15 Jul
2004
15 Jul
'04
11:15 a.m.
Hi,
I have an old B&W "specialty" monitor which recently stopped working.
In the process of moving it around (to/from repair place) I noticed a
little black "tube magnet" dropping out when I took the cover off.
At the time I didn't think much of it (those in the know can chuckle now).
There are few, if any, unimportant components in monitors :-)
So, after a bout of replacing bad caps with no luck, I eventually broke
down and replaced the deflection board and the monitor sprang to life.
Much joy.
(note: "specialty" = designed for a specific computer with a special ECL
What machine?
video connection and has no standard connector or
interface. and no
schematics)
No schematics is not an excuse for not repairing things properly. I've
had to start with no schematics quite often (and by the end of the repair
I normally have my own set of scheamtics...)
So, monitor is working. I proceed to adjust the H & V size, linearity, etc...
I notice that the bottom and sides will square up nicely but the top
edge has a large "dip" in the middle. No amount of trimmer fiddling will
fix this.
light goes off. "found" tube magnet is part of yoke assembly.
Quite probably...
So, I notice where the missing magnet came from. Naturally it's on the
top side of the yoke assembly.
But - the "tube" has broken into 3 pieces (it was broke when I found it.
honest). I carefully glued it back together (no glue in the joints,
What glue did you use? Isocyano acryliic hydro-copolymerising adhesive is
probably the bsst for this becuase it's such a thin layer. Did you
carefully align the broken parts (so no gaps) when you stuck them together?
however) and replaced it. This helped a little but
did not cure the
problem.
[note to reader: I never took that fields course. I know nothing of magnets.]
So,
- is a broken magnet pushed back together not as good as a whole magnet?
(strength wise)
Should be, provided there are no gaps.
- can I get a new magnet somewhere?
Is this a monochrome monitor? If so, try expserimenting with other small
magnets. I don't think you can do much permanent harm.
-tony