Toshiba 40E200U1 turn ON but no backlight, no video

[alfredomfr1]

Power led turn green, but there is not backlight and can't see video in the dark with a flashlight.

BL-ON: 5v
Dim, ACD: 0v
Power ON: 3.6v
5v: 5v
12v and 24v: 0v

I jumped 5v and Power ON nothing, 5v, Power ON and BL ON nothing, Power ON, ACD, BL ON and 5v nothing

I changed the MB 2 times, with the original the label toshiba in the plastic bezel light up white but not image or backlight, with the second one, not turning on (i assumed is defective) and with the third one turn on, the label toshiba remain off but no video, no backlight.

[dick_barton]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

ACD which I believe is AC detect = 0V so there's problably a fault with the power supply and that is why you don't have 12V and 24V. I suspect that the main board is fine.
Can you locate a manual for the power supply or provide high quaity pictures of the front and back of it .

Edit
Check R101, R102, R103, R104 & R105

[CapLeaker]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

Jump pson with a 1k resistor to STBY voltage. Do the same with the BLon. Check how much DC V you get on the main filter capacitor. Be careful. Check if the rectifier diodes on the 12V/24V on the secondary are shorted.

[alfredomfr1]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

I have 167v in each main capacitor

[CapLeaker]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

check for VCC on U101. What is printed on U101?

[ReeceyBurger123]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

Ahh SSI_400_14A01 inverter-I meant shit. Remove/unplug the inverter and see if the set powers up.

[alfredomfr1]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

CapLeaker: U1 (can't found U101) is a L6571B see picture
Pin 1: -5.5v
ReeseyBurger123: With the inverter disconected same no 12v, no 24v

[budm]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

CapLeaker: U1 (can't found U101) is a L6571B see picture
Pin 1: -5.5v
ReeseyBurger123: With the inverter disconected same no 12v, no 24v

What did you use for meter GND to get that - 5.5VDC on the Vs PIN 1?
Is it really Minus 5.5VDC? can't be right.

[alfredomfr1]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

I did the measure again is something around -9.50v to -10v. Using GND on the board connector and in tv chasis same measure.
I did the measure right before send this message and is -4.25v. Crazy !!
Note:
Multimeter is ok

[Diah]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

from yours Photo https://www.badcaps.net/forum/attach...6&d=1472422224

the Audio Dig Red LED turn On, check your remote control , did the set response for it if not then you have firmware issue eeprom etc,

[alfredomfr1]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

The TV turn ON, is just 12v and 24v are not present, with the inverter connector pluged or not same thing. Im thinking is a power board problem and I need some help to repair the power board

[Diah]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

you mean when you plug it at wall socket it turn on direct correct ? can you put it in stand by state ? if no then issue as i write before

[alfredomfr1]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

Yes I can turn ON and OFF

[Diah]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

good in this case you should have picture on screen by dark room and touch light. also what recovery write if you plug out the inverter while set on and back u should have backlight for awhile

[alfredomfr1]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

I didn't see nothing on the screen with a flashlight and will do the plug out test tomorrow but as i write before there is not 12v or 24v

[Diah]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

if you have not 12 24 v yours tv will never boot and turn on or off.

[budm]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

I did the measure again is something around -9.50v to -10v. Using GND on the board connector and in tv chasis same measure.
I did the measure right before send this message and is -4.25v. Crazy !!
Note:
Multimeter is ok

You used the wrong GND, when you make measurement in the HOT side, you need to use the negative leg of the main filter cap as the GND ref for your meter.
BTW, is there wire on the ACD pin? This TOSHIBA good ACD signal LOW = Good, right now you have 0VDC so it is OK.
You do have PS-ON signal to turn on the 12V/24V Switched power supply section.

[alfredomfr1]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

budm: Using negative leg of the main filter pin 1: -165v
Diah: TV turn on and off perfectly.

[budm]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

MINUS 165VDC? It cannot be MINUS reading.
165V is way too high, the clamping Voltage on that pin 1 Vs pin is around 15V.
Are you sure you are measuring at the correct pin, and measure it correctly?

[alfredomfr1]

Re: Toshiba 40E200U1 turn ON but no backlight, no video

I'm agree with you but that's the reading from pin1, thru pin5 = -165v dc