Samsung UE60F6300AKXXU....Dead

[Andyd1970]

Hi Guys,

Can you help? Have a Samsung UE60F6300AKXXU that is dead, taken back off and found fuse across mains input connector is blown, now I am sure it is not that simple or is it? only had things in past have the mains fuse blow and replaced it and it blows again as something else is pulling it down.

Can anyone suggest where to start on this PSU please? I have checked the diode and none of them are shorted.

Andy

[dskall]

Re: Samsung UE60F6300AKXXU....Dead

Check bridge rectifier. Better pictures of power board.

[Andyd1970]

Re: Samsung UE60F6300AKXXU....Dead

Images as requested, can you point me in the direction of the bridge rectifiers please.

[momaka]

Re: Samsung UE60F6300AKXXU....Dead

Bridge rectifier is component BD8015.

Using this picture as a reference...
https://www.badcaps.net/forum/attach...7&d=1513671851
... start at the lower left corner, go right just past the center, and then go slightly up. You should see BD8015 board designator right there. It is that 4-pin component with the pins labeled "- ~ ~ +" from top to bottom.

But really, this is not necessary to do right now. You have a burn mark on your board. Again using this picture as a reference...
https://www.badcaps.net/forum/attach...7&d=1513671851
... look at the heatsink (silver block of metal / radiator) on the right side of that picture: there is black sooth right where the white glue is and where you can see the board designators CP806 and QP802C5. If I had to guess, that's probably one of the APFC MOSFETs that has gone bad. So you will probably need to remove that heatsink in order to get to it.

Please post a picture of the underside (solder side) of the PSU, if possible.

[Andyd1970]

Re: Samsung UE60F6300AKXXU....Dead

Hi Guys, Sorry for delay. I have removed heatsink and the three MOSFET's do not seem to be blown, the blue cap near the middle one is slightly split and blacken, so is that the fault? or can a MOSFET blow but not actually blow up?

[vinceroger69]

Re: Samsung UE60F6300AKXXU....Dead

yes those capacitors can fail like that can you read the printing on the side of it so you can order a new one

[tom66]

Re: Samsung UE60F6300AKXXU....Dead

You should check the FETs are not shorted using a meter but those capacitors can and do fail. Samsung sets are somewhat notorious for it, as well.

[budm]

Re: Samsung UE60F6300AKXXU....Dead

Another failed snubber cap, go with 2KV replacement, the body is still intact so you should be able to read the capacitance value.

[Andyd1970]

Re: Samsung UE60F6300AKXXU....Dead

Hi,

This looks like a resistor? as it says R 221K 1KV on it?

If so I need a 221k that is rated at 1KV? or do I need to look for something else?

Thank you

[tom66]

Re: Samsung UE60F6300AKXXU....Dead

It's not a resistor.
221 = 220pF. (22 x 10^1)
K= tolerance code. In this case 10%

Use a 2kV (voltage rating) cap to reduce chance of future failure.

So you are looking for 220pF 2kV, tolerance 10% or better

[vinceroger69]

Re: Samsung UE60F6300AKXXU....Dead

https://www.ebay.co.uk/itm/10pF-10nF...QIwCGTItpeZ9BA

[Andyd1970]

Re: Samsung UE60F6300AKXXU....Dead

OK, great ordered the caps.

Testing the three MOSFETS...is it just as simple as putting meter across two pins and checking for no short circuit? only one of the only has two pins.

[vinceroger69]

Re: Samsung UE60F6300AKXXU....Dead

mosfet testing
https://www.utm.edu/staff/leeb/mostest.htm
the two legged device maybe a diode just test it in both directions

[Andyd1970]

Re: Samsung UE60F6300AKXXU....Dead

Hi Guys,

Fitted the tiny blue cap as per Tom's attached link from ebay, fitted it and replaced the 5.0A fuse on PSU and the TV now powers up OK

I guess that means it is fixed? but will test it for a few hours.

Thank you everyone for you help.

[Andyd1970]

Re: Samsung UE60F6300AKXXU....Dead

One quick question...

The fuse I just used a 5A 20MM quick blow fuse from Maplin and soldered wires to it and insulated the fuse in heat shrink as could not find the type soldered to the PSU, does it matter that I do not use the type that was fitted?

Sorry for all the questions.

[momaka]

Re: Samsung UE60F6300AKXXU....Dead

As long as the fuse is of the same current rating, type (slow blow or quick-acting), and voltage rating (or higher), the rest shouldn't matter.

[vinceroger69]

Re: Samsung UE60F6300AKXXU....Dead

as your power supply has the T before the amp marking it is a fast blow so you should be fine may also be worth adding some new heatsink compound on the mosfets/diode when you re assemble the heat sink as will save possible future overheating issues etc

[tom66]

Re: Samsung UE60F6300AKXXU....Dead

T is time delay, F is fast blow. Use time delay.

[vinceroger69]

Re: Samsung UE60F6300AKXXU....Dead

as your power supply has the T before the amp marking it is a fast blow so you should be fine may also be worth adding some new heatsink compound on the mosfets/diode when you re assemble the heat sink as will save possible future overheating issues etc

sorry i did read the page wrong now re reading it tom66 is right time delay
quote
Read the manufacturer's label, if it says fast or slow, the fuse type is as it is labeled. If it says F it means the fuse is a fast-blow, and if it says T or S it means it is a slow-blow. Other letters will indicate unique fuses for your specific device.
quote