Samsung 5065W Will Not Power Up

[danieltx]

Hello,

I'm a first time reader/poster and I'm looking for some knowledge...

My HLN5065W will not power up. I "Frankensteined" it from an HLN437WX which had a bad power supply. The 5065 had a bad lamp when I bought it from a guy on CraigsList. Once I threw in my 437's lamp, I noticed a dead pixel too close to the center for my viewing pleasure. (I do wonder if the guy broke the lamp to hide the dead pixel. Hehe.) I did some part swapping to get rid of the white spot on my new-to-me Samsung:

1. Figuring that it was a mirror issue on the chip, I installed the 437's Engine Assembly/DMD Drive sub-frame (for lack of a better term) into the 5065. I noticed that the projector lens was different, so I made sure to use the 5065's lens in the 437's Engine Assembly.
2. A DVI cable connects the DMD drive to the digital PCB in the 5065, but the 437 had a different connector. For this reason, I had to bring the Digital PCB from the 437 into the 5065.
3. The Control PCB (PWR, VOL, CHANNEL) also had a different connector, so the 437's was brought into the 5065, as well.

Of the five major components of the 5065, only the Power PCB remains. All others are from my 437.

When I powered up the TV, everything worked, but the picture was about +/- 3" higher than it should be, cutting a huge chunk off the top and leaving a swath of black across the bottom. The next day (today) I corrected the picture by loosening the two screws on the right side of the DMD Drive and adjusting its position. When I turned on the TV, the picture was perfect. I tighteed the adjustment screws, slid the Power and Main PCBs back in, and attached all of the back plastic. The TV has not come back on since. I'm no electrical engineer, but I've been reading the service manual for help. Currently, when I press the power button, nothing happens at all.


1. The back cover safety switch is taped closed.
2. I've used the wiring diagram to check and re-check all connectors
3. I checked the CN802 cable. On terminals 1-2-3, I got only .5 VDC, when it should be 5VDC. 4-5 should be 12VDC, but I got a reading of 0. These voltages did not change a bit when the power button was pressed.
4. I'm getting 118.6 VAC from the AC cord and the same from the 3-pin connector from the Line Filter to the Power PCB.
5. I understand that the ballast should be receiving 380 VDC from CN803, but I'm only getting 1.47 VDC. Again, pressing the Power button causes no change.


My conclusion is that the Power PCB needs to be replaced, but that was the same thing that went bad on my HLN437WX, so I'm questioning whether lightning would strike twice so close together. I'm reluctant to pay another $130 or so on this project without getting someone else's opinion. (Especially when I'm $100 into this already, and $400 can get me a newer, used Samsung 5065W.) Is there anything else I should check?


Thanks in advance for any help,

Daniel

[grayfox]

wow i dont know where to begin... as a fellow tech, let me begin by saying this is admirable work!