Sanyo M-X920K restoration. Help desperately needed...

My M-X920 needs restoration.

It's clean. I finally got it to properly record from LINE IN without consistent buzzing, but recording quality in general still is not so great. Still buzzing a little from time to time when ALC is on or during the recording process only when carrying, or moving it but it records fine when the unit is sitting still now. It still makes a single VERY LOUD pop in the left speaker when I flip the ALC switch, or press record. I cleaned all contacts and got the static out of most the controls, but I can't seem to get the static out of the balance control when I bring it over to the left channel. The VU indicator always shows an imbalance of channels. Now all of the sudden the Noise Reduction LED indicator stays lit sometimes even when it's turned off and pause LED indicator stays lit when using any of the tape functions. Not sure what's causing all of this as of yet. I have a service manual. I am determined to get this thing restored.

Did you completely remove the frame from unit in order to get to all pots and switches too?


Bad Boy Bill

baddboybill said:

Did you completely remove the frame from unit in order to get to all pots and switches too?


Bad Boy Bill

Click to expand...

I had the entire unit disassembled.

the record bar could be dirty , press record and stop several times in a row letting it play for a few seconds before pressing stop each time. i also think there may be some dead spots in the controls so you might want to clean them again ,when cleaning the controls you need to work them up down back and forth and so on spraying into the openings with the controls in different positions , this allows the cleaner to be evenly distributed.also check for loose solder joints and wobbly controls.

My M-X920 needs restoration.

It's clean. I finally got it to properly record from LINE IN without consistent buzzing, but recording quality in general still is not so great. Still buzzing a little from time to time when ALC is on or during the recording process only when carrying, or moving it but it records fine when the unit is sitting still now. It still makes a single VERY LOUD pop in the left speaker when I flip the ALC switch, or press record. I cleaned all contacts and got the static out of most the controls, but I can't seem to get the static out of the balance control when I bring it over to the left channel. The VU indicator always shows an imbalance of channels. Now all of the sudden the Noise Reduction LED indicator stays lit sometimes even when it's turned off and pause LED indicator stays lit when using any of the tape functions. Not sure what's causing all of this as of yet. I have a service manual. I am determined to get this thing restored.


Most likely the reason LEDs are on is because cleaner has not dried and causing switch leads inside to have contact. A blow dryer could help it to dry inside switch better . You don't need a lot of cleaner sprayed into switch.


Bad Boy Bill

I'm not saying it's fully fixed, but guess what just now happened. I was moving the unit around and it was buzzing away like usual, then I decided to turn the unit completely upside-down to see what happens and all of the sudden, I heard high pitched buzzing noise come from the speaker and the buzzing just stopped dead. I then recorded over and it was perfect. No buzzing, no nothing. It sounded great! Now I know how amazing the recording quality on this unit really is. The NR light also functions as it should now.

The bad: The ALC's still a bit noisy when switched on, but not as bad as before. PAUSE LED light still stays on when tape isn't paused.

I'm not saying it's fully fixed, but guess what just now happened. I was moving the unit around and it was buzzing away like usual, then I decided to turn the unit completely upside-down to see what happens and all of the sudden, I heard high pitched buzzing noise come from the speaker and the buzzing just stopped dead. I then recorded over and it was perfect. No buzzing, no nothing. It sounded great! Now I know how amazing the recording quality on this unit really is. The NR light also functions as it should now.

The bad: The ALC's still a bit noisy when switched on, but not as bad as before. PAUSE LED light still stays on when tape isn't paused.


ALC switch probably still a little dirty. Pause led could be micro switch. Try pressing and depressing pause a bunch of times to see if it releases. As for buzzing and such maybe turning upside down the fluid in switches was able to rinse away dirt or something causing the bad connection. But there may be a possibility the buzzing returns


Bad Boy Bill