The repair saga's details (for those interested)
The following gives a step by step account of what I went through during the
repair of my MDS-S30 minidisc unit.
- July 2000: I inherited an MDS-S30 minidisc recorder deck from
my brother. He told me that it no longer ejected discs and that the AMS
rotary encoder was missing its knob; if I could fix it I could keep it.
Other commitments meant it was a few weeks before I could investigate
- August, September 2000: I addressed the problems with the unit in
spare time and by the beginning of September 2000, after some relatively
minor mechanical repairs to the front panel, repairing of a couple of dry
joints in the power supply and replacement of the rotary encoder, the deck
was back in working order.
- Mid-September 2000: While in use one day the deck suddenly
stopped recording. It would go through the motions of recording but on
playback the new recording was nowhere to be found. Playback of previously
recorded discs was fine. Because of the deck's age I did not want to take
the unit into a service centre and pay a quote fee only to be told that some
major component had failed, making repair uneconomical. (This seemed likely
since reports on the internet generally indicated that these symptoms were
due to a failure on the BD board which is uneconomic to repair for a deck of
this age.) Therefore, armed with the service manual of an MDS-JE510 I set
about determining what might have failed.
Although the MDS-JE510 differs substantially from the MDS-S30, the
descriptions and circuits in the former's manual gave sufficient detail to
deduce what should be occurring within the MDS-S30. I was able to determine
that the overwrite head definitely had its required signal and that the
laser was also being driven correctly by the electronics. This left two
possibilities: either the laser was not emitting correctly when switched to
`record' power, or there was a problem with the overwrite head itself. Upon
close inspection of the overwrite head in the `record' position it appeared
that it was not actually resting on the disc correctly, so I concluded that
a mechanical fault with the overwrite head was the most likely problem.
- 9 October 2000: Having determined that the replacement cost for
an overwrite head for this model is of the order of AU$75 I decided that a
repair would be economic, given the new price of comparable decks is around
AU$400. Lacking the necessary equipment to fully test either the laser or
the overwrite head in order to positively identify the faulty component, I
took the unit to Digital Domain - an Authorised Sony repair centre here in
Adelaide. I explained what I had found and that I suspected either a faulty
overwrite head or laser assembly.
- 12 October 2000: I was contacted by Digital Domain regarding the
repair. To my surprise I was told that `corrosion' had `caused damage to
all circuit boards' and that therefore repair was uneconomic. During my
repairs of the unit I had noted a white deposit in a few places within the
unit but after inspection had decided that it was harmless. I mentioned
this and was told I could talk to the technician about the details when I
came to pick the unit up.
- 16 October 2000 : I returned to Digital Domain to claim the unit.
Once again I expressed my surprise at the news. Despite what I was told
earlier I was not allowed to talk to the technician. A conversation with
with the manager was ineffective at convincing Digital Domain that perhaps a
reconsideration was warranted. With sincere doubts about their diagnosis I
reluctantly paid their quote fee (AU$55) and departed with the unit,
determined to investigate this supposed corrosion.
- Late October 2000: Within a short time I had discovered two things.
Firstly, when the unit was tested on arrival home, it failed to play discs
whereas playback functioned perfectly on 9 October 2000. Secondly, upon
removing the cover, the alleged corrosion turned out to be simply a
non-conducting white deposit which was easily wiped off with a cottonbud
dipped in methylated spirits - not even the circuit board lacquer was
damaged underneath. The extent of the deposit's distribution within the
unit did not appear to match the diagnosis given.
Once again, armed with the MDS-JE510 service manual I set about finding out
why playback no longer worked. The problem was traced to a microswitch (the
sled `limit in' switch) which had a broken lever. I found this very
surprising, knowing that there was no way this could have been broken in
transit and that playback worked fine on 9 October. Arrangements were made
to acquire a replacement switch.
- 5 January 2001: After an inexplicable delay, the microswitch
finally arrived on 5 January 2001.
- 8 January 2001: After fitting the new switch the unit was able to
playback correctly once more. With little to lose I decided to have a go at
manipulating the overwrite head back into a more likely looking position.
After about thirty minutes of trial and error I succeeded in restoring the
record function to the deck, proving beyond doubt that the cause of the
fault was indeed the overwrite head. Clearly the spring elements had
weakened over the years and a replacement was deemed necessary to guarantee
reliable operation. This was demonstrated in the weeks following this
- 29 January 2001: Ordered a replacement overwrite head from
Speedy Spares in Melbourne for a cost (including shipping) of AU$72.20.
- 5 February 2001: New overwrite head arrived and was fitted by
myself. Because the new unit was slightly longer than the original it caught
on some metalwork associated with the disk loading mechanism. The offending
metalwork was trimmed with a nibbling cutter. Correct operation of the
record function was then verified.
Note: The opinions and observations expressed on this page are those
of the author only.
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