[comp.sys.mac.hardware] Mac+ Monitor going bad

sandell@ferret.ils.nwu.edu (Greg Sandell) (03/10/91)

I have a 2 1/2 year old MacPlus and the screen is going bad, it seems.
Now and then the screen simply goes black.  When I give it a hit,
it comes back on, accompanied by some flicker and a bunch of thick
black bands across the screen.  I have Moire as my screensaver, so
if it was my screensaver kicking in, I would know it.  It's definitely
a monitor problem.

It seems to happen when I've left it on for a few hours.  I have a little
fan strategically pointed at the 'hot spot' (top front left edge) which
keeps it cool, so I tend to leave my Mac on for 3-4 hours at a time, sometimes
all day.

Some questions for anyone who knows the answers:

1) What's going bad and how much will it cost me?
2) How long before the screen dies bigtime?  (Currently the problem isn't
	very disturbing, very infrequent)
3) Any clue why the problem shows up only after the machine has been
	on for a few hours?

Thanks in advance,
Greg Sandell

--
****************************************************************
* Greg Sandell (sandell@ils.nwu.edu)          Evanston, IL USA *
* Institute for the Learning Sciences, Northwestern University *
****************************************************************

davisson@milton.u.washington.edu (Gordon Davisson) (03/14/91)

Oh, boy, I get to answer two questions at once!

In article <1096@anaxagoras.ils.nwu.edu> sandell@ferret.ils.nwu.edu
(Greg Sandell) writes:
>I have a 2 1/2 year old MacPlus and the screen is going bad, it seems.
>Now and then the screen simply goes black.  When I give it a hit,
>it comes back on, accompanied by some flicker and a bunch of thick
>black bands across the screen.

And in article <1991Mar9.194446.8378@contact.uucp> jkirsh@contact.uucp
(Joel Kirsh) writes:
:My almost-two-year-old Mac plus has recently developed intermittent "black-
:outs" (maybe I should be crossposting to sci.med? ;-) )
:
:The entire display goes black, but returns with just a slight tap of the
:casing.  Anyone seen this before?  Is it my entire display that's trashed,
:or just a flakey connection here or there?  Am I about to be electrocuted
:by an improperly connected flyback transformer?

Both of you are almost certainly sufering the same problem: a cracked
solder joint on pin 1 of the J4 connector on the analog board.  (It's
the 10-pin connector near the middle of the analog board.  Pin 1 is the
one at the end closest to the front of the Mac, a little seperated from
the other pins.  The function of that pin is to carry the video signal
coming up from the motherboard.)  All you should need to do to repair
it is heat the connection with a soldering iron, and maybe add a little
more solder.  As long as you're at it, you might as well redo the rest
of the pins, and also those on J1 (the 4-pin connector near the top front
corner of the board).  If you don't feel up to doing it yourself and
there's no one in your area who does this sort or work, mail it to me;
I like easy repairs.

--
Gordon Davisson
Westwind Computing	(206) 632-8141
4518 University Way NE, Suite 313, Seattle WA 98105

omh@cs.brown.edu (Owen M. Hartnett) (03/15/91)

That advice is fairly good, except that you shouldn't just reheat the
old solder, you should *remove* the old solder with a desoldering tool
(radio shack horribly colored blue/yellow vacuum pump) and completely
resolder the pins, otherwise it happens again.

-Owen

Owen Hartnett				omh@cs.brown.edu.CSNET
Brown University Computer Science	omh@cs.brown.edu
					uunet!brunix!omh
"Don't wait up for me tonight because I won't be home for a month."