Degaussing wand

"JERD"



**  WES Components in Ashfield sell them.

 But any repair shop would have one -  so why not take the darn thing to one
?




......   Phil

  Not sure where you're located, but WES (Wagner Electronic Services) in
Ashfield, NSW has them.

put finger to keyboard and composed:



The trade price for a degaussing wand is around $80.

If your job is a one-off thing, then I'd try disconnecting the
monitor's degaussing coil and hooking it up to 240V via a series 100W
incandescent lamp, or two such lamps in parallel.

You could also try some of these tricks:
 http://www.wikihow.com/Degauss-a-Computer-Monitor
 http://www.repairfaq.org/sam/crtfaq.htm#crtucd

- Franc Zabkar

At some point you have to switch that jig off, if that happens at any point
other than zero crossing it leaves a magnetic polarisation on the
shadowmask, what I use is a degauss coil from a scrap monitor and a variac,
the variac should be carefully turned up until the coil held close to the
screen produces strong visible distortion and moved around to disperse the
magnetisation, then either slowly withdraw the coil away from the screen or
slowly turn down the variac, after that the picture should be OK.

put finger to keyboard and composed:



You're right. Sorry.



I suspect the OP is asking about a one-off job, in which case a variac
may be too expensive.
 


What about wiring an on/off switch across the PTC and adding a lamp
load between the PCB's degaussing coil connector and the coil itself?

- Franc Zabkar

A good alternative is to find a suitable power resistor to put in series
with a salvaged coil, the important thing is that the magnetic field is
reduced slowly as can be done by moving the coil away.


If the rogue magnetisation isn't too severe, possibly a simpler tactic would
be temporarily wire a second posistor in parallel with the one on the PCB,
its likely that the mains fuse will also have to be temporarily upgraded.
There is one significant risk to avoid, the common 3-pin posistors usually
have 2 PTC elements - the one in series with the degauss coil and a second
directly across the mains to heat the first above it's knee temperature.
Some manufacturers (especially Philips) occasionally use PTC/NTC parts, the
usual PTC in series with the coil plus a NTC in series with the mains feed
to the rectifier, any salvaged posistor should be checked for both PTC
(unless the original itself is PTC/NTC). It might take several goes and the
posistors take about 6 minutes to cool down each time.

You will have to leave the monitor off for some time between attempts
(say 10 minutes.)  If the monitor is one that you can disconnect the
mains, then reconnect it and monitor will turn on without needing the
power button pressed, you could buy one of those cheap mechanical
appliance timers from bunnings for under $10, set it to turn on for 15
min then off for 15 min repeatedly and leave it run the monitor
overnight)

In my experience, especially with severe distortion (that sounds like
what you have there) a degaussing wand is the way to go, however with
the end of CRT technology in sight, it will be something you have no
use for in the future.

Here are a couple of sources that might end up cheaper than the WES
one mentioned elsewhere.  A degaussing wand will do the job much
better/faster than the inbuilt  coil every time in my experience.

http://cgi.ebay.com.au/Degaussing-Wand_W0QQitemZ280159053941QQihZ018QQcategoryZ3320QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
http://cgi.ebay.com.au/BRAND-NEW-240V-DEGAUSSING-WAND-FOR-ARCADE-MACHINES_W0QQitemZ250171701751QQihZ015QQcategoryZ13718QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Even better - here is one for $25 !  (+$5 postage)
I dont think you will do better than that anywhere.

http://cgi.ebay.com.au/Degauss-Wand-240-Volt-for-use-with-Arcade-monitors-TV_W0QQitemZ170153872431QQihZ007QQcategoryZ3945QQssPageNameZWDVWQQrdZ1QQcmdZViewItem