ELONEX JC378BB13E Screen Flashes

[anotherdude]

Tv turns on with a white flash on the screen then darkness

Had a few bulging 35v caps which have now been replaced but made no difference

likely a shorted panel or bad inverter?

[cheapie]

Re: ELONEX JC378BB13E Screen Flashes

By "darkness", do you mean no backlight, or no picture? Shine a flashlight at the panel and see if you can make out a picture.

[anotherdude]

Re: ELONEX JC378BB13E Screen Flashes

By "darkness", do you mean no backlight, or no picture? Shine a flashlight at the panel and see if you can make out a picture.

it's sealed off at the moment will have to strip it down first

[cheapie]

Re: ELONEX JC378BB13E Screen Flashes

it's sealed off at the moment will have to strip it down first

Huh? I meant just turn it on (fully assembled), wait for it to go dark, and shine a flashlight on the screen up close to see if it's showing anything at all.

[anotherdude]

Re: ELONEX JC378BB13E Screen Flashes

Huh? I meant just turn it on (fully assembled), wait for it to go dark, and shine a flashlight on the screen up close to see if it's showing anything at all.

sorry yes i've tried that previously on a another backlight problem'd tv and could never see the image from the front only from the back when shining a torch

it is the backlight that flshes very briefly as soon as the tv is turned on

[budm]

Re: ELONEX JC378BB13E Screen Flashes

Any good pictures of the inverter board, power supply board?

[tom66]

Re: ELONEX JC378BB13E Screen Flashes

Do you get a brief blue LED light on the inverter board?

[anotherdude]

Re: ELONEX JC378BB13E Screen Flashes

great, removing the frames from around the tv to access the inverter, got access to it, must of forgot to screw one of the screws back into the frame for the power supply and caused a short when i plugged it back in

next thing i know the powers tripped and now have no standby light

[anotherdude]

Re: ELONEX JC378BB13E Screen Flashes

heres a shot of the power board anyway

and what maybe the cause of my no standby now?

[tom66]

Re: ELONEX JC378BB13E Screen Flashes

You've probably popped the fuse.

[anotherdude]

Re: ELONEX JC378BB13E Screen Flashes

You've probably popped the fuse.

thats what I thought but i'm getting 124v on the heatsinks near the large cap

[tom66]

Re: ELONEX JC378BB13E Screen Flashes

That means very little because the heatsinks are connected to a pair of class Y caps which are sometimes before the fuse.
You should try checking the fuse directly...

[anotherdude]

Re: ELONEX JC378BB13E Screen Flashes

That means very little because the heatsinks are connected to a pair of class Y caps which are sometimes before the fuse.
You should try checking the fuse directly...

fuse tests good, also seeing voltage on the tops of the smaller caps

little to no voltage secondary side

the first picture i uploaded is it supposed to look like that? there are others with the spacer on but none have that green wierd colour on them

[tom66]

Re: ELONEX JC378BB13E Screen Flashes

Any standby voltage? Try without main board. Check voltage across 450V cap. Check voltage across C31,C32,C33,C34, and one small cap near the big 450V cap.

[anotherdude]

Re: ELONEX JC378BB13E Screen Flashes

Any standby voltage? Try without main board. Check voltage across 450V cap. Check voltage across C31,C32,C33,C34, and one small cap near the big 450V cap.

no standby voltage, nothing on any of the pins leading to the main board

big cap = 124v
c31 = 117v
c32 = 122v and dropping
c33 = 122v and dropping
c34 = 119v and dropping

cap near large cap 122v

[tom66]

Re: ELONEX JC378BB13E Screen Flashes

124V is that ACROSS the cap i.e. red on positive, black on negative. Same for other caps.

[anotherdude]

Re: ELONEX JC378BB13E Screen Flashes

124V is that ACROSS the cap i.e. red on positive, black on negative. Same for other caps.

no sorry tom was meausring across the top

can't reallly measure the other caps as there on the underside but will try later

but the big cap measures 327v

[anotherdude]

Re: ELONEX JC378BB13E Screen Flashes

anyone able to advise on where to go from here, can't seem to spot the problem or bad partt