Rewinding Your Own B+ Coil

If you have been in the CRT Monitor repair i’m sure you would have come across shorted B+ coil problem. It could come in the radial type or sometimes the b+ coil could look like a small transformer. The best tester to test B+ coil is the dick smith flyback tester or the Blue Ring Tester. Once you have confirmed that the B+ coil winding shorted you can choose to replace with a new B+ coil, salvage from junk board that have similar inductance or even rewind back the coil by yourself.

If you have decided to rewind the coil then you have to remove the winding from the ferrite core and count the lenght and the diameter. Go to the electronic shop and get the same spec. Sometimes you can buy the wire from a rewinding shop too. Loop back the wire and test again for the inductance and test also with coil tester to see if there is any short between windings or not. The inductance value lower 20% compare to the original value can still be use. Once everything tested okay, you then can proceed to fix back to the Monitor. Just before you power “On” the Monitor make sure the corresponding components like the B+ FET, current sense resistor, HOT and even flyback primary winding are good otherwise the Monitor may still wouldn’t work and in some cases it may burn the newly rewinding B+ coil again. Happy rewinding