Msg: 6066 *Conference*

10-15-95 11:22:13

From: PAUL WHITING

To : RICHARD HANSON

Subj: REPLY TO MSG #6064 (IS MY PDD2 DYING?!)

Thanks Rick, very much. I know how busy you are, and I thought after posting  
this I shoulda put "all" in my header like I do on CompuServe so's not to  
single out the busy sysop for answers!
 
But you took the time for a helpful answer, and it is appreciated.
 
I've dissambled the drive twice, so this answer will be in two parts, once  
before your answer and once afterward:
 
part 1:
 
I disassembled the unit, and cleaned the head. Wasn't sure what it was at  
first, but it appears to be that small, white ceramic-like block _below_ the  
disk where the felt arm comes down on top of it. 
 
When I powered up the stepper motor would run for a long time, several  
seconds, whereas it used to just come on for a moment as if it was resetting  
itself. I noticed the stepper assembly was positioned such that it was about  
half-extended. So I took courage and hand-turned the axle so the stepper was  
back at the end of its extension (toward rear of chassis), and now it powers  
up like it used to. 
 
Then I cleaned the head again, carefully, using 95% isopropyl alchohol.
 
I was quite gentle with the unit but I may have knocked the low-battery LED  
loose. Maybe it was a cold solder joint. I carefully touched a soldering iron  
tip to it and re-anchored it, without applying excessive heat. Seems to me,  
however, it used to flicker on for just a moment when you hit the power switch
to let you know it was working. Now, oddly, it would only do that if I 
_touched_ the upper pigtail of the LED when I powered up! 
 
I did get it working for a while after all this, but then it began acting up  
again. Will next try your rubber band cleaning suggestion. 
 
part 2:
 
Disassembled unit again, cleaning the belt and pulleys. Did not oil as you  
suggested, because not sure I had right oil, and thought the movement seemed  
smooth anyway. 
 
Without putting the case on, I tried again... noticed a strange thing: the  
stepper assembly would only go about halfway across the diskette window. Maybe
that's why I was only getting partial files and corrupted files in transfers.  
Also tried formatting a disk, and noticed the stepper assembly creeping across
the window, formatting each track til it got about halfway. Then it kept  
trying to format that track, and eventually gave up and gave me an error msg.  
Tried cleaning the worm drive... seems there is some lubricant there, too, more
of a grease I guess. In cleaning I removed this lubricant, so maybe should  
re-lubricate that, too.
 
So, pardon the long msg, but it's looking to me more like the stepper  
assembly. If you'll tell me what sort of oil to use on the motor and pulley  
bearings, I'll go back and do that... but that wouldn't seem to have any  
effect on the stepper assembly travel, would it? Or maybe it would... dunno!
 
Thanks again, Rick, for all your help.
 
Regards,
 
... Paul