Yamaha PX-2 Tonearm Tracking Issue

[lJelal]

This is not a request for belt flipping advice - not that issue. Since I have had this turntable, it never cued automatically and never had multiple advancement speeds in tonearm movement. I didn't care, I just used it manually and loved it.

My issue is the tonearm moves to the right (away from the spindle), but not to the left (towards the spindle) when using the manual buttons (4 & 7). It won't tracking records at all either as of a few days ago when my problem started.

While investigating I found something interesting. It seems my diode 34 may have been replaced with a jumper. Note the indention in the middle of the jumper. Not pristine like the other jumpers which are clearer marked as jumpers and pristine factory looking. I also found nothing installed in the D35 position. The schematics and parts list clearly have these listed as Diode PN: W06C but I just want to double check - anyone seen a board that looks anything like this?

Thanks.

 

[restorer-john]

This is not a request for belt flipping advice - not that issue. Since I have had this turntable, it never cued automatically and never had multiple advancement speeds in tonearm movement. I didn't care, I just used it manually and loved it.

My issue is the tonearm moves to the right (away from the spindle), but not to the left (towards the spindle) when using the manual buttons (4 & 7). It won't tracking records at all either as of a few days ago when my problem started.

While investigating I found something interesting. It seems my diode 34 may have been replaced with a jumper. Note the indention in the middle of the jumper. Not pristine like the other jumpers which are clearer marked as jumpers and pristine factory looking. I also found nothing installed in the D35 position. The schematics and parts list clearly have these listed as Diode PN: W06C but I just want to double check - anyone seen a board that looks anything like this?

Thanks.

The diodes were likely back to back to ensure the motor was not drawing current/trying to start when the output of the driver was not perfectly at 0V. The output of the comparator and driver would need to swing well above 0.6V in either direction for the motor to move and it also meant a cleaner stop.

I would look at the rear of the PCB- see if it's a mod- is there evidence of solder removal on the unistalled diode holes?

There's a whole lot going on with the arm travel controls and you'll need to work out exactly what is working and what isn't before digging in further. Does fast work and slow not?

Is the arm tracking correctly (moving in and out) when you play a record or lift the arm and move it a little left and right?

 

[lJelal]

I would look at the rear of the PCB- see if it's a mod- is there evidence of solder removal on the unistalled diode holes?

Does fast work and slow not?

Is the arm tracking correctly (moving in and out) when you play a record or lift the arm and move it a little left and right?

On the other side of the PCB, the jumper does not look factory - the joint on the left is especially suspicious.

Fast and slow have not worked since I have had the turntable.

The arm no longer tracks. It now stays stationary since the problem began.