The thing that is confusing me is that for you to get the 12v then the 24v should be present.. You shouldn't be able to get one without the other as the switching circuit uses both.
Seems to me as if something may be shorted closed somewhere.
budm is the one to trace circuits so will leave him to this.
test q201
the middle leg is not used
red left leg black right leg =112
red on middle leg black on right=short or closed
black on left leg red on right=112
black on middle leg red on right=short or closed
the middle leg is not attached its clip off so
now test with black on top or where it solder to borad
black to point on top of borad red left leg =112
black to point on top of borad red middle leg=short or closed
black to point on top of borad red right leg= short or closed
red to point on top of borad wher it is solder to black to left leg=116
red to point on top of borad wher it is solder to black to middle leg=short or closed
red to point on top of borad wher it is solder to black to right leg= short or closed
The middle leg is connected internally to the big tab which is Drain pin, looking at it with big tab up: left pin is Gate, Middle/tab is Drain, Right pin is Source.
OK, your readings do not make sense to me based on what I see on the board.
You need to check the Voltages on the two legs of those filter caps for 24V feeding the S pin, output at the D pin.
This is the best I can do from looking at the pictures of the board.
ok the caps feeding the s pin in not there an same with output to d pin
well some volts are there it reads for an sec then zero
the test from early was without power on dioide mode
But you still have 12V at the 12V output pins?
Without power on, do mean TV is not plugged into the outlet?
Are you using the Chassis for the black probe and the board is not mounted to the chassis?
It does not make sense to me for not having 24V at the 24V output pins and 0 Volt on the D pin with force on resistor applied.
Please get the P/N of the IC for the 12V Buck converter.
Also do the resistance test between the D pin of the MOSFET and ALL 8 legs of the 12V Buck converter IC to verify that the MOSFET is in deed feeding the Voltage to the IC to create 12V.
nr8910
sk 412
926t
is what is on the ic202
black on drain tab an red on pins I get this
3.83 3.56 9.33 3.59
1 1 1 1
1 1 1 1
1.29 2.20 0.00 open
from back side of pb
an when I plug this pb with nothing plug in or jump I get 12 volts an 3.5
I thought that is should only have 3.5 until ps to trun on
I think it is NR891D.
So far I cannot find the pin out or spec sheet for it. http://www.aliexpress.com/store/prod...851702653.html
I really do not expect the 12VDC to be present until PS-ON is applied, so I am not really sure what is going on yet.
But is does look like one pin is connected to the D pin of the MOSFET.
well more info if this help i bought an pb from ebay an main from shop jimmy
the pb i got from ebay does the same thing when i got this tv it had no stand by led so i frist said ok pb so order one put it in an same thing no light so look at it more close the 3.5 goes there the main so i said maybe main is bad lol order one from shop jimmy
nope still same thing no led stand by but it has volts going to it then i said hmm lets try here at badcaps an now we are here i am no expert but can do more then the averge joe lol i have fix coultless tvs an this one has got me down
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