Realistic STA-36

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I have a realistic STA-36 stereo receiver. I am trying to locate a service guide, or just a schematic. I am trying to repair the unit I have. Any help is appreciated.  

Erik

Re: Realistic STA-36
I couldn't find a free one, maybe there's a SAMS on it.

What kind of trouble does it have ? Maybe it can be done without a schematic. Many older analog receivers are similar in design, and you can usually get the pinouts on the ICs, specs on the transistors and all that.  

Re: Realistic STA-36
Sorry for the delay, I have a garbled sounding right audio channel, and the AM won't tune (not a huge deal)

Re: Realistic STA-36
I should add I know it is not the speakers I swapped the left to right and the problem followed, it is on FM, and Aux, I presume phono (dont have a player to test with) and the AM is all static, but the right channel has a low sound compared to the left.  

Re: Realistic STA-36
What kind of equipment do you have ? Got a DVM ?  

Re: Realistic STA-36
I have a dvm, an analog meter, soldering iron etc..  I also have a app on m
y phone that can act as a signal generator, but I dont have a scope. I pret
ty much use it to run my ipod, or other music device through the aux, and i
t had been working great and sounded good until recently.  

I appreciate your help by the way.  Thank you.  

Re: Realistic STA-36
Nine times out of ten "garbled" sound in one channel when the amp doesn't f
ry or go into protection is because of an open driver transistor.  Well may
be 8 out of 10 times.  

Without a scope, the only way to test this is either static ally, which mea
ns the ohmmeter and the device not powered, or to measure the voltages in t
he amps while it is running, on a driver the voltage should only be a half  
volt or so, measuring from base to emitter. It may have forward bias (suppo
sedly) on the base but the emitter is not there, it is more negative or pos
itive than it should be. Except for certain circuits, like class C RF amps  
n shit, the emitter and base should always be within about a volt. Maybe 2,
 but no more. The exceptions are high speed switching transistors and that  
ain't what you got.  

You can still get 2SC3117 and 2SC1249 at Digikey cheap and they will handle
 almost any amp up to about 400 WPC.  

Sometimes it is the outputs, read the voltages on the bases and emitters of
 all of them in the output stages. Even with no signal, on3 of them is goin
g to have more than normal voltage from B to E. Compare it with the other c
hannel.  

Anyway, try a few things and get back to us.

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