dear friends please help me!
i have a chinese TV(Unbranded). most of the components installed are from Sanyo.
there is a problem. The CMOS IC is LC863328B by sanyo.
in my TV the blue color is missing or very low and red and green at the highest which gives the yellow background. there is no option for setting RGB in my remote or panel.
what to do.
thanks
My friend, your trying to find an adjustment that is not going to help you. There most likely is an adjustment for the R.G.B. Alighnment in the service menu, but you have a drive problem. You will need to know how to use a multimeter. Compare the rgb inputs directly from the main video jungle IC. Make sure they are all about the same. If they are not then most probable, you have a drive problem. if they are check all the bias and voltages on the differant drive transistors. you should be able to tell what one in good or bad. if they all read around the same voltages, Guess what? You have a bad picture tube. not alot to do with this except replace it. Good luck and let us all know how you made out.
thanks for the reply!
i wish to ask can that be adjusted with any remote control?
ok!
the jungle IC is LA76810 and i have the data sheet for that. i am an electrical engineer and i know well how to use the multimeter.
should i check the volts on IC pins with respect to its GND pin?
Yes you can measure from the COLD ground. Then start with the driver crt board.
thanks well! i shall do that.
what if the required volts at the RBG corresponding pin are different than in data sheet. whats the allowable+/- variation.
if the volts are out of range what to check next?
thanks again for the help.
You only need to check the RGB output voltages. If any are low, pull off the crt socket off the picture tube and see if it comes back up. If it does not, check surrounding componets on the low pin and if all those are good change the chip. You really do bot have to check the voltages on the chip though. Simply check the base and collector voltages on each drive transistor on the CRT socket. If you have low voltage there, check around for open resistors orr resistors that have changed value.
thanks larry
about CRT socket you mean the socket that is connected to the neck of the CRT?
THE drive transistors are in that socket? not on main board?
i mean if by removing the socket i get voltages at IC pin out(RGB) correct then the fault lies in the socket?
if by removing the socket the voltages remain same(low/high abnormal). i should go for changing the IC or should i trace the pin's path and check the components on that path.
i hope you will be kind enough to clarify what you meant in your post
regards
The drive transistors are usually mounted on the CRT board where the socket is, not in the socket. In some case or on older sets the three drive transistors are mounted on the board. Depending on how old this set is, there could also be an inl-ine package mounted on the CRT board and this would be the drive hi-brid IC. I am not there with the set. you tell me where the parts are located. If you cannot find the said parts or do not know what they are, or what they look like, my friend you should not be experimenting inside this TV set. Take this repair to a trained service tech.
thanks larry!
i love to do the rectification by myself. this is my hobby!
well i finally rectified the problem!
There was a 4-5 wire connector in the CRT board. one of the wire in the connector was broken, when i repaired that wire, blue color came and my TV is now perfect.
in my CRT Board there is no ic just 3-4 transistor, caps and few resistors!
any way i did that!
could you please tell me where that connector lines come from and whats its name!
thanks any way.
take care and have a nice day
Ok, now your on track. The connector supplys the RGB drive voltage from the main board. Glad to hear you sorted it out.