JVC 32" Curved LED TV Model LT-32N376

[angelos]

Hi Guys,
I have this all in one TV board of which i can't source the board or any parts on the board. I have narrowed the fault to a 6 pin SMD Device which i assume is 2 transistors in one package. One of the transistors is shorted out. Is there any advice as to what i can do? The SMD markings are "6000A" and "GW004", i cant find any info on it otherwise i would add transistors externally if i knew the specs. Any help anyone?
I added a picture of the board encircling the suspected component in red.

[budm]

Re: JVC 32" Curved LED TV Model LT-32N376

That is a SMPS IC.
What is the TV not doing, no Voltages on the cold side at all?

[angelos]

Re: JVC 32" Curved LED TV Model LT-32N376

Yes Budm,
The IC must be shorted because when it is in circuit i get weird low ohms values across some smd caps. As far as i can surmise it probably is two transistors in one package. Anyway, the outputs are dead and there is no short measured on the outputs.

Now here is the kicker, Someone suggested i import from china one of those modules that you can install. How it works is you remove the shorted parts on the SMPS primary and remove the primary output mosfet. Then this little pcb is installed with its 4 wires which you solder on specified places on the primary. This takes over the function of the primary PSU. What else must i do if parts are kept secret, no datasheet nothing. This works if you have no short on th secondary side of the PSU.

[angelos]

Re: JVC 32" Curved LED TV Model LT-32N376

bump

[budm]

Re: JVC 32" Curved LED TV Model LT-32N376

Exanple of 6-pin SMPS IC.
https://cdn.badcaps-static.com/pdfs/...64be03ba09.pdf
https://blog.nxp.com/power-managemen...ps-controllers
If I were you I would start tracing the pins of the IC to see where they go to. I would use Ohm meter to try to locate GND pin first, then Check the connection from the GATE pin of the power MOSFET to see which pin it is connected to (it may have resistror between GATE and the IC pin, etc.
BTW, in your picture, it looks like some parts close to the IC got hot.

[angelos]

Re: JVC 32" Curved LED TV Model LT-32N376

Thanks Budm,
I will trace out the design and will check where this leads me. As for parts getting hot, no i did not notice that except that i did remove 2 components and resolder them and perhaps that is what you see in the picture.
I will get back to you on this one.

Regards

[angelos]

Re: JVC 32" Curved LED TV Model LT-32N376

Hi Budm,
I finally got time to trace this PSU out. Please have a look at it. It does not match that AN11675 IC you mentioned. I am still in the dark here.

[budm]

Re: JVC 32" Curved LED TV Model LT-32N376

What I gave is just an example of the 6-pin SMPS IC.

[angelos]

Re: JVC 32" Curved LED TV Model LT-32N376

Yes, i know that you gave an example but what can one do with a unknown component where the internet has no mention of it and i have hit a road block now.
Anybody been down that route?

[budm]

Re: JVC 32" Curved LED TV Model LT-32N376

The LD7535 (see page 3 for pinout looks to be really close to what you have, recheck pin 4 (CS) to see if it has connection (may be via resistor) to the Source pin of the Power MOSFET (see page 9, 10, and 13) .
BTW, what is the designator of that IC? ICxxx?, Uxxx?
Also looks very close to NCP1250.
You can only do so much without the schematic or the spec sheet of the components.

[angelos]

Re: JVC 32" Curved LED TV Model LT-32N376

That is so true, Budm. I was thinking of importing that module i spoke of. It replaces the primary of the PSU. If i am going to wait months to receive stock from china i can just as well get the whole section.
I chatted with some guys on Facebook from India who change out the primary side and they do it successfully. If my client is willing to wait i will give it a try.