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

[tom66]

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

Can you take some close ups of all the labels next to the connectors which go to the main board (the one with the video inputs on it.)

[selldoor]

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

Much better pics - thankyou- I dont know about 2 bridges but you can start on one I think I see which is the thin black rectangle to the left of the two green transformers.If it has a +~~- on thats what it is.

To Test: Take a multi-Meter and switch it to Ohm x 1
Test between one of the "~" and "+" legs.
You should get either an almost-zero reading in one direction, and when you reverse the test probes, you should get an almost infinite ("sleeping 8") reading.
Now try the same between this "~" leg and "-".
Same as above.
Now repeat the same tests with the other "~" leg, and "+", and then "-".
Same as above.
If you either get almost zero or almost infinite in BOTH directions, then the rectifier is fried.

An interesting item ive not seen before is the DG1U
some sort of power relay just above the left hand green transformer at SR80. Will have to try and find out what it is - it may be ok but it looks a bit overheated on the underside.

[awyatt2]

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

here are the two bridge rect. circled in red

[awyatt2]

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

another thing have you tested the diodes in the triangles three legs heatsink mounted? then near tp1 is that a jumper wire i see or just some type of shadow. the diodes i am asking about will shut the ps down i am watching a 55 inch samsung i bought for 50 and that was all that was wrong with it. two blown diodes. i rigged my own because i did not want to pay 14.95 each for the replacments. i dont remember which diodes i used but they were 1.18 a pair. i can find out though i have a few spares i bought just in case the first ones failed. that was approx 6 weeks ago and not even one blip. the diodes are usually marked on the case as to the connection common anode common cathode. any way the way i moded them was tied the cathode ends together and ran a jumper to the center and the anode legs went in the outer holes. mine were common cathode.the one beside it was common anode and it was ok. but you could do the same here as long as type, amps, and voltage are good. i used kapton tape to insulate the solder and leads along with heatshrink and a small copper strip tied to the heatsink to help cool. just a suggestion in case you need it.

[sigmanuh1457]

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

OKAY, the TP1 is just blank prong... and there is mark from factory there with marker.

I tested the 3 prong diodes and they are testing continuity.... which I believe make them shorted. Can you please explain how to properly test to make sure I am testing them correctly.

[sigmanuh1457]

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

And when I test those bridges one seems to be testing correctly, the other one I am kinda iffy on it...

My fluke meter should shows "OL" in one directions....

[awyatt2]

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

you may have to remove them to test properly. the cathode black lead and red on anode should read if you have a diode test on meter. reverse probes and you should get ol or whatever you fluke shows like the meter probes are open. cathode end will be the one with the straight line with arrow pointing toward it. google testing bridge rectifier and watch on utube, you can follow along with him.

[awyatt2]

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

here is a link you can watch, he shows you how to test a bridge just like you have. both test same way. if you follow him you wont make a mistake.remember the tapered corner is + and flat outer end is _ the two center legs are ac in.
on the three legged diodes usually on the front of the case you will see two diode symbols.cathode end will always be the flat line with the arrow pointing into it

[sigmanuh1457]

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

here is a link you can watch, he shows you how to test a bridge just like you have. both test same way. if you follow him you wont make a mistake.remember the tapered corner is + and flat outer end is _ the two center legs are ac in.
on the three legged diodes usually on the front of the case you will see two diode symbols.cathode end will always be the flat line with the arrow pointing into it

no link?

[awyatt2]

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

http://www.youtube.com/watch?v=dqkT6hF0O3E
if it dosent go this time you will have to google it.

[sigmanuh1457]

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

Okay, sorry for delay trying to test these...

But my soldier iron just not seem up to the task to desoldier the bridges. They are testing weird in circuit.

So, I guess im gonna have get different iron or something.

[awyatt2]

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

i can check the ps if you want to get it to me around 150 miles from atlanta. you need a good quality solder station to work on these. the non lead solder does not help either.

[efan]

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

Just borrow this thread, the fuse F880 on this power supply is blew, It marks 125V 5A. I wonder it is a fast blow or a slow blow fuse? So far, I replaced it with a 4A fast blow fuse and the TV works. However, it may blow if there is power surge.

[vinceroger69]

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

i would of thought fast/quick blow so realy needs replacing with a 5amp one
edit as tom66 says i was going of you wrote 125v 5a not what would be on the board marking.

[tom66]

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

Usually it's type "T" for time delay.