diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Solid State (http://www.diyaudio.com/forums/solid-state/)
-   -   Aragon 8008BB needs repair (http://www.diyaudio.com/forums/solid-state/185301-aragon-8008bb-needs-repair.html)

Scott Stansbury 17th March 2011 10:14 PM

Aragon 8008BB needs repair
 
2 Attachment(s)
So, hypothetically only, of course, assume that your cat gets sick and throws up on your Aragon 8008BB. Suppose that led to an immediate, discrete little snap from one of your speakers ( let's say that they are Thiel 3.6's). Your CD had just finished so there was nothing playing at the time, but hitting play again shows one channel gone. Continue supposing that you open up the amp to check things out and find a "bit" of said fluid shorting out the 3 leads of Q15. Where would you start to find what is blown? I have a DVM, signal generator, 100MHz scope, etc., but very new to the troubleshooting game. Any tips (step by step won't offend ;) ) would be very appreciated.

I've attached the appropriate schematics...


Thanks in advance!
Scott

dave_gerecke 18th March 2011 03:09 AM

First suggestion, shoot the cat.:D

Ok, that's probably a little rough. Can't say that I can give you any other suggestions.

Peace,

Dave

P.S. I do like cats, but something like that would bring me very near my limits.

Scott Stansbury 18th March 2011 03:14 AM

Well, to be honest, that was my first thought also... ;)

geraldfryjr 18th March 2011 03:32 AM

I had that happen to an orginal sylvania superset once.

I did manage to get it running again after replace some traces and wires.

But, boy did it smell for the rest of its ownership.

An ARAGON no less, my heart goes out too you!

The very first you should do (depending on how bad it is) is take some dawn or some thing similar and wash, rinse and repeat and then let dry throughly (say few days to a week) and then you may proceed. jer

p.s. and use a small (toothbrush) brush aswell.

Sebastiaan 18th March 2011 04:32 AM

1 Attachment(s)
After you follow the above instructions, you should actually test the C-B-E conductions of all transistors. Unfortunately that means in most cases you have to solder them out.

Good luck!

With kind regards,
Bas

geraldfryjr 18th March 2011 04:43 AM

Thats how we used to do it in the ol'days luckily it doesn't have as many parts as tv chassis.

Start with the outputs and work your way back.
But check around the op amp first as well.
Any gunk on this device could cuase it to swing to one of the rails. jer

Scott Stansbury 18th March 2011 01:43 PM

Thanks guys, that's exactly what I'm looking for.

Given that I've got a a scope and a signal generator, does it make sense to apply a signal to the bad channel and trace back in the circuit until I see some semblance of the signal and start checking transistors from there? Or, because of the feedback, is that not going to show me anything interesting?

Continuing thanks!

Scott...

geraldfryjr 18th March 2011 03:16 PM

Yes as long as the fuse are good and nothing is burning up or sizzling.
But clean it first you might just luck out and there might be any thing wrong with it.
Becarefull not to adjust or move r43 this is the bias control just in case it does work. jer

geraldfryjr 18th March 2011 03:21 PM

When your talking about puke it is acidic and does conduct when it is moist and wet which is probably why you heard the sizzling sound.
In my t.v. set all it did was burn a few wires up.
And I think I had to put a new IFT in it.
I don't remember as it was in 1984. jer

geraldfryjr 18th March 2011 04:01 PM

1 Attachment(s)
I'll give an example,
I got tired of the master slider on my mixer cutting out so rather than taking the whole thing apart again I decided to pour some isopropynal alcohol in it to clean the slider.

Well this worked, but as the solvent started to flow around all the other components and opamps all kinds of nasty pops ,clicks and noises started to come out of it and rendered the master section useless.

Since I run my amps wide open it became very annoying and had become a drangerous situation to my speakers and I had to shut every thing down.

It worried me that the the silder may need to be replaced as somtimes this can happen, only I wasn't up to it .

The next day after it dried out, all was well and there was no noise and it is now dead silent like it is supposed to be.

However I do needed to replace the slider as it still works and doesn't cut out in the middle of it's travel any more.

I do not suggest at all in doing what I did, as it was late at night and I was being lazy.
It is quite a job to get it apart and is fairly heavy. jer


All times are GMT. The time now is 04:38 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio


Content Relevant URLs by vBSEO 3.3.2