Hi everyone, This is now the fourth DD Walkman I've fixed up, and after replacing the center gear, REW gear and replacing the caps I'm very close to finishing this one. The only problem is that the pinch roller keeps pulling the tape toward the inner side of the compartment. Thinking it was a bad pinch roller, I replaced that part but no change at all. I also swapped in another capstan just to see if that makes a difference, same problem. Looking at the roller when it pushes against the capstan, there does appear to be a very slight tilt, but I've noticed this on working units too, and I've never had this problem on any of the other DDs I've worked on (until now I've had good luck with very low W&F and steady tape travel). I've ordered some FeCl3 to resurface the capstans. Is there anything else I can adjust? I'm a bit stumped with this one, so any tips would be appreciated.
There are 3 things to be considered: 1. the roller tilt; I know in many units this won't create a problem, but it's something worth adressing as it wil wear the tape unevenly even if it's not creating any tape path problems. 2. etch the capstan with FeCl3, to eliminate potential uneven wear/polish. 3. if none of the above fixes the problem, you will have to change the angle of the capstan by adding shims under the FG coil plate; Problem is most likely caused by point 3, but the other 2 are worth doing also.
Hi Valentin, thanks for the tip. I tried putting a small piece of electrical tape under one side of the FG coil. I think this is helping, but will need to keep testing to be sure.
I have figured out the tape path issue, ended up taking the pinch roller arm and gently twisting it to get the proper angle on the roller axle. I had taken out the shims from under the FG coil, as I was getting a lot of flutter, and it seemed like the motor wasn't generating the usual amount of torque. Turns out that this is probably a separate issue, as the flutter is still there, and I can hear an abnormal rhythmic whirring sound from the motor. I haven't encountered this before, but I have a feeling there is something going on electrically with the speed control. Has anyone dealt with this before?
Regarding the flutter issue, recommend reading this thread: https://stereo2go.com/forums/threads/sony-wm-dd33-speed-issues-and-more.9456/page-2#post-86397 First thing to try is desolder the PLL bridge and see if this problem goes away. Adjustment trimpot settings that are clsoe to min/max can cause very high flutter.
Ah interesting, yes, I'm familiar with this thread, but I was hoping this wouldn't happen to me - haha. DD22's are plentiful and inexpensive on local listings here in Germany, so, if needed, I should be able to source a replacement servo IC without too much trouble.
