Digitrex CTF4071A - Screen/Backlight problem.

[davey4eva]

Hi guys,
Newbie here trying self teach the ways of the T.V engineer.

I dont know if this is in the right place to put this thread so i apologize if it is wrong.

As you can see from the photos i have attached. The tv comes on fine, but there is only part of the screen visible (the blue bits) and the rest is dark, i can see the channel name (HDMI 1) drifting around the screen so i know its showing but i can work out whats wrong.

Any ideas?

Thnaks

[Alastair E]

Re: Digitrex CTF4071A - Screen/Backlight problem.

Possible T-Con fault but also the panel itself suspect.....

Pictures of the set internally could help....

[davey4eva]

Re: Digitrex CTF4071A - Screen/Backlight problem.

Possible T-Con fault but also the panel itself suspect.....

Pictures of the set internally could help....

Here are the t.v's organs. Thanks

[tom66]

Re: Digitrex CTF4071A - Screen/Backlight problem.

Check in a dark room if the whole panel lights up (backlight)
I'd say bad panel myself, but hard to be sure.

[davey4eva]

Re: Digitrex CTF4071A - Screen/Backlight problem.

Check in a dark room if the whole panel lights up (backlight)
I'd say bad panel myself, but hard to be sure.

Left side does not light up. But shining a torch on the screen shows that the screen is working as i can see the channel number floating around.

[Alastair E]

Re: Digitrex CTF4071A - Screen/Backlight problem.

Backlight problem then.

Check that you have a 24V supply to the backlight board when the set is running.....

[davey4eva]

Re: Digitrex CTF4071A - Screen/Backlight problem.

Backlight problem then.

Check that you have a 24V supply to the backlight board when the set is running.....

Can you remind me of where to check for the 24v? sorry, but i think i have early onset of dementia lol. (no joke)

[Alastair E]

Re: Digitrex CTF4071A - Screen/Backlight problem.

there should be some marking on the plugs sockets of either the PSU or the Backlight boards. You'll find there are several wires in parallel, one set is the ground, the other set the 24V There'll be one or two more, for BL-On and in some cases BL-Cont. or BL-Dim

Its the parallel wires we are looking at, Voltage between those and chassis. Just check along the plug with meter--you'll find 'em....

[davey4eva]

Re: Digitrex CTF4071A - Screen/Backlight problem.

Thanks. Will take a look

[davey4eva]

Re: Digitrex CTF4071A - Screen/Backlight problem.

Ok. So i checked the 24v and it reads fine, although the 24v/gnd goes to the t-con board? also found out there is no sound, connected the PS3 to the tv to show exactly how much screen was missing, i have attached pics.

So like i said, no sound. Dont know if thats the speakers or the board. but regarding the screen/picture/backlight, could it be the Inverter?

Would really like to get this tv up and running.

Thanks guys.

[davey4eva]

Re: Digitrex CTF4071A - Screen/Backlight problem.

there should be some marking on the plugs sockets of either the PSU or the Backlight boards. You'll find there are several wires in parallel, one set is the ground, the other set the 24V There'll be one or two more, for BL-On and in some cases BL-Cont. or BL-Dim

Its the parallel wires we are looking at, Voltage between those and chassis. Just check along the plug with meter--you'll find 'em....

Also, it has no reference to BL-On - BL-Cont or BL-Dim anywhere :/
im thinking this may be an awkward set