EME-150A : broken track 0 detection ?

[reno]

Hi,

I have an EME-150A that stopped working while I was testing it with my Greaseweazle device. For those of you who have Facebook, I initially asked for help in the GW group here where you can see a video with the drive moving.
 
The main problem I think is the head assembly moving too far back whether I ask it to seek to track 0 or 40 (yes, it seems to move to the back either way !) and never stopping, making a loud grinding noise when it reaches the end.
The GW software has a disk "clean" function that seeks to random tracks, and it complained with messages like :

Code Select Expand

Pass 0: 9 0 19 10 29 20 39 30 49 40 59 50 69 60 79 70
Pass 1: 9 ** FATAL ERROR:
Track0 signal asserted after seek to cylinder 9


Code Select Expand

Pass 0: 4 0 ** FATAL ERROR:
Track0 signal absent after seek to cylinder 0
I have no idea where the track 0 sensor is on an EME-150A, everything I can find is about the EME-156.
I've changed the belt on this drive, lubricated the step motor worm and cleaned the head, that's about it.
It DID work for a while after.

I have another working EME-150A, and one difference I noticed is that, when moving the black ring around the worm screw to manually move the head, this happens in steps in the working drive, whereas on the broken one it's a continuous movement. Is that another clue ?

Any ideas welcome, thanks ! 

[Kris]

Hello,

I got he same issue in the past and I detected that the black ring was slightly cracked, you may have the same problem.

[reno]

Hello,

I can't remember what happened with this drive since I posted last year, but I have the same problem with another EME-150A.
Drilling noise when going to track 0 (driven by a Greaseweazle), and if I turn the black plastic "collar" around the worm screw manually, this is how far the head assembly goes in the other direction (towards track 40) : clearly not far enough I suppose ? The whole mechanism acts like it's shifted towards the back, is that possible ?

How do you fix track 0 sensor issues in general ? Sorry if this is a FAQ but I couldn't find anything here.

[reno]

Hello,

Does anyone have any ideas ? I'm stumped 

[Rabs]

Hello,

Does anyone have any ideas ? I'm stumped 

I may have a similar issue with a drive, almost like the stepper motor is not stopping at the end of travel.

Out of interest what does the highlighted component do? Does this detect the end of travel?

You cannot view this attachment.

[darkhalf]

Try adjusting track position gradually (track by track) either in GW on using disc utility on the CPC. See if you can move the motor that way

IIRC there is a light sensor for when the head moves to track 0