For the techies out there ....
When I increased the refresh rate on my HTPC to near the top end of the specs for my Sony 1292 (I don't remember the rate, but it is within the 1292's range), it displays it for a while, then one of the six horizontal output damping diodes fails shorted, and the projector shuts itself down.
The first time, it was one of the smaller ones, D23, a DFC15TR (there are five of these in parallel).
After I replaced it with an NTE506, the projector ran for hours, displaying 1080i from my DTC-100.
Tonight, I set her back onto the computer's output, muted the picture, and went away for an hour. When I came back, she was shut down again, with the same old error #02, "Horizontal Stop". This time, it was D1, the sole DD82RC, that had shorted.
All six of these diodes are in parallel. Does anyone know of any other component whose failure could cause these diodes to poop out like this?
On the other hand, would it make sense to just put more of them in parallel to better handle the load?
Here's a portion of the schematic:
These are on the 'E' board, hanging off the collectors of Q7 and Q8, the main horizontal output transistors. The schematic doesn't show it, but IMHO the other end of all the diodes *has* to be going to ground.
Puzzled,
Paul
http://www.cooldog.com/images/1292eBrd4.jpg
When I increased the refresh rate on my HTPC to near the top end of the specs for my Sony 1292 (I don't remember the rate, but it is within the 1292's range), it displays it for a while, then one of the six horizontal output damping diodes fails shorted, and the projector shuts itself down.
The first time, it was one of the smaller ones, D23, a DFC15TR (there are five of these in parallel).
After I replaced it with an NTE506, the projector ran for hours, displaying 1080i from my DTC-100.
Tonight, I set her back onto the computer's output, muted the picture, and went away for an hour. When I came back, she was shut down again, with the same old error #02, "Horizontal Stop". This time, it was D1, the sole DD82RC, that had shorted.
All six of these diodes are in parallel. Does anyone know of any other component whose failure could cause these diodes to poop out like this?
On the other hand, would it make sense to just put more of them in parallel to better handle the load?
Here's a portion of the schematic:
These are on the 'E' board, hanging off the collectors of Q7 and Q8, the main horizontal output transistors. The schematic doesn't show it, but IMHO the other end of all the diodes *has* to be going to ground.
Puzzled,
Paul