RD54 Stopped Spinning

Johnny Billquist bqt at update.uu.se
Fri Apr 3 08:17:44 CDT 2015

On 2015-04-03 09:58, Robert Jarratt wrote:
> Bit of an update. I put the transistors back as they seem to be OK and
> applied power to see if probing around would show anything. The Z8 was
> getting power, and the transistors did heat up within a few seconds, but the
> disk did not spin at all.  Is this going to be a problem with the motor
> itself?

Brushes of the motor (if they have them) would be one thing to check.
Check if the motor is getting power?


> On a side note, I spotted a component which I can't identify, folded down
> above the Z8 and stuck to what looks like an adhesive pad on the PCB. The
> can looks a bit mottled/corroded. On another non-working RD54 it seems to be
> marked "12039". I am not sure what this component is, although it looks like
> it could be a capacitor. Anyone know what this might be?
> Regards
> Rob
>> -----Original Message-----
>> From: cctalk [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Robert
>> Jarratt
>> Sent: 02 April 2015 23:19
>> To: General Discussion: On-Topic and Off-Topic Posts
>> Subject: RD54 Stopped Spinning
>> The other day my RD54 just stopped rotating, dead in its tracks, while it
> was
>> running. I guessed one of the motor control power transistors may have
> failed. I
>> assume they are the series of 6 chunky ones attached to a single heatsink.
> I
>> have desoldered them (en-masse) and tested them with a Peak
>> DCA55 tester, and they all appear to be working. Does anyone have any
> other
>> suggestions? Has anyone ever repaired an RD54 control board?
>> Regards
>> Rob

Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol

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