SX 626 radio side issues.

[Stereoboy70]

Are you tracing a signal with the scope to the meter board, then out of the meter board to switch S2? And then onwards from the switch to the inputs to the EQ board?

From there the signal goes through the EQ board to the switch assembly board.

After that it goes through the volume and balance controls, but we know that part is working.

View attachment 3003447

Traced a good signal to the EQ board. Seems to drop off on the EQ board output.

 

[kwayde]

Traced a good signal to the EQ board. Seems to drop off on the EQ board output.

Very good. That board has four transistors which are on the crap list that should be changed out with new replacements. Since they should be replaced, replace them to see if the signal will then pass through.

In the first post you stated the phono section was working good so I don't know why FM wouldn't work if the phono was working. Unless the signal was dropping off before it gets to the EQ board, like somewhere in the switch contacts/wiring.

You can use ksc1845's for all of them. Pay attention to pinouts.

 

[Stereoboy70]

Very good. That board has four transistors which are on the crap list that should be changed out with new replacements. Since they should be replaced, replace them to see if the signal will then pass through.

In the first post you stated the phono section was working good so I don't know why FM wouldn't work if the phono was working. Unless the signal was dropping off before it gets to the EQ board, like somewhere in the switch contacts/wiring.

You can use ksc1845's for all of them. Pay attention to pinouts.

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View attachment 3004046

I replaced the 4 -1312 transistors with 1845’s. Still low volume. I’m going to recheck the Phono inputs and see if the volume changes. My aux input from a BT adapter is fine. Volume is good.

 

[Stereoboy70]

Very good. That board has four transistors which are on the crap list that should be changed out with new replacements. Since they should be replaced, replace them to see if the signal will then pass through.

In the first post you stated the phono section was working good so I don't know why FM wouldn't work if the phono was working. Unless the signal was dropping off before it gets to the EQ board, like somewhere in the switch contacts/wiring.

You can use ksc1845's for all of them. Pay attention to pinouts.

View attachment 3004128



View attachment 3004046

Apologies. My phono inputs are also very low volume. I must have confused these with another receiver I was working on. Volume all the way up and hardly any sound.

 

[Stereoboy70]

Apologies. My phono inputs are also very low volume. I must have confused these with another receiver I was working on. Volume all the way up and hardly any sound.

I feel it either in the EQ amp or the switch board for the tape etc…

 

[Stereoboy70]

I feel it either in the EQ amp or the switch board for the tape etc…

FYi …the volume takes about 5-6 seconds until you can hear it at all. It almost seems like a cap issue.

 

[Stereoboy70]

Very good. That board has four transistors which are on the crap list that should be changed out with new replacements. Since they should be replaced, replace them to see if the signal will then pass through.

In the first post you stated the phono section was working good so I don't know why FM wouldn't work if the phono was working. Unless the signal was dropping off before it gets to the EQ board, like somewhere in the switch contacts/wiring.

You can use ksc1845's for all of them. Pay attention to pinouts.

View attachment 3004128



View attachment 3004046

I jumpered around the EQ board, selector switches and switch boards directly to the volume pots. Very good volume. I’ll continue my troubleshooting.