My cousin came to my shop this morning and brought me a CRT TV set. There was no sign of a working TV, not even a stand by LED. My cousin manages a Hotel in the city of Bethlehem and he has over 100 rooms that has the same kind of TV set. This morning, he said that he had problems with electricity and some of the TV sets in the room just stopped working.
When I opened this TV set, there was no sign of smoke. The fuse was not even blown. I had to blow the dust with a dust blower so I can see the component on the board. I started checking voltages reaching the main capacitor, there was no reading on the main capacitor indicating a problem in the primary power supply.
I used a magnifying lens and a bright light so I can see any kind of burn or blown parts. I saw just one disk capacitor (681 2kv). It was not blown, but I could see cracks on the side of it. There were two of them in parallel. The other disk capacitor was not blown. I think this was caused by a high voltage reaching the primary power supply and these capacitors protected the TV from this high power.
I replaced this blown part and I was about to turn the TV on but I did not. I wanted to make sure that there were no more blown or shorted parts in the set. I attached a light bulb on the fuse holders and turned the TV on. The light was bright then it went dim assuring me that all is well and it is ok to turn the TV on. I put the fuse back on and turned the TV on and it worked nicely. I checked all the voltages in the power supply and all were within specifications.
As always, I tested the TV set for two hours to make sure all is well. My cousin was happy to see his TV comes to life. He will bring me more of these TV sets to repair in my shop. I am just hoping that these TV sets will have the same fault as this one that I just repaired.