Sansui 210 loss of FM/AM, then all output

[Logchop]

Hi all,

Was hoping I'd never have to post here about my own equipment giving me issues, but I guess it was inevitable that the day would eventually come.

I have a little Sansui 210 that I've had for a while and has worked perfectly on all functions since I got it. Yesterday, I turned the little guy on to listen to some FM radio and the sound came through clear momentarily, and then it slowly grew quieter as the FM signal meter slowly dropped to 0. Since this happened I get no FM signal through the 210, but there is that typical background FM noise that comes through when not tuned to a station (albeit the noise is irregularly faint). I have tested the antenna and FM reception on my other receivers and I have had no problem, which leads me to believe it's not an antenna/receiving FM signal issue. I don't typically listen to AM, but I'm also getting no reception at all on AM either. The aux worked perfectly yesterday after losing FM, but now upon trying it again today the sound is extremely faint. Additionally, if I move the speaker wires even while the receiver is off (but plugged in to power), feedback will come through the speakers.

I opened the unit to take a look for any obvious flaws (blown fuses, bad caps, loose solder joints) but didn't see anything that caught my eye. I plan on doing a quick deoxit treatment to all the pots (especially the selector pot), but if this doesn't yield any results does anyone have any suggestions on next steps? I'd rather not take it to my guy unless absolutely necessary because everything I've read says the 210 should be easy for anyone to work on, and 210s can be found cheap enough that it may cost more to repair it than to find a new one.

Here's the link to the 210's manual in the AK database: http://akdatabase.org/AKview/albums/userpics/10004/Sansui 210 Owner, Service.pdf

Any help is much appreciated, the 210 may be low powered at only 10wpc but the sound it puts out (when working) is phenomenal. Thanks

 

[Ray Gianelli]

Hi all,

Was hoping I'd never have to post here about my own equipment giving me issues, but I guess it was inevitable that the day would eventually come.

I have a little Sansui 210 that I've had for a while and has worked perfectly on all functions since I got it. Yesterday, I turned the little guy on to listen to some FM radio and the sound came through clear momentarily, and then it slowly grew quieter as the FM signal meter slowly dropped to 0. Since this happened I get no FM signal through the 210, but there is that typical background FM noise that comes through when not tuned to a station (albeit the noise is irregularly faint). I have tested the antenna and FM reception on my other receivers and I have had no problem, which leads me to believe it's not an antenna/receiving FM signal issue. I don't typically listen to AM, but I'm also getting no reception at all on AM either. The aux worked perfectly yesterday after losing FM, but now upon trying it again today the sound is extremely faint. Additionally, if I move the speaker wires even while the receiver is off (but plugged in to power), feedback will come through the speakers.

I opened the unit to take a look for any obvious flaws (blown fuses, bad caps, loose solder joints) but didn't see anything that caught my eye. I plan on doing a quick deoxit treatment to all the pots (especially the selector pot), but if this doesn't yield any results does anyone have any suggestions on next steps? I'd rather not take it to my guy unless absolutely necessary because everything I've read says the 210 should be easy for anyone to work on, and 210s can be found cheap enough that it may cost more to repair it than to find a new one.

Here's the link to the 210's manual in the AK database: http://akdatabase.org/AKview/albums/userpics/10004/Sansui 210 Owner, Service.pdf

Any help is much appreciated, the 210 may be low powered at only 10wpc but the sound it puts out (when working) is phenomenal. Thanks

Best place to start is the power supplies. You can check for basic DC at fuseholders F002/F003, should be 42 VDC. If that's good, move on to the regulated output at the emitter of TR001, which should be 24VDC.

 

[kevzep]

Power supplies is a good place to start.
I've done some work on a few 210's in my time, one had a weak transistor in the IF stage in the FM tuner and a few other "old age" issues..
They are pretty simple to work on, shouldn't take long to track down the issue...

 

[AlTinkster92]

Those smaller Sansui's do punch way higher that there weight class , I had a 210 in Nam and wife now has a 220, both great little receivers Hope you get yours running soon.

 

[Logchop]

Wanted to give an update on this thread... couldn't figure out the problem myself, so took the little 210 to my tech. Turns out there was a bad filter cap and a bad IF transistor on the FM board just like @kevzep said. Thanks everyone for the advice, she's back to sounding great!