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Sansui ba-5000 bias test points help !

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xalara76

Active Member
Does anyone have an image of where to put DMM leads ? Looking at factory service manual and following what’s written gives me weird results, 106 volts !!!

Positive lead on red wire from terminal, and black lead on the pin from board right below it per channel.

What am I doing wrong ? Both channels show an equal 106v, it’s from my understanding this is to be set to 180Ma .. please help. Thanks
 
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Ok stupid me, I didn’t have my DMM plugged into the correct mA section. Now I test and get 0 mA on both left and right channels… what gives ?
 
I just posted in your thread in the solid state section....

"Ma as in amps? Are you sure the bias spec isnt in Mv, volts?" Im not familiar with that model but my AU20k bias is in Mv as well as most other Sansui & other brands Ive owned.
 
DEFTECHY said:
I just posted in your thread in the solid state section....

"Ma as in amps? Are you sure the bias spec isnt in Mv, volts?" Im not familiar with that model but my AU20k bias is in Mv as well as most other Sansui & other brands Ive owned.
Click to expand...
Yes, the service manual indicates to adjust to 180mA.

I originally had it set to DC volts and it gave me 106 volts (wrong)
 
DEFTECHY said:
I just posted in your thread in the solid state section....

"Ma as in amps? Are you sure the bias spec isnt in Mv, volts?" Im not familiar with that model but my AU20k bias is in Mv as well as most other Sansui & other brands Ive owned.
Click to expand...
I believe it’s because the BA5000 has autoformers
 
180 mA is the correct value, as described in the manual. Seems like you dont have your meter set up properly.

I advise you to be cautious when trying to take the measurement- the amp is ON. If the test lead accidentally slips off, you can very easily short out the amp
and it can go totally dead. I know this because it happened to me over 20 years ago. The good news is, once R733, a 3.9 ohm 10 watt resistor was replaced, the amp came back to life. Even back then, was not an easy to find component and someone I knew was able to supply me with one.
 
Are you removing a wire and putting your meter in series with the wire you removed and the lug it was removed from?

Rob
 
Robisme said:
Are you removing a wire and putting your meter in series with the wire you removed and the lug it was removed from?

Rob
Click to expand...
No I have not removed any wires. DMM fuse is good.

Am I supposed to remove any wires to then test ? I read somewhere the (+) wire from transformer is supposed to be removed but I didnt want to do so till 100% confirmation while doing this bias test.
 
Bright_Star said:
180 mA is the correct value, as described in the manual. Seems like you dont have your meter set up properly.

I advise you to be cautious when trying to take the measurement- the amp is ON. If the test lead accidentally slips off, you can very easily short out the amp
and it can go totally dead. I know this because it happened to me over 20 years ago. The good news is, once R733, a 3.9 ohm 10 watt resistor was replaced, the amp came back to life. Even back then, was not an easy to find component and someone I knew was able to supply me with one.
Click to expand...
I am plugging in the leads with it off, using alligator clips, then powering it on to test. I believe as rob stated, the positive cable should be unscrewed from the board and the negative can just be attached where it is. Then test with DMM ?
 
Hyperion said:
It does have Autoformers but that has nothing to do with bias setting. You probably have a blown multimeter fuse.
Click to expand...
Other testing confirms DMM works fine. I just don’t think I’m going the bias testing correctly. Am I supposed to remove the positive lead from the board to essentially test it out of circuit while the negative lead stays attached and then clipped with the negative test wire ?
 
OP, what was wrong with the advise we gave you in your other thread? You started two threads on the same amp an hour apart.
 
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