Sansui 3000A Receiver..No output?

jleon92f

jleon92f

Addicted Member
Hi Group,

I have a few Sansui units, I like my 5000A the best so far. I also have a 3000A that has no output to speakers but, if you plug in the headphones you can hear music fine?:music:

I noticed there were (4) fuses missing in the bottom.:scratch2:

Any ideas thank you,

John.:music:
 
Register to hide this ad
jleon92f said:
I also have a 3000A that has no output to speakers but, if you plug in the headphones you can hear music fine?:music:

I noticed there were (4) fuses missing in the bottom.:scratch2:

Any ideas thank you,

John.:music:
Click to expand...
Without the fuses you have no voltage for output transistors = no output.
The headphone doesn't need much power so I guess they can be driven by prepower transistors. Check output transistors for short circuit
 
Stene said:
Without the fuses you have no voltage for output transistors = no output.
The headphone doesn't need much power so I guess they can be driven by prepower transistors. Check output transistors for short circuit
Click to expand...

Thank you, I had put the fuses in and one out of the 4 blew out as I brought up the variac voltage. The left channel sounds fine through the speaker.

Thanks for the help, I am still learning the art of vintage audio repair.

There are (4) transistors on the back of this amp.

See Picture.
Thanks again,
John.:music:
 
Last edited:
Stene said:
Two of them replaced. Stock type is Bendix B170007 or B170008
Click to expand...

Hi, The newer looking ones on right in the picture are the Left channel?

And the bad older looking ones are the right channel?

Thanks for your assistance on this.
John.:music:
 
Last edited:
Stene said:
Used to be this way
Click to expand...

I found the bad transistor, Fuse did not blow when the screw was removed on this one.

Thanks,
Where can I get new ones?

UPDATE: I bought 10 from Hong Kong, the same Toshiba one on the left channel.

Thank you for ALL your help here.:banana:

John.:music:
 
Last edited:
jleon92f said:
I found the bad transistor, Fuse did not blow when the screw was removed on this one.

Thanks,
Where can I get new ones?

UPDATE: I bought 10 from Hong Kong, the same Toshibe one on the left channel.

Thank you for ALL your help here.:banana:

John.:music:
Click to expand...
From Hong Kong, :scratch2: Are you sure it's not counterfeit. :thumbsdn:
I would choose OnSemi MJ15001 or similar :thmbsp:
 
Stene said:
From Hong Kong, :scratch2: Are you sure it's not counterfeit. :thumbsdn:
I would choose OnSemi MJ15001 or similar :thmbsp:
Click to expand...

Who sells them? I could not get a search on the other #'s.

The ones that are in there now on the Left channel are the Toshiba's.

Thanks,

It's 103 here today in sunny AZ

John.:music:
 
Google

jleon92f said:
It is the Toshiba 2SC1079. You do not have to buy 300 pcs.

I will try it out when they arrive an post the results.

Thanks as always.
John.:music:
Click to expand...

Google counterfeit transistor, read it before you spend any $ in Hong Kong.
Casey
 
nosirrah said:
Google counterfeit transistor, read it before you spend any $ in Hong Kong.
Casey
Click to expand...

Thanks guys for the information. I checked the company that I bought the transistors from and another customer who bought the same transistors. He had no problem with the Toshiba's. But there was another person who got bad ones, a different type though. Who new?

Thanks again for that information.

UPDATE: I installed the new Transistors and now the other channel fuses are blowing and the original channel is ok. Is there a special way to install the transistors? Am I doing something Wrong?

John.:music:
 
Hi there all, I am working on a sansui 3000 A and have very little output volume on the left and normal on the right output volume, until i hit the mono button and then both volume up. could you give me some direction on this . thanks
 
If that doesn't help, you may want to look into the preamp stages. The 3000A I'm working on in my spare time had two transistors hurt in the R channel of the preamp, and exhibited the same symptom. Volume equalizes in the "MONO" mode and all but disappeared in "STEREO" mode. I replaced TR405 and TR407 and a few caps in that circuit and solved that problem. You may want to look near that area as a starting point.
 
You must log in or register to reply here.
Back
Top Bottom