Dyp-42w2plus bn44-00194a

[flocko]

have this 50" Samsung come in with red standby light will not power on, checked power board and 5v standby is good and PS-on is 4.6v when in standby and goes low when power button on remote is pressed but relay fail to click,have pulled the board and put 680ohm resistor from PS-on to grd still no relay click started pulling and replacing caps,but getting nowhere fast any one had this with this board, it also looks to have been worked on in the past

[flocko]

Re: Dyp-42w2plus bn44-00194a

Has anyone seen any of the VIPer 22A primary switcher chip go bad on these boards, have not looked up the pin out for it but will check tomorrow and see if it tests out

[budm]

Re: Dyp-42w2plus bn44-00194a

Since you have 5VSTBY, that means the VIPER22 is working, you need to check the circuit around QB803, QB804, ICB802.

[Ltank]

Re: Dyp-42w2plus bn44-00194a

How low of a dvc when it drops? Does it go low enough? Q402 is not turning on. If circuit was working properly Q402 has a .7vdc drop.
LVT817B has a .7vdc drop leaving 3.6 vdc at anode of optoisolator. With 3.6vdc on anode and 4.6vdc on base of Q402 the transistor is not turning on and the led part of the optoisolator is reverse biased; therefore it too is turned off.
Try jumpering a low to grouund through a 500 ohm reisistor to the base of Q402. It should turn on both the transistor and thhe optoisolator. It aperars that
this set turns on with a active low not a high.

[budm]

Re: Dyp-42w2plus bn44-00194a

QB402 is for the UV-Reset, do you mean Q401 (is normally ON) which when PS_ON pin is grounded, the Collector will rise up and allow 5V to get to the LED in Opto PCB803S/A?

[flocko]

Re: Dyp-42w2plus bn44-00194a

Thanks guys for the input, Will have a look at the voltage reg ICB 803 and check transistors in and around it tomorrow

[Ltank]

Re: Dyp-42w2plus bn44-00194a

My Mistake I miss read it. I thought it said PS-on but what I see now is VS-on. I was on page 4 lower right corner when I made the mistake

[capricorn64]

Re: Dyp-42w2plus bn44-00194a

Hoping someone can help, I have pulled the power board from my Samsung tv, as I keep getting a clicking from the relays on the hot side of the board which is a DYP-42W2PLUS , 220V input supply, I have checked all the caps and all seem to fine . When I disconnect the plug from the CN801 port the clicking stops, I get 4.86V at the standby but nothing else 12v measurement non existent , I also get no readings from Vs205 or Va63.
Now I am assuming that a voltage regulator has gone down ,but I have no idea where to start looking for the fault if anyone has any ideas as to where I should be looking I would be most grateful, thanks in advance guys .......Steve

[flocko]

Re: Dyp-42w2plus bn44-00194a

Hi you need to test power supply out of he set with the mains connected you should have the 5v stby on the bottom right connector on pin 1, if you have that by making Ps on pin 4 Low to grd that will bring the relay in and give all voltages apart from Vs , to bring in Vs voltage jump Vs on pin 2 to 5v stby pin 1 with 500 ohm resistor. I hope this helps , the fault I had was that the relay would not come in when Ps on was made low the problem was tracked down to a fault relay coil the relay was replaced and fault was no more Flocko

[capricorn64]

Re: Dyp-42w2plus bn44-00194a

Thanks Flocko I will give it a try I think I understand what you mean !!!

[capricorn64]

Re: Dyp-42w2plus bn44-00194a

I have done what you advised ps on to grd which activated the relay (clicked on ) but turned of straight away so I am surmising that I could possibly have a relay problem aswell as voltages at pin 8 and 9 which are D5.3V are only reading -.250v would I be correct in my assumption ??

[budm]

Re: Dyp-42w2plus bn44-00194a

Ground the PS_ON and then check the VCC_P (for RL802S) and VCC_S (for RL801S) DC Voltages which are for driving the relay coils to see if they are steady, use the negative leg of the main filter cap for meter ground ref. points. See page 1 of the SCH.

[capricorn64]

Re: Dyp-42w2plus bn44-00194a

Thank you budm I will give this a try.

[flocko]

Re: Dyp-42w2plus bn44-00194a

I would look at all the soldering on the back of the board for cold joints as these board do have lot of problems with these , I do hope you have also checked the fuses? if you don't find and cold /dry joints then we need to start testing for shorted FETs Flocko

[capricorn64]

Re: Dyp-42w2plus bn44-00194a

Hi guys
The saga continues......I have changed out the relays for brand new ones, I now have a strong 5v at standby which is encouraging....or is it ,at the d5.3v its reading .756v so I guess I have a problem with the fets, trouble is I seem to be doing a lot of guessing.......

[Neelix]

Re: Dyp-42w2plus bn44-00194a

You get any 12V_OUT or 18V_Amp voltage? If not, you get any voltage at pin 15(VCC) of ICX801?

[flocko]

Re: Dyp-42w2plus bn44-00194a

Are you now saying that the relay clicks on and stays on when you ground PS -on (pin 4)? before you were saying it come in then went off.

[capricorn64]

Re: Dyp-42w2plus bn44-00194a

Neelix
I have checked voltage at pin 15(VCC) and all I am getting is -0.06V , getting nothing at 12V_OUT or at 18V_AMP !!

Flocko
Still getting the relays switching on and then going off straight away when I ground PS - on !!

Pretty flummoxed now ?

[budm]

Re: Dyp-42w2plus bn44-00194a

Neelix
I have checked voltage at pin 15(VCC) and all I am getting is -0.06V , getting nothing at 12V_OUT or at 18V_AMP !!

Flocko
Still getting the relays switching on and then going off straight away when I ground PS - on !!

Pretty flummoxed now ?

You are not going to get any Boosted PFC Voltage, 5.3V, 12V, 18V_AMP until you can get those two relays to stay on. If you look at the diagram:
Those two relays get their voltage from the standby power supply AUX winding TB801S, the Voltage is then fed through switched QB803, ICB802 (regulator), QB804 they are turned on when the opto OCB803S is turned on the PS_ON signal.
So, do you have steady STD_5V? Did you check the voltages at VCC_L, VCC_P, VCC_S that I suggested you to test? see post 12 and see the schematic to get more understanding how it works.

[flocko]

Re: Dyp-42w2plus bn44-00194a

Just a thought you are keeping PS-on grounded not just flashing it ?it need to be held to ground all the time Flocko