Toshiba 42HL67 LCD no power at all "hit by lightning"

[sigmanuh1457]

I am working on Toshiba 42" LCD. The the was hit by lightning. I tested the main fuse right as the 120v comes into the tv and it is good and is passing voltage.

I also checked all the diodes on the power supply and they all seem good. I tested a few resistors on power supply as well and they seem good.

So, what should I look for or check next? I was reading some other post about sets that get by lighting and few mention testing 5v line and standby 5v....if this is the case, can someone explain how to do this?!?! Thanks

I have no led light coming on the front at all.

[awyatt2]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

there are voltages usually printed by the connectors. the main wire will be a two pin plug bringing in power, the smaller plugins with numerous wires should be labeled. you set meter to dcvolts, put red on that pin you are trying to read voltage on and the black pin to ground. look around on the power supply you will se 3.3v 5v 12v 24v you should be very close to these set meter to 20v scale for all but 24 you then need to go higher than 24 to check it. be carefull around the heatsinks most all are live and will give you a shocking suprise

[budm]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

I am not sure how well you know about testing the voltages on the primary side of the power supply, if you do know enough, then check and see if you do have 120Vac at the two inner pins of the bridge rectifier mounted on the small heat sink.
You should remove the pictures and use the attachment to up load the pictures instead, a lot of people may not want to reply or look at the=is post due to the way the pictures are being displayed.

[awyatt2]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

1 st determine if you have voltage, if one is missing or all are missing it only takes one not to work and the tv may be totally dead, if all are missing then you would have to find why. bottom line is no power no picture. you may have only took out a surge protection device. and then lightning is un predictible as to where it would have stopped but usually you find burned components and burned boards.

[awyatt2]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

hi bud glad to see you, how is the other side of the us

[budm]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

Enjoying 3 days off in sunny Cal bay area, we are lucky here for not having lighting and bad power here in Cal. How about you?

[awyatt2]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

well weather wise ok, health wise, about dead with the flu. not getting to enjoy any time off because of it.
on the tv does it appear to you as it does to me he has a main and sub ps? i have one toshiba that has .may be lucky and only have a bad spd.

[awyatt2]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

just looked on shop jimmy and blew up a pic of his ps, there are several pico fuses on it know i saw at least 5 maybe more. it has more than just the one mains fuse.

[sigmanuh1457]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

Okay, I have tested all the dc volts and i get nothing on all of them.

The ribbon has the following voltages labeled...

5v1
40v
18v

12v
5v
24v_INV

[awyatt2]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

you have several pico fuses look like a resistor with one single stripe

[budm]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

awyatt2, the TV does have main and sub power supply boards, so he should look to see if he as AC at the main rectifier bridge, and also see if he as any DC on those two large electrolytic caps and check all the fuses. The pictures do not look very clear, they have really high contrast looking pictures so it is really hard to see what are on the boards.

[awyatt2]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

check f882,f884,f885,f870. then check the bridge and see if it is open they always dont go shorted. post back what you find.

[budm]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

Are there two bridges on the main power supply, one in on the heat sink (bottom of the picture), one is not on the heat sink (about top left of the picture).

[awyatt2]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

bud i got these numbers from a ps on shop jimmy for the same model. hopefully it would be in there or maybe the bridge went open instead of shorted. been quite a while since i saw an open bridge i think it was an old astron 12 analog ps. blooming thing still worked at about 8v max out. but then it had two full wave rectifiers back to back.

[awyatt2]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

good call bud, yes, i looked on shop jimmy one is non heatsinked and one is on a smaller heatsink

[RJARRRPCGP]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

Enjoying 3 days off in sunny Cal bay area, we are lucky here for not having lighting and bad power here in Cal. How about you?

Same here. Been sunny for 3 days so far in south central Vermont.

[selldoor]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

Your Pictures are no use for troubleshooting they should look like this
We can help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Examples of what is needed
https://www.badcaps.net/forum/attach...1&d=1290283049

https://www.badcaps.net/forum/attach...7&d=1280167246

[sigmanuh1457]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

The fuses test fine. (f882,f884,f885,f870)

How do I test the bridges and do you have board location number for these as well?

[sigmanuh1457]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

Here is the best I could do giving better shots of the power supply board. I had to break it up in upper and lower pictures.

[sigmanuh1457]

Re: Toshiba 42HL67 LCD no power at all "hit by lightning"

Back of the board...