PN43D490A1DXZA power supply broke?

[weiliz]

hello experts.
alright guys..this time i am giving this tv another try.
edit: forgot to mention..my tv has power red light but no picture...it keeps blinking red. with the error indicated by the logicboard.

when i plug out the Y sus board the logic board maintains a stable light.
should it should be either X or Y board fault right?
it turns out i was wrong. i proceed to measure every possible voltage on the SMPS board. and i found that
both of my Vs dropped from like 110+ to about 10V when i powered on the unit.
and voltage of my Va is inconsistent in 10V+

https://imgur.com/a/syJ5wNm

standby voltage and other dc5v are fine

additional informations


https://imgur.com/a/B9lijxQ
it is likely i will need a new board


videos for referencing:https://imgur.com/a/Rq4gDzz

[tom66]

Unlikely to be power board if Vs is present, even if dropping. Control board will shut down power board if there is a fault.

To test properly you would need to disconnect control board and main board from power board, then jumper VS ON to 5V and PS ON to GND to force the rails on. if they are steady without any board connected your power board should be OK.

[weiliz]

Originally Posted by tom66

Unlikely to be power board if Vs is present, even if dropping. Control board will shut down power board if there is a fault.

To test properly you would need to disconnect control board and main board from power board, then jumper VS ON to 5V and PS ON to GND to force the rails on. if they are steady without any board connected your power board should be OK.

PS ON to GND give me 5.276V
then i jump VS to A5V keep tripping, i dont know where u mean the 5V( tested the one power to main board)
P.s: they are tested without any board.

[weiliz]

so does this means its narrow down to ysus or xsus fault?

[tvtimmy]

Its most likely your xsus is bad. There are repair kits for it. Watch the shopjimmy video of the repair.

[weiliz]

Originally Posted by tvtimmy

Its most likely your xsus is bad. There are repair kits for it. Watch the shopjimmy video of the repair.

when i unplug the xsus ( if you mean x is the small one) leaving the ysus connected to the power SMPS...the logic board is still blinking error...( its a trial and error)
what i am sure is it is one of those 2 board but i dont know which
i would like an idea how to test the small one individually..
i am resort to buy the whole board and change it.

[weiliz]

with reference to the pic

unplugCN5003-CNXX--leaving y sus--blinking error
unplug CN804-CN5000--blinking stops and stable green light
and more importantly theres a clock ticking sound..which may be caused by the relay.i am not sure about it.

[weiliz]

hello guys i have doubled check the voltages on my power board (SMPS)
other board disconnected.(including main board and logic)
whats shocking is that Va,Vs and VScan are all have near 0V in dc
and in Ac, Vs=10.14v, Va=6.15V and Vsc=4.3mv


ysus idisconnect
Vs=5.795Ac dc voltage=dropping from 168V decreasing
Va=4.4mv decreasing dc voltage= dropping from 10.14V decreasing

Xsus disconnect
Vs=6.535VAc Vdc=0.121V
Va=5.935VAc Vdc=0.034V
Vscan(dc)=0.045V

is the SMPS shorted?
how i test it: place one point on the test points(Vs,Va,VScan) and other grounded to tv chassis.

however doing connection test smps on the output connector to ysus
Vs=206V
Vs=206V
Va=53V

as from ysus to xsus(output connector)
Vs=0.148V
Vs=0.14V.

i am pretty much confused.
if you need any more information i am willing to provide that.

[tom66]

Originally Posted by weiliz

PS ON to GND give me 5.276V
then i jump VS to A5V keep tripping, i dont know where u mean the 5V( tested the one power to main board)
P.s: they are tested without any board.

VS ON not VS!!! very bad if you jump to VS will destroy your power board.

VS ON needs to go to STBY 5V and PS ON to GND needs to be jumpered as well
Both control board and main board should be unplugged.

TVtimmy is correct that X-main is likely fault as it is common on this model, but do this check before.

[tvtimmy]

Watch this video. It is for a d450 but it is close enough to yours.
https://youtu.be/ovnw8BrsQnY

[weiliz]

Originally Posted by tvtimmy

Watch this video. It is for a d450 but it is close enough to yours.
https://youtu.be/ovnw8BrsQnY

the thing is when i unplugged the xsus board from ysus board, the clicking and logic error code is still there.
so should i get a x or ysus at this point?
note: unplugging the xsus from ysus doesnt give me any pics or sounds, still the old clicky .

[weiliz]

hello anyone?

[tvtimmy]

You will have to check the igbt and fets on the ysus, and check the y buffer board for shorts. Plenty of videos on how to do it. Also, search pn43d430,450,and 490 in the search section. Theres lots of help there.

[weiliz]

Originally Posted by tvtimmy

You will have to check the igbt and fets on the ysus, and check the y buffer board for shorts. Plenty of videos on how to do it. Also, search pn43d430,450,and 490 in the search section. Theres lots of help there.

so you telling that ysus are faulty right?
i dont want to change the components, as the fault might return
i will change the whole yboard

[tvtimmy]

I cant be sure because I dont have.the tv in front of me to test. Doing the tests will determine witch boards to replace. You can throw boards at it and not find it running untill you change the last one left. And theres no guarantee the ones you will buy are in working order. Its your call.

[weiliz]

i was wondering is there any way to test the x main individually since its power source comes from y main.....
tested the voltage of ymain it went very wrong with Vsc=-0.015V
and i test the ouput voltage from ysus connector to the xsus it doesnt add up.

[weiliz]

here is the connector

[weiliz]

same exact system as this https://www.youtube.com/watch?v=wmJenmz9vro
will also need to check the y buffer board, any ideas would be appreciated.

update: by using this https://www.youtube.com/watch?v=3Oq2MsU0XOQ
managed to check my y buyffer board and there appears to be no shorts, with 798ohms at some
however, people said its better to replace both ysus and ybuffer, any insight on this is appreciated.

[weiliz]

tps shorted, should be y board failure

[weiliz]

any opinions?