ledn42k15p not turn on

[topng]

hi my led tv do not turn on i have blue led but it dont start
i buy new psu and still no power up .
the switch not Respondsץ
any help .


psu : rsag7.820.2264

display : rsag7.820.4207 ver.a

[tom66]

Re: ledn42k15p not turn on

Can you supply pictures of the circuit boards in the TV?

[topng]

Re: ledn42k15p not turn on

i will take a pic later

but here is the psu schamtic
http://www.520101.com/html/hisense/21541513.html


the main board is the problem
I found some capacitors short

[topng]

Re: ledn42k15p not turn on

here is the main


here is the psu

[tom66]

Re: ledn42k15p not turn on

Have you checked you are getting the right supply voltages from the power supply?

[multimeter]

Re: ledn42k15p not turn on

you may need to check for ripple on the power supply capacitors though,because they may be sending a little to much AC through wrecking the main board caps,not known them to fail much.infact i havent found one lol

[tom66]

Re: ledn42k15p not turn on

You've never had a bad main board? I've had several and done 1/10th the TVs you have. Must be odd luck.

[topng]

Re: ledn42k15p not turn on

hi tom and multimeter
i find that {mst6e48rhs-lf-sj} is making shortes
whan i take it off from the board
i saw no short in the circuit

did it a Programmable chip or can be replaceable one on one ?

[tom66]

Re: ledn42k15p not turn on

It looks like it has external flash chip, so you do not need to reprogram it. It will run code from the flash chip instead.

Beware though, it's rare for a CPU to fail. So you have to ask why? it could be because of a bad voltage regulator or excessive supply voltage. I had one board fail and put 5V onto the 3.3V standby of micro, after that, it came back dead short, only got really hot.

[topng]

Re: ledn42k15p not turn on

hi Tom thanks for the help
in my opinion 'when burned satellite receiver it took the TV with him
it was connected via hdmi .

[tom66]

Re: ledn42k15p not turn on

That could easily do it, looks to be not much protection for HDMI.

[topng]

Re: ledn42k15p not turn on

ן removed all voltage regulators from the circuit and checked them
With external power supply

[topng]

Re: ledn42k15p not turn on

i will look for where I can buy this and update

if you know a shop that can quickly send'd love to hear

Thanks

[tom66]

Re: ledn42k15p not turn on

I found one guy but minimum order 30 ICs. Maybe you can negotiate for just one.
http://www.aliexpress.com/item/4-new...037153637.html

[multimeter]

Re: ledn42k15p not turn on

You've never had a bad main board? I've had several and done 1/10th the TVs you have. Must be odd luck.

i mean the smd caps on a mainboard,yes had plenty of mainboards gone bad!,hate working on them,lots have been EEPROM faults ,especially the vestals with the plug in EEPROMS ,yuck!

[topng]

Re: ledn42k15p not turn on

hi tom & multimeter

replaceing the chip {mst6e48rhs-lf-sj} solved the problem..

[tribble]

Re: ledn42k15p not turn on

hi guys havin the exact same problem. thought about consulting with you before replacing the chip (which I can't locate on the Board btw). could this be caused be something else?