Samsung UE40C6000RWXXN clicking power board issue

[sepper]

Hello,

I have a Samsung UE40C6000RWXXN. It makes the clicking sound and won't boot.
It's 100% sure it's the powerboard because I have an almost identical other samsung tv and I switched the powerboard and it's working.
But I can't find the issue on the faulty powerboard . It's a PD46AF1E_ZSM. I get 5.3v on my STB. If I connect it to the logic board the PS_ON voltage will switch between 0 and 3.3v. So I bridged
STB to the PS_ON but I don't get 12v on the other outputs... I replaced some capacitors but I think they were still ok.

I don't know where to look now. I have a multi meter and tried to check some fuses and they look ok on the board. Any tip where to look now?

Friendly regards,

Seppe

[dick_barton]

Re: Samsung UE40C6000RWXXN clicking power board issue

Power supply schematic available at:-



Do you hear the relay click in when you power up.

What DC voltage is there with your meter probes connected to each of the two legs of CP804 when switched on.

Have you checked FM801S, NT811S & NT812

[sepper]

Re: Samsung UE40C6000RWXXN clicking power board issue

Power supply schematic available at:-



Do you hear the relay click in when you power up.

What DC voltage is there with your meter probes connected to each of the two legs of CP804 when switched on.

Have you checked FM801S, NT811S & NT812

The relay clicks 1 time so that's working
I get 388V on my CP804 and CP803
FM801s should be fine... Is this a ceramic fuse diode?

My NT811S and NT812 give an open circuit.

NT812 changes from 20 omh to 10 omh when I heat it up.
NT811S changes 2.8 ohm to 1.5 when I heat it up.

(FYI: I didn't remove them from the circuit... But power was off)

I think this is ok according to the datasheets?

[dick_barton]

Re: Samsung UE40C6000RWXXN clicking power board issue

The voltage across the capacitor looks fine.
The relay clicking in is also good.
The resistances of NT812 & NT811S are also good.

You don't have the 12V but do you have any other voltages missing, eg Vamp_18V

Can you visually inspect CM813 and measure its value if you can.

[sepper]

Re: Samsung UE40C6000RWXXN clicking power board issue

The voltage across the capacitor looks fine.
The relay clicking in is also good.
The resistances of NT812 & NT811S are also good.

You don't have the 12V but do you have any other voltages missing, eg Vamp_18V

I get 2.65V on my 5.3v outputs, and I get 0V on my Vamp and 12V outputs

If I measure on CM813 just DC with my multi meter on both pins I get 0V. Visually I don't really see something. Or should I measure it differently?

[dick_barton]

Re: Samsung UE40C6000RWXXN clicking power board issue

With the mainboard disconnected and the STB5.2 connected to Power On/Off via a 1K resistor, what voltages do you have on the pins of QM802 & QM803 using the negative leg of CP803 as your ground lead for your meter.

[sepper]

Re: Samsung UE40C6000RWXXN clicking power board issue

With the mainboard disconnected and the STB5.2 connected to Power On/Off via a 1K resistor, what voltages do you have on the pins of QM802 & QM803 using the negative leg of CP803 as your ground lead for your meter.

Ok I get 0V on all the pins...
But I made a rookie mistake and I fucked up my ceramic fuses in the beginning of the circuit... I accidentally touched both legs of the CP803 with my crocodile clamp. So I need to find new ones

[dick_barton]

Re: Samsung UE40C6000RWXXN clicking power board issue

Don't worry. I think we've all made that mistake.

[sepper]

Re: Samsung UE40C6000RWXXN clicking power board issue

Don't worry. I think we've all made that mistake.

Can I replace them with with same value T6.3AH 250v ? Or do they have to be the ceramic ones.

[dick_barton]

Re: Samsung UE40C6000RWXXN clicking power board issue

It's best to replace like for like. If there was a short circuit on your supply then glass fuses can shatter and splatter glass everywhere. Ceramic fuses do not shatter when subjected to a short circuit.

[sepper]

Re: Samsung UE40C6000RWXXN clicking power board issue

It's best to replace like for like. If there was a short circuit on your supply then glass fuses can shatter and splatter glass everywhere. Ceramic fuses do not shatter when subjected to a short circuit.

Ok I will order them hopefully I have them by tomorrow. Does the 0V on the QM803 and QM802 give any insights? Maybe I can order new parts together

[dick_barton]

Re: Samsung UE40C6000RWXXN clicking power board issue

I suspect they are OK but would be interested in whether or not they are being driven by UCC25600 driver chip.

What you could do is check all the diodes using your meter in diode mode which are around that part of the circuit and also the resistors with your meter set to ohms while waiting for the replacement fuses.

Is CM807 top starting to bulge?

[sepper]

Re: Samsung UE40C6000RWXXN clicking power board issue

I suspect they are OK but would be interested in whether or not they are being driven by UCC25600 driver chip.

What you could do is check all the diodes using your meter in diode mode which are around that part of the circuit and also the resistors with your meter set to ohms while waiting for the replacement fuses.

Is CM807 top starting to bulge?

Ok I will check them.

This fuses are ok right? Need to order at least 25 So I can still blow a lot of them

MC000850 https://cdn.badcaps-static.com/pdfs/...39ee2a5f66.pdf

CM807 doesn't look like it's bulging

[dick_barton]

Re: Samsung UE40C6000RWXXN clicking power board issue

Is there a small electrical shop near you where you could purchase a few ceramic fuses.

If there's a T in from of the fuse rating eg T6.3AH then it's time delay fuse at 6.3Amp and not quick blow.
Is the fuse that blew 20mm in length and did it have legs attached?

This seems to be the style for the two 6.3A fuses next to the mains input on the board
http://uk.farnell.com/littelfuse/047...lay/dp/2762060

Also available on ebay

[sepper]

Re: Samsung UE40C6000RWXXN clicking power board issue

Is there a small electrical shop near you where you could purchase a few ceramic fuses.

If there's a T in from of the fuse rating eg T6.3AH then it's time delay fuse at 6.3Amp and not quick blow.
Is the fuse that blew 20mm in length and did it have legs attached?

This seems to be the style for the two 6.3A fuses next to the mains input on the board
http://uk.farnell.com/littelfuse/047...lay/dp/2762060

Available fro ebay
http://www.ebay.com/itm/2-x-6-3A-Cer...IAAOSwr81US7Cl

Ok so I need a time delay fuse. Does it matter if its greater value then 250V like 500V as long as its 6.3A or does it have to be 250V?

I can buy this one https://cdn.badcaps-static.com/pdfs/...6f0416fd01.pdf MC000837 and some decent fuse holder If I can make it fit. The other ones are out of stock Still looking for a decent shop in my city.

[dick_barton]

Re: Samsung UE40C6000RWXXN clicking power board issue

As long as it's rated at T6.3A and 250V (or greater voltage) then that would be fine.

[sepper]

Re: Samsung UE40C6000RWXXN clicking power board issue

I suspect they are OK but would be interested in whether or not they are being driven by UCC25600 driver chip.

What you could do is check all the diodes using your meter in diode mode which are around that part of the circuit and also the resistors with your meter set to ohms while waiting for the replacement fuses.

Is CM807 top starting to bulge?

I checked all the diodes and resistors I think they are ok. And I hope so... God dam SMD

Now I play the waiting game until tomorrow for my fuses. Hopefully I didn't blow up more. Already thanks for your help.

[sepper]

Re: Samsung UE40C6000RWXXN clicking power board issue

As long as it's rated at T6.3A and 250V (or greater voltage) then that would be fine.

Back up and running 25 fuses to blow now. Something more I can investigate?

[dick_barton]

Re: Samsung UE40C6000RWXXN clicking power board issue

With the mainboard disconnected and the STB5.2 connected to Power On/Off via a 1K resistor and using the negative leg of CP803 as your ground lead for your meter (but be careful not to short it again) you could very carefully measure the DC voltages on ICM802.

[sepper]

Re: Samsung UE40C6000RWXXN clicking power board issue

With the mainboard disconnected and the STB5.2 connected to Power On/Off via a 1K resistor and using the negative leg of CP803 as your ground lead for your meter (but be careful not to short it again) you could very carefully measure the DC voltages on ICM802.

I measured on the CM806 + leg and CP803 - leg. And I get 13V.