[net.micro.mac] Macfailures

ward@hao.UUCP (Mike Ward) (06/03/85)

[]
Our Engineering & Maintenance Group has recently encountered
a rash of Macs with burnt-out video boards.  We have been able
to determine that the problem we are seeing is the most common
cause of macintosh failure - at least in the Boulder area.

It is the opinion of our engineers that a driver transistor in
the horizontal retrace circuitry is under-powered or under heat-sinked
or both.  This transistor apparently opens or shorts and takes
out one or more other componants, the most common being a capacitor
or the flyback transformer.  When the Macs we saw failed, they
failed in a spectacular manner with lots of smoke and big stink.
In at least one case, the Mac was still running in spite of the
smoke when it was powered off.

Even though Apple recommends in the Macintosh manual that the
Mac be left on at all times, we feel that this is a very dangerous
thing to do.  Since the Macintosh is prone to pyrotecnic failure
without warning, it should never be left powered on unless it
is under supervision.

Apple has been notified of this problem, and has shown no sign
of caring.  Several people have returned burnt Macs to dealers,
and two that I know of have have the problem repaired without
cost after the warranty had expired - one happily, with no questions
asked; the other only after threatening legal action (ala consumer
fraud) and all sorts of nasty things.

In addition to leaving your Mac turned off. it would be a good
idea to buy Applecare health insurance.  The Macintosh is not
even getting close to the two percent failure rate that they
boast about.

lesgold@cadre.ARPA (Alan Lesgold) (06/03/85)

In article <1569@hao.UUCP> ward@hao.UUCP (Mike Ward) writes:
>[]
>Our Engineering & Maintenance Group has recently encountered
>a rash of Macs with burnt-out video boards. ... 

On one of mine, the set of wirings going to the deflection yoke was resting
on the heat sink you mentioned and eventually the insulation melted, producing
the results you described (smoked video board.  I'm tempted to suggest that
advance addition of appropriate tape on those wires would solve the problem.
--Alan Lesgold, U of Pittsburgh

hkr4627@acf4.UUCP (Hedley K. J. Rainnie) (06/05/85)

Here, here! I agree totally. After 2 burned out Analog boards during continuous
i.e. >1month on use. I must echo not only my voice but those of the service
person "don't believe apple I recommend you use the machine when you need it,
don't leave it on all the time..." He has seen many more burn outs than I.
I now use a muffin fan pulling air out of the unit and I switch it off after
use. Sad to say the screensave programs won't be of any use to me anymore,.
Unless a new supply comes out......

		The analog board SUCKS!!!!

			Hedley Rainnie.