Mongo
Well-known member
So a buddy and I were working on a couple of modern WeiYa style replacement chassis last night. Both had vertical collapse. In these cases I usually stampede directly to the transistors in the circuit, pull, test, and replace. On these monitors, that didn't get me the quick results I was looking for.
After some time probing around with a scope, the problem was found near the flyback on both monitors. Both of these semi-modern monitors have 1/2 watt 2.2 Ohm resistors in several of the traces coming off the flyback which then feed diodes which feed the rest of the circuit. It would appear the purpose of these resistors is to act as a fuse to protect the flyback in the event of a short in the circuit. One chassis had a visibly burnt resistor. The other had a resistor that looked fine physically.
So... if you still have collapse after checking the "usual" suspects, keep these little "fuses" in mind and remember that the can be very open without showing any outward damage..
After some time probing around with a scope, the problem was found near the flyback on both monitors. Both of these semi-modern monitors have 1/2 watt 2.2 Ohm resistors in several of the traces coming off the flyback which then feed diodes which feed the rest of the circuit. It would appear the purpose of these resistors is to act as a fuse to protect the flyback in the event of a short in the circuit. One chassis had a visibly burnt resistor. The other had a resistor that looked fine physically.
So... if you still have collapse after checking the "usual" suspects, keep these little "fuses" in mind and remember that the can be very open without showing any outward damage..