Dyp-42w2plus bn44-00194a

[nogger]

Re: Dyp-42w2plus bn44-00194a

Capricorn64, we seem to have crossed in our posts, i just saw your last update.

10 ohms is what i would expect & you should have that across QX801/802 as well. This means your Vs tract with the QS801 & 802 transistors is almost certainly ok (although I'm a bit confused as i believe you said FS801S was blown which would indicate blown QS801/2).

Do the little FET test from my earllier post on all 4 FETs & i would expect the QS801/2 to work correctly & the QX801/2 not.

Nogger

Capricorn64 just had a thought, when you say you measured across the 2 outside legs do you mean on the FET itself, i am talking about on the board where the legs solder to (not the FET itself)

[capricorn64]

Re: Dyp-42w2plus bn44-00194a

Capricorn64, we seem to have crossed in our posts, i just saw your last update.

10 ohms is what i would expect & you should have that across QX801/802 as well. This means your Vs tract with the QS801 & 802 transistors is almost certainly ok (although I'm a bit confused as i believe you said FS801S was blown which would indicate blown QS801/2).

Do the little FET test from my earllier post on all 4 FETs & i would expect the QS801/2 to work correctly & the QX801/2 not.

Nogger

Capricorn64 just had a thought, when you say you measured across the 2 outside legs do you mean on the FET itself, i am talking about on the board where the legs solder to (not the FET itself)

Hi Nogger
thanks for the guidance , I will have to get back to you with the readings on Wednesday as I am on a business trip tomorrow and not back till Wednesday, I think I may have written something down wrong , none of the fuses have blown they are all intact , I am thinking QX801 /802 are blown .
Steve

[chopper00]

Re: Dyp-42w2plus bn44-00194a

Hi, I Know this is an old thread but it is relevant. I have the same power supply with no STD_5v. The problem was no sign of life, took power supply out and visually inspected to find capacitor CX408 had split. Replaced with identical part. Powered up supply board to find no STD_5V. After reading this post have checked fuses, etc. I have 230v to DB801 but at FB801S I have 20.2V. At Viper22A I have 20.2V on all drains and 0.3V on VCC. Can someone please assist me in troubleshooting. Thanks

[flocko]

Re: Dyp-42w2plus bn44-00194a

Can you tell us what replacement you used for CX408 ? If you can follow on from DQ801+802 and check the in and out voltage to the ground of ICB802 as its looking likely that you problem is on the supply to the viper

[budm]

Re: Dyp-42w2plus bn44-00194a

Hi, I Know this is an old thread but it is relevant. I have the same power supply with no STD_5v. The problem was no sign of life, took power supply out and visually inspected to find capacitor CX408 had split. Replaced with identical part. Powered up supply board to find no STD_5V. After reading this post have checked fuses, etc. I have 230v to DB801 but at FB801S I have 20.2V. At Viper22A I have 20.2V on all drains and 0.3V on VCC. Can someone please assist me in troubleshooting. Thanks

How about good clear pictures of YOUR board, both top and the bottom side of the baord?

[chopper00]

Re: Dyp-42w2plus bn44-00194a

Thanks for that, quick update on my situation. I have managed to put the board down on my tweezers which has caused a short and blown NT801S (SCK20206LSY) Doh !!! I am having trouble trying to source a replacement. Could you please advise what characteristics i should match, I have several options in the UK but nothing identical. I guess i would need to replace this before testing any further ?

[budm]

Re: Dyp-42w2plus bn44-00194a

Ntc: SCK xx series spec.

[flocko]

Re: Dyp-42w2plus bn44-00194a

Hi these inrush thermistors have a habit of the shells cracking (still work but don't look to good on a refurbished P/B)so I change them often when I do my refurbish power supply work. I get them from China but you can get them on eBay item number:271685468228 that is the one I would use ,this guy has lot of handy parts and I use him myself , he all way seems to have what I want when I am in a need it now situation Flocko

[chopper00]

Re: Dyp-42w2plus bn44-00194a

Thanks for help, i have ordered the part you recommended Flocko, I have used these before for SMD components. Also happy with service. The thermistor went pop when it shorted so i know its u/s. Is there anything i could use to continue troubleshooting i.e 10/20 ohm resistor ?

[flocko]

Re: Dyp-42w2plus bn44-00194a

I though that your problem was with the 5vSTBY ? the inrush thermistor is over the power ON relay so will not affect 5vSTBY, the supply for this comes off before the relay, so the thermistor only comes into play when the relay clicks in from the PS ON signal to the relay coil.

[chopper00]

Re: Dyp-42w2plus bn44-00194a

Yes it is. Voltages in and out of the following components

Ground - Pin 2 of ICB802

IN OUT
DQ801 - 22acv 24dcv
DQ802 - 0 24dcv
RQ809 - 24dcv 10.9dcv
RQ803 - 10.9dcv 6dcv
RQ805 - 6dcv 1.4dcv

Also cap used was a 2200uf 16v 105degC (http://www.maplin.co.uk/p/2200f-16v-...apacitor-n12eb)

[chopper00]

Re: Dyp-42w2plus bn44-00194a

sorry cap used was a 1500uf 35v 105 degC (http://www.maplin.co.uk/p/1500f-35v-...apacitor-n11eb) dont know where the hell i got that other number from.

[flocko]

Re: Dyp-42w2plus bn44-00194a

first job you need to do is take out that cap and throw it as far as you can.Dont buy from Maplins these are general purpose Caps ,you need a low ESR cap, Panasonic FR/FM would be my choice but any low ESR will do. after you fit this and your replacement thermistor you may be good to go? when you are checking voltages on the Hot side of a power supply, use the negative leg of the large cap as ground and meter set to DC volts for all testing, when testing on secondary side use the metal work as negative ground (fixing screws) and meter set DC volts

[chopper00]

Re: Dyp-42w2plus bn44-00194a

Thanks for that info, i have ordered a EEUFM1V152L. I will update once parts arrive and have been fitted

[flocko]

Re: Dyp-42w2plus bn44-00194a

We could have got there faster if you had told me when I asked what replacement you had used for CX408, but we got there in the end ,and you have a little more knowledge for any future power board repairs Flocko

[chopper00]

Re: Dyp-42w2plus bn44-00194a

Hi there again, I have fitted the replacement thermistor and recommended capacitor but there is still no STD-5v, if I ground PS-ON (To turn on power supply) nothing happens ?

[budm]

Re: Dyp-42w2plus bn44-00194a

Hi there again, I have fitted the replacement thermistor and recommended capacitor but there is still no STD-5v, if I ground PS-ON (To turn on power supply) nothing happens ?

You do not ground the PS-ON pin to turn on the power supply, you use 500~1K resistor between PS-ON pin and the 5VSTBY pin to force on the power supply, and you MUST remove the PS-ON cable going back to the main board first.
BUT, since the STBY is not working so it is no use trying to force on the power supply, need more in depth troubleshooting of the STBY section.

[chopper00]

Re: Dyp-42w2plus bn44-00194a

Thank you, I was under the impression you grounded the PS-ON pin and used a resistor on the VS-ON pin. Also the power supply is on the bench until i can get and prove voltages.

[flocko]

Re: Dyp-42w2plus bn44-00194a

I would change all the caps for new low ESR ones, I thought the one you replaced was the 5v stby cap that normally goes (splits)but after looking the one you replaced is on the 5.3v rail, Budm is right you will not get the supply to start without first getting the 5v stby working, but you are right with the PSon to ground, with the main board cable removed from the supply and VSon to stby with a resistor, I always take the power board out to work on and just have the mains plugged in . I am guessing Budm though this was a LCD supply, I don't know why Samsung changed PSon ( high )on LCD and (low ) on plasma

[budm]

Re: Dyp-42w2plus bn44-00194a

Thank you, I was under the impression you grounded the PS-ON pin and used a resistor on the VS-ON pin. Also the power supply is on the bench until i can get and prove voltages.

OK, I found the BN44-00194A diagram, in this one you are correct that Grounding the PS-ON to turn on the power supply.
I am not sure this diagram is 100% accurate.