green protective film directly above the trace and just solder a wire to make the closed circuit. I do this all the time!
Click to expand...

That's the problem I don't have an x-acto blade or a razor blade, plus with my luck with repairs like that I would only make it worse. :sigh:
 
Any sharp object, a hunting knife or even a knife from the kitchen will work. Once it is scraped, you will see the original copper trace and solder will stick to it like a fly on fly paper. :yes:

Just use a spare piece of cut wire to solder the transistors leg to the copper trace!
 
cademan said:
Any sharp object, a hunting knife or even a knife from the kitchen will work. Once it is scraped, you will see the original copper trace and solder will stick to it like a fly on fly paper. :yes:
Click to expand...

I appreciate your vote of confidence but I really don't think I could do it, like I said more than likely I'll just make it worse and possibly even tear up the circuit trace even more, my hands are not very steady and because of that I can't make very exact cuts or what not without running the risk of damaging things more, case in point when I went to try and recap the power supply in my old Grundig Console I have I went to try and strip the wire to one of the power supply caps so I could install the new ones and one of the wire leads kept breaking off on me when I tried stripping it back and it took me 4 tries to finally get some bare wire exposed on the wire lead without it breaking off the wire, and all I used was a regular wire stripper, but I contribute that incident to the fact that the wire was such fine gauged wire that even with the finest gauge stripper available to me on my pair of wire strippers it still broke the wire, that's why I don't trust myself with such fine detailed tasks.
 
Ok then, try sand paper. I don't think you could really hurt it. It is very repairable but if your fingers are not up to it then maybe see if someone else can do it for you. I can!:D Send it to me! :yes: :D
 
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