[comp.sys.mac.hardware] Apple RGB Monitor Problem

GAUJCT@latvax8.lat.oz (08/18/90)

I have an Apple RGB monitor (nearly 2 year's old) which periodically refuses
to power on.  The indicator light blinks momentarily when power is applied
and then remains off.  It appears that there is some protection circuit
coming into operation.  Other similar monitors on campus have also shown this
behaviour, but because it is extremely random we have not yet tracked down the
source of the fault.  Yesterday my monitor did not want to operate at all and
in desperation I arranged to send it off to Apple to be repaired.  We had
swapped the power supply with a working unit and that did not solve the
problem.  This morning it was working as if nothing had happened.  Any
information as to what could be the likely cause would be greatly appreciated.

John Traeger
Chemistry Dept.,
La Trobe University,
Victoria, AUSTRALIA
(E-mail: GAUJCT@LATVAX8.LAT.OZ)

fdm@WLV.IMSD.CONTEL.COM (Frank D. Malczewski) (08/20/90)

In article <4602@latvax8.lat.oz> GAUJCT@latvax8.lat.oz writes:
>I have an Apple RGB monitor (nearly 2 year's old) which periodically refuses
>to power on.  The indicator light blinks momentarily when power is applied
>and then remains off.  It appears that there is some protection circuit
>coming into operation.  Other similar monitors on campus have also shown this
>behaviour, but because it is extremely random we have not yet tracked down the
>source of the fault.  Yesterday my monitor did not want to operate at all and
>in desperation I arranged to send it off to Apple to be repaired.  We had
>swapped the power supply with a working unit and that did not solve the
>problem.  This morning it was working as if nothing had happened.  Any
>information as to what could be the likely cause would be greatly appreciated.
>
>John Traeger
>Chemistry Dept.,
>La Trobe University,
>Victoria, AUSTRALIA
>(E-mail: GAUJCT@LATVAX8.LAT.OZ)

This question is starting to earn its place on a Macintosh "most frequently
asked questions" list.  If anybody has exact details about just what the
problem is, I would be more than happy to reply to any and all subsequent
posts, after I got my monitor fixed as well.  This problem is quite annoying,
and seems to occur when my monitor passes some not-very-well-defined
temperature threshold.  Usually, once the monitor warms up beyond this
point, it is fine.  Sometimes, getting beyond the temperature point takes
quite a while, with the monitor being unusable for hours; othertimes, it
takes no more than a few seconds to pass this "threshold".

Just what is the problem here?  What can I tell my dealer?  The problem does
not happen to me unless it has gotten pretty cool overnight, but does not
consistently happen even then.  I know I'd like to get this fixed, as I can
just see the monitor finally failing when I am most in need of it...

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--Frank Malczewski                        (fdm@wlv.imsd.contel.com)
					  (malczews@nunki.usc.edu)

jsurine@entec.Wichita.NCR.COM (James Surine) (08/21/90)

In article <4602@latvax8.lat.oz> GAUJCT@latvax8.lat.oz writes:
>I have an Apple RGB monitor (nearly 2 year's old) which periodically refuses
>to power on.  The indicator light blinks momentarily when power is applied
>and then remains off.  It appears that there is some protection circuit
...
>problem.  This morning it was working as if nothing had happened.  Any
>information as to what could be the likely cause would be greatly appreciated.

>John Traeger

Temperature might be the problem. Are the monitors in the sun in the afternoon
Is the room the monitor is in get hot? etc...



-- 
                                         ____________________________________
j.surine@Wichita.NCR.COM (Jim Surine)   |                                    |
NCR Peripheral Products Division        |        | 
work (316)636-8586 home (316)721-6280  /_____________________________________|

GAUJCT@latvax8.lat.oz (08/29/90)

In article <660@entec.Wichita.NCR.COM>, jsurine@entec.Wichita.NCR.COM (James Surine) writes:
> In article <4602@latvax8.lat.oz> GAUJCT@latvax8.lat.oz writes:
>>I have an Apple RGB monitor (nearly 2 year's old) which periodically refuses
>>to power on.  The indicator light blinks momentarily when power is applied
>>and then remains off.  It appears that there is some protection circuit
> ....
>>problem.  This morning it was working as if nothing had happened.  Any
>>information as to what could be the likely cause would be greatly appreciated.
> 
> 
> Temperature might be the problem. Are the monitors in the sun in the afternoon
> Is the room the monitor is in get hot? etc...

It happened again this morning.  No monitor following power on.  However, the
usual trick of changing the monitor power supply from the IIcx computer outlet
directly to the mains worked.  This did not work previously so I don't think
that the problem is external to the monitor.  The temperature and humidity in my
office are relatively constant, so these don't appear to be the cause either.
Once the monitor is going it will not misbehave again during the day, no matter
how often it is turned off and on.

John Traeger