Toshiba 37CV510U bad inverter

[ntehicks]

when I first opened the tv up and looked at the inverter I could tell it had failed. I purchased a brand new inverter and installed and now the tv works for about 1 hour and then the back light goes out. but I still have audio. what would I test first.

[ntehicks]

Re: Toshiba 37CV510U bad inverter

here are some pictures

[ntehicks]

Re: Toshiba 37CV510U bad inverter

here are some more pictures

[ntehicks]

Re: Toshiba 37CV510U bad inverter

and more pictures.

[budm]

Re: Toshiba 37CV510U bad inverter

https://www.badcaps.net/forum/attach...6&d=1428428242
It looks like the cap by the white fuse has bottom rubber seal bulging out?
https://www.badcaps.net/forum/showth...901#post547901
Also liquid came off it.
So are those pictures of the old boards or new boards?

[ntehicks]

Re: Toshiba 37CV510U bad inverter

these are pictures of the old one.

[budm]

Re: Toshiba 37CV510U bad inverter

So are you still getting the 24VDC for power and the BL-ON command for turning on the inverter?

[ntehicks]

Re: Toshiba 37CV510U bad inverter

if I let the tv sit for about 10 minutes then turn it back on the tv will work for about 1 hour. I will test the BL-ON and the 24 volts. is it possible that the power supply was damaged when the first inverter went out?

[budm]

Re: Toshiba 37CV510U bad inverter

You need to find out what is missing first when the backlights go out, if the 24VDC disappears or the BL-ON disappears.

[ntehicks]

Re: Toshiba 37CV510U bad inverter

what voltage should be on the BL-ON

[budm]

Re: Toshiba 37CV510U bad inverter

>2.5VDC (can be as low as 1.75V) = ON, <1VDC = OFF.

[ntehicks]

Re: Toshiba 37CV510U bad inverter

and that should be solid and not fluctuating ?

[budm]

Re: Toshiba 37CV510U bad inverter

It can varies little bit as long as it is above the trigger level. What do you get right now when it is working and not working?

[ntehicks]

Re: Toshiba 37CV510U bad inverter

ok here are some pictures of the connectors on the power supply

[ntehicks]

Re: Toshiba 37CV510U bad inverter

in picture 20150407-201954 this heatsink gets extremely hot. all of the rest of the heatsinks on the power supply are just warm. this one I think is the one that is driving the 24volts to the inverter is very hot. I have tested the 24 volts and when the backlight is on and when it turns off I still have the 24volts. where do I test the BL-ON?

[budm]

Re: Toshiba 37CV510U bad inverter

OK:
https://www.badcaps.net/forum/attach...6&d=1428428242
PIN 12 ON/OFF is the BL-ON PIN.

[budm]

Re: Toshiba 37CV510U bad inverter

That heatsink is for the rectifier diodes so may be something is drawing too much current, or problem with the rectifiers which you should check.

[ntehicks]

Re: Toshiba 37CV510U bad inverter

ok this connector with backlight in fault and not on
pin 1 gnd = 0
pin 2 5v1 = 4.9
pin 3 gnd = 0
pin 4 12v = 11.7
pin 5 12v = 11.7
pin 6 12v = 11.7
pin 7 gnd = 0
pin 8 power tv = 3.2
pin 9 power dv = 4.9
pin 10 gnd = 0
pin 11 24v = 23.8
pin 12 power sig = 2.7
pin 13 18v-a = 17.9
pin 14 gnd = 0

ok and this is when I restart the tv and the backlight is on
pin 1 gnd = 0
pin 2 5v1 = 4.9
pin 3 gnd = 0
pin 4 12v = 12
pin 5 12v = 12
pin 6 12v = 12
pin 7 gnd = 0
pin 8 power tv = 3.2
pin 9 power dv = 4.9
pin 10 gnd = 0
pin 11 24v = 23.8
pin 12 power sig = 2.7
pin 13 18v-a = 18.2
pin 14 gnd = 0

[budm]

Re: Toshiba 37CV510U bad inverter

Why don't you check the signal right at the inverter as I indicated in post 16?

[ntehicks]

Re: Toshiba 37CV510U bad inverter

ok I am testing pin 12 BL-ON and I get 3.2v when the inverter is on and the same when the inverter goes off.