Hello,
I have read many of the posts here, that have helped me track down my problem.
As the title says, I have a vizio m470vse, with a dps-129dp power supply. I received it with a blown fuse. I tested the bridge (out of circuit) and it was ok (I think, but please tell me if I am wrong). The positive symbol is on the left and the negative is on the right. With the DMM set to 20m ohms and the negative lead on the positive (left) pin...positive lead to the first AC reads 2.10, 2nd ac reads 2.31, and the negative (right pin) reads 3.57. With the DMM in diode mode (reading in the same order and still the negative lead on the positive pin) I get .65, .653, and 1.545. No readings in the other direction.
It is printed on either side of the screw, like this...
LT 2229
KBJ 406G
I am not sure how that is supposed to be read.
Next, I tested the mosfets. There are 3 on this board. The first one tested bad and the other 2 seem a bit "iffy" so I decided to just replace them as well, since I have them off the board already and from what I have read about one making the others go bad.
My problem is that I can not determine what they are exactly. I did the "chalk trick" and I am able to read them, yet nowhere on the internet seems to recognize them. I tried chatting with digi-key, but they did not know either.
The one that is bad for sure has "k10a60dr", under the number is an X, then a 2B over in the corner (which an internet search does show a toshiba something, but I am not sure if that is it.).
The other 2 look similar, but they have "k4a60dar", then an X and 2:T printed on them. When I put these in the hfe slots, in my DMM, one registers at 130 and the other says 20. They register in the npn side. Starting with the far left pin; they are b, c, then e.
The first mosfet "k10a60dr" will not read in any of the npn or pnp slots. With that being said, I am not sure what type it is, other than bad (I get nothing in the hfe slots and I get a reading, no matter which pins are touched, on ohms and diode mode).
Physically, they all seem to be about the same size (3/8"x5/8") and the middle pin is longer than the outside pins. This leads me to think that the single is also npn, but that is only a guess, that I would not be willing to bet on. The "bad 1, is on its own heat-sink (about 1/4" larger than the other heat-sink), while the other 2 share 1 heat-sink. They are all 3 black with a "step" at the top. The only exposed metal on them, are the pins, the screw, and the heat-sink(with thermal paste). The screw goes straight through the "plastic", without a metal backing.
Digi-key chat said, that they could find something comparable, if I could provide them with the Voltage, current rating, package type, and transistor type. If it was not for one of the other posts here, I still would not even know what a mosfet was. As it is, I just barely understood how to test them, much less know how to find this info.
I have tried looking up a schematic, to no avail. Obviously, I could not find a data sheet, using the printed part numbers. I can find plenty of replacement boards for around $70, but I want to keep the price down as much as possible, plus I would like the satisfaction of fixing this board.
I would greatly appreciate any help, that could be offered. I am sorry that I do not have any pictures. I hope the description will suffice.
I have read many of the posts here, that have helped me track down my problem.
As the title says, I have a vizio m470vse, with a dps-129dp power supply. I received it with a blown fuse. I tested the bridge (out of circuit) and it was ok (I think, but please tell me if I am wrong). The positive symbol is on the left and the negative is on the right. With the DMM set to 20m ohms and the negative lead on the positive (left) pin...positive lead to the first AC reads 2.10, 2nd ac reads 2.31, and the negative (right pin) reads 3.57. With the DMM in diode mode (reading in the same order and still the negative lead on the positive pin) I get .65, .653, and 1.545. No readings in the other direction.
It is printed on either side of the screw, like this...
LT 2229
KBJ 406G
I am not sure how that is supposed to be read.
Next, I tested the mosfets. There are 3 on this board. The first one tested bad and the other 2 seem a bit "iffy" so I decided to just replace them as well, since I have them off the board already and from what I have read about one making the others go bad.
My problem is that I can not determine what they are exactly. I did the "chalk trick" and I am able to read them, yet nowhere on the internet seems to recognize them. I tried chatting with digi-key, but they did not know either.
The one that is bad for sure has "k10a60dr", under the number is an X, then a 2B over in the corner (which an internet search does show a toshiba something, but I am not sure if that is it.).
The other 2 look similar, but they have "k4a60dar", then an X and 2:T printed on them. When I put these in the hfe slots, in my DMM, one registers at 130 and the other says 20. They register in the npn side. Starting with the far left pin; they are b, c, then e.
The first mosfet "k10a60dr" will not read in any of the npn or pnp slots. With that being said, I am not sure what type it is, other than bad (I get nothing in the hfe slots and I get a reading, no matter which pins are touched, on ohms and diode mode).
Physically, they all seem to be about the same size (3/8"x5/8") and the middle pin is longer than the outside pins. This leads me to think that the single is also npn, but that is only a guess, that I would not be willing to bet on. The "bad 1, is on its own heat-sink (about 1/4" larger than the other heat-sink), while the other 2 share 1 heat-sink. They are all 3 black with a "step" at the top. The only exposed metal on them, are the pins, the screw, and the heat-sink(with thermal paste). The screw goes straight through the "plastic", without a metal backing.
Digi-key chat said, that they could find something comparable, if I could provide them with the Voltage, current rating, package type, and transistor type. If it was not for one of the other posts here, I still would not even know what a mosfet was. As it is, I just barely understood how to test them, much less know how to find this info.
I have tried looking up a schematic, to no avail. Obviously, I could not find a data sheet, using the printed part numbers. I can find plenty of replacement boards for around $70, but I want to keep the price down as much as possible, plus I would like the satisfaction of fixing this board.
I would greatly appreciate any help, that could be offered. I am sorry that I do not have any pictures. I hope the description will suffice.
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