Samsung ps50q96hd keeps blowing fuse

[Ice203]

Has a Samsung plasma that was making ticking noise so opened it up and
Noticed the fuse in centre of the power board was blown. So changed that and plugged TV back in and fuse popped again.
So. Unplugged all other boards and replaced fuse again.
It didn't blow.
So plugged main board in. And it went again.

So looking for ideas on what to check.

[tw2005]

Re: Samsung ps50q96hd keeps blowing fuse

Has a Samsung plasma that was making ticking noise so opened it up and
Noticed the fuse in centre of the power board was blown. So changed that and plugged TV back in and fuse popped again.
So. Unplugged all other boards and replaced fuse again.
It didn't blow.
So plugged main board in. And it went again.

So looking for ideas on what to check.

This is one of those TVs that it may be better bailing given the age and the cost of parts but i do believe there may be someone in the UK on ebay that has a very good price fixing some boards you could need.

Key failures in these are

Upper buffer, ymain

power board gets crack solders on the FETs for Va and Vs supplies, can randomly shutdown as a pre-warning, reflow fixes.

Where you are most likely at now is the power board has already blown, those FETs are shorted and bang goes the fuse.

the clicking would have been the relays endlessly cycling.

reasonable chance the ymain and upper buffer are shot too.

i have similar model here , same boards, upper buffer blown chps and shorted, ymain went with it, badly damaged also and just to top it off the PSu is shot just like yours by the sounds of it, Va and Vs fets blown, same fuse also blown, endless relay clicks and I have no plans to fix it unless santa claus does an air drop of the baords which are impossible to get or so expensive it would be crazy for the quality of this TV.

But, like i said, i did see very reasonable rebuild prices for the buffers on UK ebay some time this year

good luck should you choose this mission

[ReeceyBurger123]

Re: Samsung ps50q96hd keeps blowing fuse

Most common problem on these psu board is the all the fets on the middel heatsink blowing, you can find repair kits for this board on ebay for around £20.

[ReeceyBurger123]

Re: Samsung ps50q96hd keeps blowing fuse

Also cold solder joints on all the heatsinks is very common as well as bad caps, these board always need alot of work.

[Hamie]

Re: Samsung ps50q96hd keeps blowing fuse

As reecyburger says this is the kit you need.

http://m.ebay.co.uk/itm/281722783093

The reason it doesn't blow the fuse with the mainboard disconnect is because the mainboard turns the power supply on. Once you connect the mainboard it blows the secondary fuse.
Think the parts in this kit is for VA or VS. You won't get VS or VA voltage until the mainboard is connected.

[steviewonder]

Re: Samsung ps50q96hd keeps blowing fuse

Truly awful sets.i cringe at the sight of one.If you are lucky,and the ysus has no shorts presented to the psu,and the top buffer ic has no white blisters,then you may just need a psu kit,which consists of two 20 ohm resistors,two diodes,and two fets.Always check the transistors on the the sub board nearby,and for good measure I always replace the MC33067p i.c. Even then,things may not be straightforward..Good luck !.

[steviewonder]

Re: Samsung ps50q96hd keeps blowing fuse

four 20 ohm resistors...oops.

[ReeceyBurger123]

Re: Samsung ps50q96hd keeps blowing fuse

Truly awful sets.i cringe at the sight of one.If you are lucky,and the ysus has no shorts presented to the psu,and the top buffer ic has no white blisters,then you may just need a psu kit,which consists of two 20 ohm resistors,two diodes,and two fets.Always check the transistors on the the sub board nearby,and for good measure I always replace the MC33067p i.c. Even then,things may not be straightforward..Good luck !.

Totally agree Stevie the ysus's are nightmares when they blow and for the psus well they are just crap anyway. I have made a youtube video on one I repaired but for the 42" version its uploading now.

[ReeceyBurger123]

Re: Samsung ps50q96hd keeps blowing fuse

Here is the link to the video of the one I repaired https://www.youtube.com/watch?v=EUOg...ature=youtu.be
The one in the video is the 42" version but the exact same psu. I had to replace and repair the following:
Primary fets used arctic silver 5 as thermal paste
Fuse next to fets 4a 250v
5vstby diodes (check before replaing)
Mc Chip that is mounted on the heat sink next to the fets
Replaced all capacitors apart from primary's
Resoldered every device mounted on a heat sink and alot of other devices
You must check all of the following before calling it safe to plug in

[Ice203]

Re: Samsung ps50q96hd keeps blowing fuse

Installed the repair kit today.
Plugged TV in and BANG
SOMETHING in board went with massive bang.
So pushed TV aside for another day.
Thxs for advise every one. Will wait and but a smashed on for few quid and hope power boards ok

[ReeceyBurger123]

Re: Samsung ps50q96hd keeps blowing fuse

Bet it was the fets again did you change the mc chip and the diodes I replaced showing in my video ?