Dyp-42w2plus bn44-00194a

[chopper00]

Re: Dyp-42w2plus bn44-00194a

Am I correct in thinking that TB801S is the supply transformer for the 5v circuitry ?

[chopper00]

Re: Dyp-42w2plus bn44-00194a

With ground on one of the large caps i am getting 265dvc on drains of viper 22a and 7.8vdc on vcc. but no voltage around RB806, DB808 or ICB802, and with ground on screw fixing no voltage around TB801s Pins 9 and 12

[budm]

Re: Dyp-42w2plus bn44-00194a

265VDC between the two legs of the main filter cap? What is your AC incoming line Voltage?
When you work in the primary side of the circuit, the GND REF. for the meter will be the negative leg of the main filter cap, not the chassis.
120AC USA = ABOUT 165~170VDC on the filter cap before PFC Voltage booster circuit is on
230V EURO = 330VDC.

[chopper00]

Re: Dyp-42w2plus bn44-00194a

"265VDC between the two legs of the main filter cap?" which capacitor number are you refering to ?

[budm]

Re: Dyp-42w2plus bn44-00194a

The main filter cap is the largest cap on the board with 450VDC rating on it, see the diagram.
Your post" With ground on one of the large caps i am getting 265dvc on drains of viper 22a and 7.8vdc on vcc" What large cap and which leg of the cap?

[chopper00]

Re: Dyp-42w2plus bn44-00194a

With my black lead of multimeter on negative lead of CB801 and my red lead on viper DRAINS I get 265dcv, with red lead on Pin 6 of TB801s i get 265dcv, and red lead on viper VCC I get 7.8dcv. Which I assume are all points on the HOT side. With my black lead on the screw fixing/chassis and red lead on pins 9 or 12 on the TB801s I get 0dcv which I assume is the COLD side.

[budm]

Re: Dyp-42w2plus bn44-00194a

265VDC is not right at all, what is you AC line Voltage? How about between the two legs of the cap?

[flocko]

Re: Dyp-42w2plus bn44-00194a

read post #53 I told you there the correct way to test voltages check RB806 this shows to be a 1ohm 1/2 w fused resistor, also tell us what you have across ZDB803

[chopper00]

Re: Dyp-42w2plus bn44-00194a

AC Line voltage is 241acv, across cap is 262dcv. RB806 checks out ok and across ZDB803 is 7.8dcv.

[flocko]

Re: Dyp-42w2plus bn44-00194a

The viper Vdd has a shutdown- start up voltage range between 8v -14v , so 7.8v is shutdown and should be up around 13-15v,the main cap 262v is low should be about 330v, do you have a ESR meter to check that cap

[chopper00]

Re: Dyp-42w2plus bn44-00194a

No, I dont have an ESR meter, can i take it out and test it ?

[flocko]

Re: Dyp-42w2plus bn44-00194a

Without a ESR meter there is no way of testing all you could do is replace or see if it has vented but to be honest we don't see many that are bad

[chopper00]

Re: Dyp-42w2plus bn44-00194a

I have taken the cap out and there are some visible signs of a problem. What do you think ?

[flocko]

Re: Dyp-42w2plus bn44-00194a

hard to see but looks to be leaking on the + leg and round the bottom seal,best to change them all if you find one has leaked or vented the rest wont be far behind. but don't find very often you have to change big cap

[chopper00]

Re: Dyp-42w2plus bn44-00194a

****SUCCESS**** I have replaced the filter cap and the power supply is now working. I have ordered the remaining cap replacements and will do them when they arrive. Thank you for all your help on this, I now have a good idea on the 5v STD circuitry.

[flocko]

Re: Dyp-42w2plus bn44-00194a

Well done happy to help Flocko

[Richard1982]

Re: Dyp-42w2plus bn44-00194a

Hi, sorry to revive an old post but it's about the same problem I'm having. I have a Damsung Plasma with BN44-00194A power supply.
TV symptoms - on plugging in the 240v the blue/white LED on the front of the TV comes on. Pressing power produces no startup tone, the blue light goes out and no standby red light. Pressing remote control buttons causes blue/white LED to flash but nothing else. No clicks, noises etc.

Removing the power supply from the TV isn't a problem. I understand that my first check should be for 5v standby, produced by VIPER22A. Looking at the schematic that would be the negative leg of the largest cap and any of the drains (pins 5-8) on ICB801S. Is this correct?

[Richard1982]

Re: Dyp-42w2plus bn44-00194a

Ok. Got power supply working. When I plug in the mains I now get a beep and the white light on the front gives a slow flash. Still nothing on the screen though. Help?