CRT color TV loose its actual Color

[mamun2a]

14" Hitachi, 1999. This TV set now colorize by Magenta color. every color is colorized by magenta so original color is not displayed also brightness is less then previous now.

what caused the problem, is it repairable at home?

help me

mamun2a
dhaka, BD

 

[unclejed613]

green gun dead, or dried out electrolytics in green amplifier. dried out electrolytics are more common, but CRT's aren't made to last either. the small circuit board on the back of the CRT is where you'll find the electrolytics. common values are 1uf/50V, 10uf/50V. there may be others there with voltage ratings as high as 450V, depending on the model of TV. if you don't have a way of measuring capacitor ESR, assume all of them are bad (or will be soon). carefully inspect the board, and write down the value and voltage of every capacitor on the CRT board, and if there's printing on the board, where each cap goes (C101, C201, etc...) replace them one at a time, don't try to strip all of them off the board at once and repopulate the board, it WILL get confusing that way. pay attention to where the minus strip on each one is, because if you put one in backwards, it WILL explode when you apply power to it.

also check the solder connections on the CRT socket. the heating and cooling a tube goes through can break the solder connections on the socket, and those connections will need to be resoldered. check the solder connections of all of the transistors on the board as well, as they also have a tendency to break.

if after this work is done, you still have no green, it is possible the picture tube is bad. picture tubes are more expensive than a new TV, and only an experienced technician should replace one, as there are safety hazards and alignment procedures involved that just plain are not taught anymore since the flat panel has taken over the market...

 

[mamun2a]

thank you very much, Unclejed.

i will check, but how to avoid high voltage of flyback transformer ?

 

[yusim]

safety precautions!

i will check, but how to avoid high voltage of flyback transformer ?

CRT displays can store thousands of volts even when it not plugged in!

Make sure to discharge all capacitors within reach
before you do that do not touch the board with 2 hands so as not to complete a circuit with your heart!

do not open your CRT until you are familiar with all the safety precautions

here is a good link to check out: https://www.repairfaq.org/sam/safety.htm

 

[mamun2a]

thank u dear.