Samsung PS50Q97HDX went BANG

[AJS]

So ive owned a Samsung PS50Q97HDX from new for about 7-8 years. I was watching T.V the other day and it made a loud bang and that was that. It now wont turn on it just makes a clicking sound like its going to turn on but it wont.

I have opened it up and I found 2 parts that seemed to be the problem as they had split in half so i replaced them both http://www.ebay.co.uk/itm/201017986430 with these, but the problem still persists. Can any one suggest what else I can try ? Or should I call it a day?

I have no experience in this area so I will appologise now if I have to ask you to explain things that are very simple.

The circuit board that was affected was the centre one in the picture the only one that isnt green.

Any help is appreciated

Cheers AJS

[Alastair E]

Re: Samsung PS50Q97HDX went BANG

Often, when these fail--they take the driver devices with them as well--So, you fit a couple of new ones to be instantly destroyed by the faulty drivers....

Theres some SM components on the board itself as well as on that small sub-board behind the heatsink and the chip on there too. They'll all need replacing,--Its a tedious job, as I recall--there's two SM diodes on the board and 5 or 6 transistors as well as the IC on that sub-board.

The main cause of these failing is dry-joints initially on the two MOSFETS that have blown apart.

That board is called, The PSU. Check on it, there's a number BN44-00xxx If you are not too confident in replacing SM (Surface-Mount) then best get an entire PSU from a good supplier......
When fitting new PSU, Check the Voltages Vs and Va, re-set to that quoted on the sticker on rear of the metal-work of the plasma panel.

[AJS]

Re: Samsung PS50Q97HDX went BANG

Sorry I forgot to say after I replaced the parts and started it up it didnt make a bang again and the parts look ok visually. Do you think they will need replacing again ?

Also do you have a link for the other parts I would need? are they expensive ?

[Alastair E]

Re: Samsung PS50Q97HDX went BANG

The supply fuse to the ones that have popped--Did you replace it?
(Hopefully not!)

I THINK the transistors are BC858--But you'll have to check, my memory aint great (Anymore!) and its over a year since I did one of those.

Parts aint hugely expensive, prolly get a complete kit of parts for around £25,(Check fleagay with PSU Number) but as I said--the devices are VERY small, and if you are not confident in working with SM then I would seriously get some practice in on some old stuff first, or recommend a complete power-supply......

[AJS]

Re: Samsung PS50Q97HDX went BANG

The only thing I have touched are the 2 MOSFETS I will have a look on e-bay for the other bits , or I might just see if there is someone i can send it off too.

Thanks for the help Alastair E

[sordids999]

Re: Samsung PS50Q97HDX went BANG

https://www.badcaps.net/forum/showthread.php?t=39514

not sure if this helps but i fixed mine also

[AJS]

Re: Samsung PS50Q97HDX went BANG

Nice one Thanks.

[RJARRRPCGP]

Re: Samsung PS50Q97HDX went BANG

So ive owned a Samsung PS50Q97HDX from new for about 7-8 years. I was watching T.V the other day and it made a loud bang and that was that. It now wont turn on it just makes a clicking sound like its going to turn on but it wont.

I have opened it up and I found 2 parts that seemed to be the problem as they had split in half so i replaced them both http://www.ebay.co.uk/itm/201017986430 with these, but the problem still persists. Can any one suggest what else I can try ? Or should I call it a day?

I have no experience in this area so I will appologise now if I have to ask you to explain things that are very simple.

The circuit board that was affected was the centre one in the picture the only one that isnt green.

Any help is appreciated

Cheers AJS

I just saw a "KM" cap. They make me wonder, because they reportedly often go bad without bulging or leaking! Some of the KMs tested were real out of spec when they visibly looked fine! Possibly the worst caps on the planet for going bad without bulging or leaking!