Monitor deflection magnets; what to do when one falls out & breaks?

From: Paul Koning <pkoning_at_equallogic.com>
Date: Thu Jul 15 09:26:09 2004

>>>>> "Brad" == Brad Parker <brad_at_heeltoe.com> writes:

 Brad> Hi,

 Brad> I have an old B&W "specialty" monitor which recently stopped
 Brad> working. In the process of moving it around (to/from repair
 Brad> place) I noticed a little black "tube magnet" dropping out when
 Brad> I took the cover off.
 Brad> So, I notice where the missing magnet came from. Naturally
 Brad> it's on the top side of the yoke assembly.

 Brad> But - the "tube" has broken into 3 pieces (it was broke when I
 Brad> found it. honest). I carefully glued it back together (no
 Brad> glue in the joints, however) and replaced it. This helped a
 Brad> little but did not cure the problem.

 Brad> [note to reader: I never took that fields course. I know
 Brad> nothing of magnets.]

 Brad> So,

 Brad> - is a broken magnet pushed back together not as good as a
 Brad> whole magnet? (strength wise)

 Brad> - can I get a new magnet somewhere?

 Brad> - is there anything special about these magnets?

It's probably not a magnet, but rather a ferrite core. You'd know the
difference putting the pieces together -- if you feel no attraction or
repulsion, it's not a permanent magnet.

A broken & repaired one is just fine so long as the gaps are tight.
If you create an airgap -- with or without glue -- that will change
the characteristics.

For a repair like that I'd consider the thin (not gap filling)
superglue.

 Brad> - do normal monitor repair guys just have a box of these laying
 Brad> around?

Maybe, but it wouldn't necessarily fit.

 Brad> - does this sort of thing happen all the time?

It's never happened to me...

As for the problem, I wonder if the issue is that the core is in the
wrong spot. It's part of the deflection magnetics assembly, and if
it's misplaced then you'd certainly get problems like you describe.
Take a look at the corresponding piece at the bottom of the yoke. I
would expect things to be symmetric. The fact that the thing fell out
suggests that it may have been out of position, and when you pushed it
back in you may not have gotten it back where it actually belongs.

     paul
Received on Thu Jul 15 2004 - 09:26:09 BST

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