Can the power supply board burn/damage the main board? (Samsung TV)

[vladusername]

I have a Samsung TV UA40F5000AR that doesn't turn on but has the red light on.
When I checked the internet, the problem seems to be either in the main board or the power supply board.
The technician came and thought the problem was in the main board, so he replaced it with a new one. The TV turned on, so he turned it off and closed the back cover and returned it to its place (since it was fixed) but when he tried to turn it on once again, it didn't.
He said that the problem is in the power supply board, and it burnt/totally damaged the new main board.
So my question is... Is this be true? Can the power supply board totally damage a new main board within few seconds?

 

[jay32267]

I do a lot of work on this sort of thing, and yes it's possible.

...but if I suspected the PSU had a problem, I would have checked the PSU voltages before I went and hooked up the main board so I didn't ruin it.

 

[vladusername]

I do a lot of work on this sort of thing, and yes it's possible.

...but if I suspected the PSU had a problem, I would have checked the PSU voltages before I went and hooked up the main board so I didn't ruin it.

Is there a way to find out that it really affected the main board? Like.. would I find a burnt area or something?
And is this highly possible to happen? Or does the technician bluff so he doesn't look inexperienced?

 

[hang-the-9]

Not sure why you would have someone repair a 40" TV these days, the cost of a new one with a new warranty is maybe $200 for a good model, and you can find them used for like $100. You can get 43-58" 1080 and 4k new sets for a bit over $300 also, money much better spend than on repairing a cheap small TV if you need to pay someone to do the work.

 

[jay32267]

"Is there a way to find out that it really affected the main board? Like.. would I find a burnt area or something?
And is this highly possible to happen? Or does the technician bluff so he doesn't look inexperienced? "

Sometimes you will see a burnt area....but not always.

...and it's very possible that it happened...but as I said....I would have thought the tech would have checked the PSU before he hooked to it.

.....and maybe....as you said....he's bluffing because he doesn't know what he's doing.