Sansui CA2000 no output

[lpm123]

Hi all,

I've just inherited a pair of sansui CA-2000 and BA-2000 pre amp and amp. After plugging them in for the first time, and connecting some speakers, they powered on without a worry but the left channel was a bit weak, then started cutting out. It would cut back in temporarily at higher volumes but then put again soon after.

I initially thought the amp was the issue, but after switching the channels between the amp and pre amp, the faulty channel switched with it. So clearly the pre-amp is problematic.

Following this, I took the pre-amp appart and gave the inside a clean with some condensed air as it was covered in dust. Nothing obvious jumped out to me, but I'm not an expert.

This hasn't fixed the issue, I've ordered some Deoxit D5 to give the pots and switches a clean but not sure if this will sort it.

Any thoughts or suggestions are very welcome!!!

(NOTE: I'm not sure when it was last, or has ever, been serviced. The system was my grandfathers and he absolutely loves it to bits)

 

[jefferylhenr]

I would bet on the switches

 

[lpm123]

I would bet on the switches

Do you think a good clean with Deoxit would solve the issue?

 

[SaturationPt]

Yes.

You can cycle the switches to see if you hear a crackle and whether the channel cuts back in, also the balance and volume, input, stereo/mono/reverse knob, all of them are in the audio path. I’d say there’s a >90% chance that it is a switch or potentiometer causing your symptom.

Also ensure that the amp doesn’t get hot, I’ve read here of DC offset problems that will run it hot. My AU-11000A (the BA and CA combined in one unit) runs perfectly without anything other than occasional cycling of the switches and knobs but some do not. It is of course recommended that you undertake a complete restoration eventually.

Beautiful units, happy listening!