RA81 spindle sensor

From: Jay West <jwest_at_classiccmp.org>
Date: Sun Jan 18 16:46:38 2004

I have 4 RA81's in a single rack (it's a VERY heavy rack), 3 of which are
marked "Bad HDA". Plus I have some others loose. So if Jules or anyone else
wants some parts scavenged from one of the ones marked "bad hda" just let me

----- Original Message -----
From: "Jules Richardson" <julesrichardsonuk_at_yahoo.co.uk>
To: <cctalk_at_classiccmp.org>
Sent: Sunday, January 18, 2004 5:41 AM
Subject: RA81 spindle sensor

> Ok, we took the HDA out of one of the RA81 drives yesterday. The
> bearings seem good - no excessive play - and we think the motor
> capacitor is fine. Some wear on the motor + HDA spindle pulleys, but the
> drive belt has a huge amount of grip so I don't think there's any belt
> slip problems.
> The front panel lights just indicate a "spin error", whilst the logic
> board status LEDs indicate a code of 01 - pointing at the spindle
> sensor.
> I made sure this was dust-free, but still no joy, so either it has gone
> bad or there's a fault with the logic board bolted to the top of the HDA
> itself (sensor seems more likely as we have two drives giving the same
> symptoms)
> The sensor appears to be optical in nature - with four wires (red,
> black, yellow and white).
> So:
> 1) Anyone know the connections to the device? If so we'll stick the
> output side on a 'scope next weekend and see if it outputs anything (of
> course we have no working unit to see what the waveform *should* look
> like, grr)
> 2) There are a couple of unknown-status RL01 and RL02 drives in store.
> Long shot, but anyone know if they use the same sensor in any part of
> their mechanism so we can do a temporary part swap with a (hopefully
> good) unit?
> 3) Anyone have a RA81 HDA in the UK that's suffered a head crash or
> other destruction and may yield a working sensor for us? :-)
> cheers
> Jules
Received on Sun Jan 18 2004 - 16:46:38 GMT

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