37pfl7605h/12 power supply

[petehall347]

Re: 37pfl7605h/12 power supply

it will look short in circuit .. you have to at least remove the solder from one middle leg to test it

[dick_barton]

Re: 37pfl7605h/12 power supply

Data sheet
https://datasheetspdf.com/pdf-file/1...Ltd/D4SBL20U/1

[budm]

Re: 37pfl7605h/12 power supply

Those two pins of the bridge rectifier will show as shorted circuit because they are connected to the winding of the transformer which has very low DC resistance.
You need to remove the bridge rectifier to be able to test it properly.

[storexxm]

Re: 37pfl7605h/12 power supply

GUYS GUYS GUYS !
I just put this stupid thing on power.. the bridge retifier where the burnt area was, lighned up and burnt the whole area again.. the fuse is still good... when i put power in again nothing hapend... so i am 100% sure the thing is broken.

ANY idea what i need to buy.. ?
the numbers are total useless

[budm]

Re: 37pfl7605h/12 power supply

So did you clean up those solder joints of that bridge rectifier and re-solder them before applying the power?

[UPSENGINEER]

Re: 37pfl7605h/12 power supply

What were the results when you checked those two mosfets on the heatsink alongside the blue capacitor.
What is written on that capacitor?

thats a y cap

[storexxm]

Re: 37pfl7605h/12 power supply

So did you clean up those solder joints of that bridge rectifier and re-solder them before applying the power?

Yes... but the yellow thing blowed up... :/
again like it seems

do you have an idea how i can find it to buy ?

[budm]

Re: 37pfl7605h/12 power supply

GUYS GUYS GUYS !
I just put this stupid thing on power.. the bridge retifier where the burnt area was, lighned up and burnt the whole area again.. the fuse is still good... when i put power in again nothing hapend... so i am 100% sure the thing is broken.

ANY idea what i need to buy.. ?
the numbers are total useless

The BD1 bridge rectifier with the burnt pins are in the cold side of the circuit, that yellow PFC inductor is in the PFC circuit which is in the hot side of the circuit.
BTW, did it burn up the minute you plug the AC plug into the wall outlet or after you hit the power switch?

[storexxm]

Re: 37pfl7605h/12 power supply

the yellow PFC inductor just burnt out when i plugged the power in...
didnt press anything... fuse is fine...
guess there is no chance to buy another yellow PFC inductor ?

[budm]

Re: 37pfl7605h/12 power supply

https://www.badcaps.net/forum/attach...2&d=1603391855

Can I see the bottom side of the board where the PFC inductor is?
That PFC section is not activated until the power switch is turned on and PS-ON is sent from the main board..

[storexxm]

Re: 37pfl7605h/12 power supply

hmm.. this tv has a seperate power switch on bottom on the back...
i only plugged in two things.. the 230V power cord and the TV power switch... the plugged in and the yellow pfc burnt out...

damn i read the only thing to do is to build your own coil (

[budm]

Re: 37pfl7605h/12 power supply

That is the same OLD picture from before and I do not see burnt section around that PFC inductor.
How about new closed up pictures of the PFC inductor legs that are soldered to the board?
Also pictures of the re-soldered of the BD1legs.
Show us NEW pictures!

[storexxm]

Re: 37pfl7605h/12 power supply

sorry-´
NOW the blue capacitor burnt !

[budm]

Re: 37pfl7605h/12 power supply

That is where the burnt comes from, the snubber cap for the PFC MOSFET right next to the blue cap, not from PFC inductor..

BTW, I look at your post #13:
The blue one says:
471k
1kv
Measured 15k-20k ohm

The cap should show as open circuit. Was that resistance reading done in circuit or off the board?

[storexxm]

Re: 37pfl7605h/12 power supply

That is where the burnt comes from, the snubber cap for the PFC MOSFET right next to the blue cap, not from PFC inductor..

BTW, I look at your post #13:
The blue one says:
471k
1kv
Measured 15k-20k ohm

The cap should show as open circuit. Was that resistance reading done in circuit or off the board?

i measured the blue cap in circuit.

Hmm.... i will solder it out now...
but is it okay to say the problem is on the hot side in this area... ?

[budm]

Re: 37pfl7605h/12 power supply

At this point we are hoping it is bad snubber cap failure only.
You need to verify that R613 is still OK, same for the PFC MOSFET.
The new cap should be rated at lest 2KV, it is commonly failed cap in other power supplies as well.
Ceramic cap failure mode is leaky or short circuit.

[storexxm]

Re: 37pfl7605h/12 power supply

R613 is still very very low.. 0,3 Ohm.. like before... i think i cant measure the mosfet in circuit... only leg 1 to 3 i got stable measures... 1-2 and 2-3 is alway changing when measuring-

[budm]

Re: 37pfl7605h/12 power supply

R613 is fine, it is not damaged when the cap shorted out, it is the current sensing resistor connected to the Source pin of the PFC MOSFET so more likely it the MOSFET is OK too.

[budm]

Re: 37pfl7605h/12 power supply

https://www.badcaps.net/forum/attach...8&d=1603398209,
The soldering on the transformer pin to the right does not look that good.
I would resolder all the bridge rectifier pins and the transformer pins.

[storexxm]

Re: 37pfl7605h/12 power supply

i put in a new blue rubber cap...
everything is working again.
Seems like i had great luck nothing else took damage.
thanks to all !