TECH: Tube Swap and now one section of monitor won't degauss

barakawins

Well-known member

Donor 2023
Joined
Nov 14, 2004
Messages
2,708
Reaction score
240
Location
Woodcliff Lake, New Jersey
TECH: Tube Swap and now one section of monitor won't degauss

Swapped a tube recently in a Super Pacman. I can't get the lower right hand side of the screen to stay degaussed. I've been using a professional degausser to get the color to stabilize but it just won't stay. Any ideas why or how to fix this?
 
Most likely the yoke needs to be adjusted. Try moving it closer or further back. You can try tilting it too.
 
dont forgt to DEGAUSS after EVERY ADJUSTMENT.

usually if the yoke isnt quite right yeah youll get a weired spot . May have to use those rubber wedges to get it perfect.
 
I recently had the same problem on a WG4900 tube swap... Adjust the yoke in or out until the "bald spot" goes away. Adjust, Degauss, Repeat.
 
If it really really wont go good and its in one corner, it could be the tube has suffered a knock in its life and the shaddowmask inside the tube has become detached in one corner, this is difficult to actually prove, but it can happen especially if the old tube was fine and using the same yokes etc and it is still very bad on the new. It will change if one corner inside is detached as the tube warms up the electron beam warms the shaddowmask and it expands a little. other than that try and use powerfull magnets on the bellhousing and glue them there if it improves it.

Andrew
 
Last edited:
Back
Top Bottom