Lcd tv vs lightning strike vs repair

[CurrentBitesOnlyOnce]

Hi ppl,
i have a lcd tv which suffered lightning strike, red diode is on but you can not power on the tv it is not possible to switch it on. I did some work and i believe i have diagnosed it correctly. Board is TP.MS3463S.PB801 and main chip (they call it lcd chip but for me it is microcontroller or maybe microprocessor) is MSD3463GSA. Very soon as you plug it to the wall the chip gets hot maybe in a minute, i did some voltage checks and looks like all arround the pins the voltage is 3,4v suggesting internal short in the chip, also some voltages are missing for example 1.15 or 1.something v. Since markings on the diagram are poor and there are some abbreviations which i am not familiar of i am stuck and cant figure out what are the inputs and what are the outputs but i am pretty sure the chip is gone. I assume that most of 5v and 3.3v are voltage regulated power supply and those voltages of 1. and 0. v are probably outputs of a chip, am i right?
Looks like other stages are just fine there is power to the usb and hdmi ports, there is power out of the switcher looks like the levels are correct, so it looks like the chip itself is bad, but before i test the rest and change the chip eventually i need to know how hard is to change the chip?
I guess it has to be programmed?
Do you need special equipment?
Can you buy already preprogrammed chip for that specific board?
Can it be programmed on the board or has to be on the bench?
Help and advices are apprecieted.
Thanks.
P.S. since this is my first post here i hope is in right section.

 

[Nigel Goodwin]

Well you don't mention the make, the model, or even what country you're in? - but assuming it's a micro?, you would need to obtain one ready programmed from the TV manufacturer - there's not a hope at all that they would provide you with the code to program your own chip.

However, it's VERY, VERY likely that the chip isn't available, repairs to LCD TV's are almost entirely board replacements only, with most manufacturers no longer supplying even schematics to their service network.

I've had considerable experience repairing CRT TV's after lightning strikes - mostly for my own 'interest' - as all you can do for the customer is give them a write-off estimate for their insurance. You can't give them a repair estimate, without repairing it first - so the only option is a write-off estimate.

Anyway, here's how lightning repairs generally go:

1: Locate faulty IC, replace it - set still faulty.

2: Locate next faulty IC, replace it - set still faulty.

3: Locate next faulty IC, replace it - set still faulty.

(repeat as required): Locate next faulty IC, replace it - set still faulty.

xx: Set now works - CRT has been damaged by lightning (shadowmask deformed) - scrap set.

So while I've successfully repaired a few, the vast majority end up scrap, even if you manage to get them working at all. It helps if you have a scrap chassis, that you can remove chips from to replace the faulty ones, so you're only spending time and not money.

 

[CurrentBitesOnlyOnce]

Thanks for the reply.
Tv is either vox or samsung i can't rember but i can give you exact model if is really needed. That's why i gave number of the "motherboard", that board is used across variety of applications, the chip with the number in first post is used on those boards but i guess its a different programing or firmware on it from tv to tv. I don't even know what and if anything is on it. Chip is available through ebay but i am pretty sure it is not ready to be just soldered on the board. Also never been soldering that large chip, 200 pins. Schematic for the board is available and i am trying to fix the tv for myself. So my questions from the first post still need answers. Bassically if i can't swap a new chip in and if i can't buy preprogrammed one then i have to scrap the tv.
Waiting for further assistance.
Thanks.

 

[Visitor]

You can buy entire boards for many flat-panel TVs on eBay. But you might end up replacing the logic board and power supply board only to find the panel itself is busted.

 

[Nigel Goodwin]

As visitor says, you can often buy second hand boards on Ebay - and that's probably your best bet. A replacement chip would be completely useless, unless it's already programmed by the TV manufacturer for that EXACT set.

However, as he also said, the panel could be duff as well.

There's also the problem that the replacement board could be duff - often they are removed from sets with broken screens, so you'd think the boards would be OK. But not always so - the TV goes faulty, so they knock it over and smash the screen, then claim off their insurance - so you've got a set with a smashed scree, AND a faulty board inside.

 

[schmitt trigger]

Many years ago, I was involved into lighting strikes studies for a large TV and cable box manufacturer.
I can tell you right now that our ultimate goal was customer safety.
The circuit itself could, and most of the time would, be completely lost.
And that was ok as long as there were no injuries.

So I’ll join the chorus: if you want to repair the unit as a personal challenge, by all means do so.
OTOH, if the purpose is to save time and money, your money is better applicable towards a new set.

 

[unclejed613]

normal failures are usually one or a handful of components on a board, but lightning damage is usually many components on multiple boards.

 

[CurrentBitesOnlyOnce]

You ppl are awesome, i appreciate all your answers. You were of a great help. That's right, fixing this tv is a challenge and it is a process of learning. This set doesn't look to complicated, there is only two boards at the back, main board and the ethernet board. The main board is priced at the half what is worth the whole set so i guess since i can not change only the chip then it will make this a good source of a spare parts.

 

[Nigel Goodwin]

You ppl are awesome, i appreciate all your answers. You were of a great help. That's right, fixing this tv is a challenge and it is a process of learning. This set doesn't look to complicated, there is only two boards at the back, main board and the ethernet board. The main board is priced at the half what is worth the whole set so i guess since i can not change only the chip then it will make this a good source of a spare parts.

The most common failure on LCD sets is the screen - which (even if it's available - which is unlikely) costs more than a complete new set.

So, the screen (if it's undamaged) is fairly valuable - particularly because as well as the screens failing, they commonly get smashed as well (Wii controllers used to be a major cause!).

 

[CurrentBitesOnlyOnce]

Ok. Is there a way to check the screen? Like i said i have checked various voltage levels around the board and majority looks fine leading me to think the rest of the set is fine.

 

[Nigel Goodwin]

Ok. Is there a way to check the screen? Like i said i have checked various voltage levels around the board and majority looks fine leading me to think the rest of the set is fine.

Only by connecting it to a working set - voltages don't help a lot, unless supplies are missing. A lot of what goes on in an LCD TV are digital signals of numerous types.

 

[CurrentBitesOnlyOnce]

Thanks man. If i go for a used main board does it really have to be from a same tv (brand, model etc)?

 

[Nigel Goodwin]

Thanks man. If i go for a used main board does it really have to be from a same tv (brand, model etc)?

Obviously so - you 'may' be able to fit a board from a different size set that uses the same chassis - but this would most likely involve updating the software on the board, a process that you may not have access to, using a file you may not be able to obtain (it's likely to be service agents only).

 

[Nigel Goodwin]

I've just checked that PCB number, in the UK there are loads of adverts on Ebay for around £15, and listed as for a Baird TV.

Baird is just a badge, used by Supermarkets etc. on any cheap crap they can buy in - in this case it appears to be a UMC set.

So it's only a cheap crappy set anyway, of no great value even if repaired.

 

[CurrentBitesOnlyOnce]

I understand you and i am not concerned about the value of the tv. I think this tv was payed around 150e probably overpriced but it is like that. Like i said i really want to "FIX" it although i don't need it. The boards i've been looking for were around 50e, almost half the price. So this is what i was thinking about, change just the chip and get it fixed but you point me that this is not an option, next option is board but i am not gonna pay half the price of a new set just to find out that this one has more damage to it, but if i can get a cheap board why not to give it a try. But cheap boards are coming from different brands, so help me to understand something. If the board is the same number and let's guess main chip is the same too but the boards are coming from two different brands why the boards are not interchangeable?
All the rest on the tv are peripherals and outputs of the main board, so from my point of view if i get i board from a baird tv it should work in my tv, can be different menu on the tv, remote may not work but the tv should be operational, right? Did i got this completly wrong, went off of the tracks or maybe even crashed??

 

[Nigel Goodwin]

It depends on exactly how the sets are designed and manufactured, the board from another 'make' made by UMC 'might' be identical, and it might not - it could easily have completely different software.

One of the Ebay listing looks to be from a spares company, and they specifically listed the exact make and model that the board was for, and that it probably wouldn't work in anything else.

If you can get one cheap enough, then buy it and see what happens - if it doesn't work you can always resell it on Ebay.

I've never had any dealings with UMC sets, but I have with the more popular Vestel sets - and on those you can 'sometimes' swap boards between makes, but often there are enough differences that it doesn't work, particularly with the software (although when you compare boards from different models, you often see different components missing).

 

[CurrentBitesOnlyOnce]

Thanks man, i am glad i found this forum.