Samsung UN55D6450UF - Lightning Damaged

[ndoggfromhell]

A co-worker decided to dump this on my lap and I'd like to help him out since he has done me a few favors. Tv was working great, house was struck by lightning and it died. No power, nothing! He read online that there are three boards in the TV and that replacing all three would fix it. He brought me a tv and a box of boards... I figured I'd swap all three of the bad ones for the good ones and see if it works. (Hey... sometimes it can be that simple right?) Now I get power, the TV panel turns on but won't turn off with the power button. Also, I get no image on the screen. I replaced the power board, the input board, and the T-con board. What else could be the culprit? All three replacement boards are the exact same part number as the factory boards. All purchased online from reputable sales people. Thoughts?

[tom66]

Re: Samsung UN55D6450UF - Lightning Damaged

Swap the old T-con over and see if it runs. If not you probably got some dud boards. About ~20% of eBay boards seem to be dead on arrival due to lack of testing or improper handling by the seller.

[ndoggfromhell]

Re: Samsung UN55D6450UF - Lightning Damaged

Swapped T-Com board and it makes no difference. Could the power switch panel be bad?

[tom66]

Re: Samsung UN55D6450UF - Lightning Damaged

The screen is visibly glowing or not?

[ndoggfromhell]

Re: Samsung UN55D6450UF - Lightning Damaged

Yes, visibly glowing. The weird thing is when I turn the power off, it turns back on almost immediately. Doesn't stay powered off.

Also, In the corner of the tv there is an LED to show remote function. It illuminates when I press remote buttons so I know the TV is at least seeing transmissions from the remote.

[tom66]

Re: Samsung UN55D6450UF - Lightning Damaged

Do you have a digital multimeter?

[ndoggfromhell]

Re: Samsung UN55D6450UF - Lightning Damaged

I do, but it's an inexpensive one.

[tom66]

Re: Samsung UN55D6450UF - Lightning Damaged

I've used inexpensive ones before... Show us a picture. It can't be that bad...

[ndoggfromhell]

Re: Samsung UN55D6450UF - Lightning Damaged

There you go!

[tom66]

Re: Samsung UN55D6450UF - Lightning Damaged

Nothing wrong with that.

For the tests put the RED probe in the "V" jack. Leave the BLACK probe in the COM jack.

We will need pictures of the chassis and of each board to show you where to make tests.

[ndoggfromhell]

Re: Samsung UN55D6450UF - Lightning Damaged

This is the whole backside of the TV



This is the input board (cell phone is my only camera here)



This is the T-com board.



And the power board

[tom66]

Re: Samsung UN55D6450UF - Lightning Damaged

OK, I've highlighted the fuse on the T-con.

Set your meter on the DC voltage range, 20V (V=). Put your red probe on one end of the fuse, black probe on the chassis of the TV. Turn the TV on. Then, move the probe to the other end of the fuse. Record and post the reading you get on both ends.

(The TV should be switched on and the screen should be glowing.)

[ndoggfromhell]

Re: Samsung UN55D6450UF - Lightning Damaged

forgive me, but i don't see where you highlighted it

[tom66]

Re: Samsung UN55D6450UF - Lightning Damaged

LOL, sorry! Let's try that again...

[ndoggfromhell]

Re: Samsung UN55D6450UF - Lightning Damaged

the meter fluctuates for a second, but reads all zeroes. I'm using the tv mount as the ground (the metal part of course)

[tom66]

Re: Samsung UN55D6450UF - Lightning Damaged

Can you try using the back of the LCD panel (the large metal plate everything is secured on.) TV is switched on with screen lit up?

[ndoggfromhell]

Re: Samsung UN55D6450UF - Lightning Damaged

Screen on with the panel lit up. using the panel back as the ground, still getting all zeroes on the meter.

[tom66]

Re: Samsung UN55D6450UF - Lightning Damaged

OK, I need a closer picture around these two areas, try to capture at least as much as I have highlighted, but a bit more is fine.

[ndoggfromhell]

Re: Samsung UN55D6450UF - Lightning Damaged

First picture



Second Picture

[tom66]

Re: Samsung UN55D6450UF - Lightning Damaged

I was hoping I might have a schematic for the power board, no dice unfortunately...

You can see if the PSU is putting out good supply voltages. You have access to only the top row of pins from the top. Using the same method as for the T-con, black probe on chassis, red probe on each of these pins: pin 9 (#5 from mark "1") and pin 17 (#9 from mark "1"). What do you get?