Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

How to repair green "fog" on a display in a Sony TV?

Status
Not open for further replies.

Tracid

Member level 3
Joined
Nov 1, 2006
Messages
57
Helped
3
Reputation
6
Reaction score
3
Trophy points
1,288
Location
Neded, Slovakia
Activity points
1,756
Hi!
I would have a questions to you!
I am familiar with electronics but when answering please take into account that i never worked with TVs before!
So my question is about TV failure.
My TV is a Sony Trinitron,its about 14years old.Once it has the problem that the vertical image got contracted(thin horizontal line at the center of screen).
The problem was a faulty Capacitor(the TV repairer repaired it).Now the whole PCB including the one on the neck of the CRT tube is soldered again so now there are new joints at the components.
now when powered ON the image is not clear,but it seems like the Green colour makes ´fog´ on the whole screen.It happens all time during operation.

Could you please recommend me how to troubleshoot this problem?
I read the Sams TV repair FAQs,and found something similar but since i am not familiar with TVs i dont know where to start.

Thanks!
 

Re: foggy TV

Sounds like the green cathode driver transistor went short or leaky. If you post the model number someone may be able to help. Make sure that soldering the connections on the tube pcb did not cause this short as the color driver transistors often are located on this pcb.
 

foggy TV

Its type is : Sony Trinitron KV-2184MTK
I always take attention on shorting.

I have the schematic diagram of it,i can attach it if it helps you to find the problem!

Thanks!
 

Re: foggy TV

Can't hurt to post the diagram
 

foggy TV

My brother said me he unfortunately left the cam-to-pc cable at his workplace so i cant attach it now.You have to wait for it...

Added after 1 hours 50 minutes:

Now i disconnected the Green from the trace which goes to the CRT tube(at
the collector of Transistor) and now it disappeared. but when viewing the
screen its now very reddy.
I am going to try to swap colours.
 

Re: foggy TV

hi
if u can give the chassis number it'll be easier to find the right schematic diagram and getting effective help , so write down ur tv's chassis number here .
Kind Regards
 

foggy TV

I dont know what do you exactly mean under chassis but i alredy wrote down the type code!
 

Re: foggy TV

Test the green drive transistor as I bet it is faulty. Compare with the red or blue if you are in doubt.
 

foggy TV

Thanks for the replies but the problem is alredy solved!
There was a fault around the IC on the big mainboard just from where the cables go to the small PCB on the neck of CRT. I desoldered the whole IC and made new joints. The problem absolutely went away!
 

foggy TV

want to know substitute of this transistor RD-JT91 for LG projector
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top