R80/RA81 diagnostic experience?

From: Gooijen H <GOOI_at_oce.nl>
Date: Tue Mar 9 03:36:39 2004

I am not sure that removing the brake will help.
I once heard the following rumour:
the brake in combination with the 'heavy' motor
makes sure that the disk platters always rotate
in the same direction, never for a short instance
in the other direction (vibration, power flutter,
whatever reason). Rotation in the opposite direction,
for any short moment, will cause the air on which the
r/w head fly to disappear and result in an immediate
head crash ...

As I said, it is a rumour I once heard a few years ago.
Has anybody heard of this too?

  gd luck with your drive,
- Henk, PA8PDP

> -----Original Message-----
> From: Brad Parker [mailto:brad_at_heeltoe.com]
> Sent: dinsdag 9 maart 2004 2:50
> To: General Discussion: On-Topic and Off-Topic Posts
> Subject: Re: R80/RA81 diagnostic experience?
> >Tony Duell wrote:
> >>
> >>IIRC there's a microswitch which detects that the tensioner
> >>lever is in the 'tensioned' position, but nothing more. Of
> >>course the drive does check that the spindle is rotating at
> >>the right speed when it's spun up.
> I pulled the HDA - the belt tension switch was fine.
> I found, however, the electric brake was *extremely* tight. So much
> friction that I doubt very much the motor could spin at all.
> I removed it (I'll sand down the 'brake pad' later).
> Hoping for a small miracle I fired it back up but still no joy - the
> motor (now free) refused to spin up.
> [a side note: the unit does not seem to reset no power up -
> it comes up with all lights on until I click the reset manually.
> sometime tells me this is a symptom]
> I need some prints so I can trace the motor power back to the micro...
> Any have prints for an R80 (or RA80/RB80/RM80). Or an RA81?
> I suspect they are similar in terms of motor drive...
> -brad
Received on Tue Mar 09 2004 - 03:36:39 GMT

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