6060 repair

[kaplang]

I'm not at the house right now. Did you have to remove a fuse like the 9090 to adjust bias?

Didn’t remove any fuses.

 

[avionic]

Ohm's check those two emitter resistors that your testing across for your bias adjustment on the mess up side. R710 and R708 ( .33Ω )

 

[kaplang]

Ohm's check those two emitter resistors that your testing across for your bias adjustment on the mess up side. R710 and R708 ( .33Ω )

Did that. Both read .4 ohms. Something still going on the 7201. I was listening to it today and it went into protection mode after about 10 minutes of play. Stays their for a minute and then went out of protection and then back and forth indenfenitly. I’m fairly certain the biasing problem and it going in and out protection are related problems.

Question about turning on the 6060
Any receiver that I’ve owned with a protection circuit relay will start with full audio as soon as the relay clicks. This 6060s relay will click out of protection and then a few seconds later the receiver will slowly fade in the audio. Kind of like its warming up. Is that normal or just another problem I will need to troubleshoot? Never owned any Vintage Sansui so I don’t know what’s normal

Thanks

 

[avionic]

. Is that normal or just another problem I will need to troubleshoot?

No. Yes. Sounds like a power supply issue. Have you replaced all the caps yet? The two bigg'ns?

 

[kaplang]

No. Yes. Sounds like a power supply issue. Have you replaced all the caps yet? The two bigg'ns?

No caps replaced and I am trying to do the minimum to just get it working. A PS cap replacement may be in its future. I’ll have to give that some thought. I want to solve the protection problem first.

Thanks

 

[avionic]

. I want to solve the protection problem first.

The power supply issue may be the root cause for the protection issue.

 

[avionic]

First thing in t-shooting any electronics is a stable power supply.

 

[avionic]

Take a gander at the large caps bottom side. Look for any sign of venting. Shrunken plastic sleeves are a telltale sign of heat stress either internal or external.

 

[petehall347]

Just to see if one of the ouptputs blew I removed the output transistors for the right channel and tested them again. They both test good so I put them back in. The receiver then came out of protection mode and both channels now work. I actually don’t know why the right channel is now magically working. A bad connection to one of the output pins that resolved when I put back the outputs. Maybe! That’s the only thing I can think of. I am able to set the bias properly for the left channel but the right channel will not set. It stays at 0. I tried replacing the adjuster pots but it didn’t help. It sounds like the left channel is a little louder and slightly clearer then the right.


Thanks

maybe a good idea to check for poor solder connections . plus if outputs use insulators check those also .

 

[kaplang]

First thing in t-shooting any electronics is a stable power supply.

Good advice.

 

[kaplang]

I've decided to replace the power supply caps. I have looked for a thread that lists part numbers that I might find at mouser for equivalent caps. Didn't find anything that helps me. Can anyone recommend a part number for the 2 big main filter caps on the F2650 capacitor board. They are 6800 Mf 50 WV solder in caps.
Thanks
pictures of cap being replaced

 

[avionic]

Can anyone recommend a part number for the 2 big main filter caps on the F2650 capacitor board. They are 6800 Mf 50 WV solder in caps.

Diameter and length? An max length that you have to work with.

 

[LBPete]

50 volt is kind of an odd value and modern caps this size won't have three terminals. The third terminal is usually a dummy just to provide more stability. Here are a selection of 63V 6800mf audio grade caps.
https://www.mouser.com/Passive-Comp...hr0Z1yzvvqx?P=1z0wqtnZ1z0z80hZ1yx4avuZ1yztuat

The snap in choices will solder directly to your board. You may have to reposition the holes though. If you want to re-stuff those cans, use the radial caps: They should fit easily inside the cans.

You could also go with more capacity if you want. Here are a couple of 82mF snap in . https://www.mouser.com/Passive-Comp...s/_/N-75hqtZ1yzvvqx?P=1z0wqsnZ1yztuatZ1yx4avu

- Pete