65js9000 power supply bn44-00818a

[thuss]

Re: 65js9000 power supply bn44-00818a

Will do thanks

[thuss]

Re: 65js9000 power supply bn44-00818a

Thanks for the diagram will check pin7 on the ic and the voltage on the transformers

[thuss]

Re: 65js9000 power supply bn44-00818a

The A5.3V comes from TS801CS, & B13V comes from TM801CS, It is TM901CS that supplies the Vdrv. So recheck that the ic is installed and soldered properly and check all the gate drive diodes & resistors for QM901CS & QM902CS, also check that the drive transformer TM903CS windings are not open. Also check CM906CS, if you don't have a cap checker, make sure the cap is not bulged, if it IS, it is likely open, it provides the ground return for the transformer.

Theres 16v on the yellow line at various jumpers. The transformers seem all fine. No voltages on tm901cs. On qm902cs centre pin no voltage whilst on qm901s centre pin 385v- will check and replace the mosfet again and check the surrounding components again. The cap is one of those blue square ones.

[R_J]

Re: 65js9000 power supply bn44-00818a

Thanks for the diagram will check pin7 on the ic and the voltage on the transformers

Don't check the voltage on the transformers, just check the resistance with an ohm meter to be sure the gate drive windings did not go open.

[thuss]

Re: 65js9000 power supply bn44-00818a

Don't check the voltage on the transformers, just check the resistance with an ohm meter to be sure the gate drive windings did not go open.

Yes theyre fine . There's no voltage on qm902cs - it seems fine. I think looking at the board you kindly attached that it provides power to the transformer

[R_J]

Re: 65js9000 power supply bn44-00818a

Yes theyre fine . There's no voltage on qm902cs - it seems fine. I think looking at the board you kindly attached that it provides power to the transformer

That's not really how it works, the mosfets gates are driven by high frequency (around 100khz). first QM901cs gets turned on and supplies the voltage to the transformer, then it gets turned Off and QM902CS turns On connecting the transformer to ground. This switching of the primary induces a current in the secondary, providing the Vdrv voltage.

If you can provide the voltages on the pins of the sem3110 it might help, be very careful not to short the pins of the ic.

[thuss]

Re: 65js9000 power supply bn44-00818a

[QUOTE=R_J;1049490]That's not really how it works, the mosfets gates are driven by high frequency (around 100khz). first QM901cs gets turned on and supplies the voltage to the transformer, then it gets turned Off and QM902CS turns On connecting the transformer to ground. This switching of the primary induces a current in the secondary, providing the Vdrv voltage.

If you can provide the voltages on the pins of the sem3110 it might help, be very careful not to short the pins of the ic.[/QUOTE


Unfortunately we didnt use a sem but a adp. Secod thing before we shorted the adp3110a out, pin 2 (in) even thought clearly connected/soldered to its pad didnt seem to be connected to anything in continuity? I just wish i could buy a psu

[R_J]

Re: 65js9000 power supply bn44-00818a

I wish you would have told me this in post #1, The ic you are using will not work. You need a SEM3110a

SEM3110a pinout
pin1 = DT
pin2 = RT
pin3 = OC
pin4 = SS
pin5 = GD2
pin6 = GND
pin7 = VCC
pin8 = GD1
If you still have the original sem3110a it could be ok. I have not tried this sub but a UCC25600 is supposed to work.

Pin 2 (RT) should have a resistor to ground (2.2k) and also be connected to PC903S through another resistor (330Ω) There could also be a 1.2k in series with a 1µf cap across the optocoupler.

[thuss]

Re: 65js9000 power supply bn44-00818a

I wish you would have told me this in post #1, The ic you are using will not work. You need a SEM3110a

SEM3110a pinout
pin1 = DT
pin2 = RT
pin3 = OC
pin4 = SSt
pin5 = GD2
pin6 = GND
pin7 = VCC
pin8 = GD1
If you still have the original sem3110a it could be ok. I have not tried this sub but a UCC25600 is supposed to work.

Pin 2 (RT) should have a resistor to ground (2.2k) and also be connected to PC903S through another resistor (330Ω) There could also be a 1.2k in series with a 1µf cap across the optocoupler.

Sorry was mentioned in post 21. My mate contacted
A main components supplier and they said it should be fine. Once again sorry for waating your time.

[R_J]

Re: 65js9000 power supply bn44-00818a

Sorry was mentioned in post 21. My mate contacted
A main components supplier and they said it should be fine. Once again sorry for waating your time.

Not to worry, my mistake I missed that it in post #21, There is no way that ic can work. Here is a similar circuit using the SEM3110A

[thuss]

Re: 65js9000 power supply bn44-00818a

Not to worry, my mistake I missed that it in post #21, There is no way that ic can work. Here is a similar circuit using the SEM3110A

Thanks - i think the psu is past repairing. Installed the old original :3110a and now when switched on it blows the house fuses.

All the psu fuses are fine but the bridge rectifier need to be removed and checked and the primary mosfets sre reading short.

We have bought components before from china and as someone did mention earlier the quality is hit and miss. The ucc25600 delivery date from our local reputable supplier is late 08/21. A replacement board would be cheaper. But thanks for everybody's help especially R.J thank you.

[thuss]

Re: 65js9000 power supply bn44-00818a

Thanks - i think the psu is past repairing. Installed the old original :3110a and now when switched on it blows the house fuses.

All the psu fuses are fine but the bridge rectifier need to be removed and checked and the primary mosfets sre reading short.

We have bought components before from china and as someone did mention earlier the quality is hit and miss. The ucc25600 delivery date from our local reputable supplier is late 08/21. A replacement board would be cheaper. But thanks for everybody's help especially R.J thank you.

But saying that will try again to fix with a ucc25600

[thuss]

Re: 65js9000 power supply bn44-00818a

I know this is an old thread but i was wondering if i can get some advice again . Got my hands on another faulty power supply with the same fault i.e the fuse was blown and the 4 mosfets k15a50d,irfi4410z were blown- replaced all 5 but this time it's blown only the two mosfets k15a50d.
The ic sem3110a was replaced with a new sem3110a ( took forever to arrive) just wondering anybody else has come across this and possibly a solution? Could it be the backlights or the led driver board any help would be really appreciated

It also blew the house fuse again but as far as i can tell nothing else on the board.