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New to me "Sansui 8" -need help

I found the speaker relay, on the bottom side-upside down. So the balance adjusment is the DC offset adjusment? Why didn't they just say that, I wonder? With this amp it says I need a 8ohm or 16 ohm load resistor parallel off the speaker jack when using the DMM to check DC volatage, is that correct? Where do I get one if I need it? Radio shack?

With the Current adjusment it refers to TP803 and TP801, I have not found those pins on the schematic at all.
 
I tried to jump the preamp L to mainamp R, couldn't do it, it seems its wired internally aside from the factory jumpers. Tapped on the speaker relay, no change.
 
Majoryyz said:
I found the speaker relay, on the bottom side-upside down. So the balance adjusment is the DC offset adjusment? Why didn't they just say that, I wonder? With this amp it says I need a 8ohm or 16 ohm load resistor parallel off the speaker jack when using the DMM to check DC volatage, is that correct? Where do I get one if I need it? Radio shack?

With the Current adjusment it refers to TP803 and TP801, I have not found those pins on the schematic at all.
Click to expand...

I'm hoping you guys continue providing me answers and tell me what to look for next. I'm stuck at the Balance Adjusment and Current adjusment until I can find out about pins TP801 & 803. If the headphones are supplied with current from the speakers, is power coming from the main amps(remember I found a blown fuse on the R channel)or from the preamp/Tone board? Would the speaker relay be stuck on the right channel, not allowing power to the speakers? I raise these questions to learn from what I know so far.
 
I noticed if this is anything, when I turned off the reciever I get a little pop in the right channel, not the left-is that anything?
 
Majoryyz said:
I found the speaker relay, on the bottom side-upside down. So the balance adjusment is the DC offset adjusment? Why didn't they just say that, I wonder? With this amp it says I need a 8ohm or 16 ohm load resistor parallel off the speaker jack when using the DMM to check DC volatage, is that correct? Where do I get one if I need it? Radio shack?

With the Current adjusment it refers to TP803 and TP801, I have not found those pins on the schematic at all.
Click to expand...

Look at the board layout for the driver board. TP803 and TP801 are shown there. You do not need the load resistors.
 
Thanks Dr. On the driver block there are no TP's but TR's and they're transistors(large round silver 3 pin) page 16 says place voltmeter to TR803 + side and TR801 - side. This doesn't make sense to me meaning you have Base-Conductor-Emitter. If this is correct which is + & -?
 
My manual shows the test points.
 

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Explain to me on the directions to adjust the current on the differental amp. Steps 4-6 mentions (V21) & (V31) What is this referring to? I want to understand everything before making any changes. remember I'm new to all this but i feel I can handle it when I have all the info digested. Thanks, Doc.
 
Majoryyz said:
Explain to me on the directions to adjust the current on the differental amp. Steps 4-6 mentions (V21) & (V31) What is this referring to? I want to understand everything before making any changes. remember I'm new to all this but i feel I can handle it when I have all the info digested. Thanks, Doc.
Click to expand...

Don't use alligator clips, you could short something out. Use these:
http://www.mcmelectronics.com/product/POMONA-3782-36-2-/201-016

V21 etc just refers to the measurement itself, just read the voltage on your DMM.
 
Here are my readings:
Balance Adj.
Left 11.9mv
Right 11.4mv
Could not bring it any lower

Current Adj.
By Steps from Sm
Left channel
(4) AC 013.8mv
(5) AC 013.7mv
(6,7) AC 014.0mv

Right channel
(4) AC 003.0mv
(5) AC 003.0mv
(6,7) AC 003.0mv

As I made the adjustments on each channel the speaker relay click on and then off. I couldn't get much change when I turned the VR trim pots as step 4 showed. The reading remained the same after it settled.
 
Tonight I checked the driver block boards F-1278 to make sure they are identical, they are , so I switched them R to L, L to R to check if there was any difference. There was not. That I believe elimates the driver boards, at least the right channel driver block being the problem. The other factor could be a bad volume pot?? Is that possible since its a dual unit and even after I deoxit it, it may just be bad. How can I check that to be sure? What does the driver block connect to next? I see the power block in the SM but I would think that's the power supply to the unit. Just seeking for answers
 
I'll give you a bump on this one. I'm fascinated. Hope you get it straightened-out soon. A+ for effort for sure so far. You're certainly-getting your hands dirty. Maybe it will just turn out to be one of those "Doh!" situations where the problem was staring you in the face the whole time.

And I'd love to see some pictures once you get 'er up and mobile (if yer' able to do the picture-posting thing). I'd love to have an 8 myself.
 
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Thanks! I'm just iching to jump in as soon as I know where to jump and get this fixed. The reciever is very clean inside, the left channel is real strong. I'm hoping Dr*Audio will chime in asap. he's been a great help.:yes:
 
For the current adjust the meter must be on DC Volts, NOT AC.
The fact that you could swap the driver boards and the bad channel didn't move verifies the driver boards are ok, but you have to re-do the current adjust. To find where the signal is being dropped, you really need an oscilloscope or an audio generator.
http://www.mcmelectronics.com/product/TENMA-72-505-/72-505

Majoryyz said:
Here are my readings:
Balance Adj.
Left 11.9mv
Right 11.4mv
Could not bring it any lower

Current Adj.
By Steps from Sm
Left channel
(4) AC 013.8mv
(5) AC 013.7mv
(6,7) AC 014.0mv

Right channel
(4) AC 003.0mv
(5) AC 003.0mv
(6,7) AC 003.0mv

As I made the adjustments on each channel the speaker relay click on and then off. I couldn't get much change when I turned the VR trim pots as step 4 showed. The reading remained the same after it settled.
Click to expand...
 
Here are the correct readings in DC
Balance Right channel 0.3mv
Left channel 0.0mv
thats after adjusting V801

Current Left channel (4) 001.7mv
(5) 0.615v
(6,7) 0.610v
Right channel (4) 001.5 mv
(5) 0.613v
(6,7) 0.593v

After finishing with the right channel, as I was doing the left channel the speaker relay was clicking on and off. So I attempted to get done quick and shut it off.
 
I don't think you are performing this adjustment correctly. You should have a voltage close to 0.5V for number 4. The object is to get the voltage from TP802 - TP801, and from TP803 - TP801 to be the same, close to 0.5V.
 
dr*audio said:
I don't think you are performing this adjustment correctly. You should have a voltage close to 0.5V for number 4. The object is to get the voltage from TP802 - TP801, and from TP803 - TP801 to be the same, close to 0.5V.
Click to expand...

I know that's what it says on paper but I turn it with very little movement on V802 and it swings quickly into the negative or up into 10.0 + mv I could barely get the 2 V802 readings
 
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