Cap Kit or Flyback - How do you know?

[RayB]

What's a Flyback?
How do you know whether a monitor needs just a cap kit, or a whole new flyback (whatever that is)?

 

Newbie for a Day

[SirPeale]

Cap kits are generally a given; if you've just received a monitor, and don't know for sure about a recent kit, do one.

Flybacks, IIRC, are pretty evident that they're bad, because they either explode, or smell *really* bad.

[menace]

When the flyback goes on the k7000's they blow fuses without the HOT being shorted.  ken taught me a neat trick--replace the fuse--pull the flyback and power on--very briefly--if it doesn't blow the fuse then the flyback is toast.

[Ken Layton]

A flyback is a high voltage transformer. It is usually mounted in one corner of the main circuit board and is the largest component on the board. Most flybacks are black in color, but I have seen some colored white or gray. It will have one thick red (or sometimes black) wire coming out of it leading to the rubber suction cup on the picture tube. This guy generates the 19,000 to 24,000 volts necessary to drive the picture tube and IT CAN KILL YOU!

Flybacks can fail at any time for any reason, but they will generally either crack and arc high voltage to some nearby piece of metal or they will violently explode like an M-80 firecracker.

[ChadTower]

Well, it's safe to say now that the flyback on the WG I'm repairing isn't dead!  It doesn't smell bad, it's not cracked, there's no arcing.  It does still need a reflow, though.

[Ken Layton]

An original Wells k7000 flyback likes to crack all along the focus and screen controls so look very closely for tiny cracks. The replacements are holding up quite well, though.

[ChadTower]

So it would likely be a good thing to buy a replacement anyway, since it will inevitably fail at some point.  Especially since you just found a great source.  Yes?

[Ken Layton]

It never hurts to have a spare. You see if you have a brand new spare then the that's in it now will never fail.