Post by Deleted on Oct 17, 2015 13:15:31 GMT -5
When looking at my own screenpictures I saw that there was a discolouring on the left and right side. After trouble shooting it turned out that the focus board had a problem and the blue dynamic focus did not work.
Among my spare boards there was a VDC 2005 focusboard. However it turned out that the dynamic focus for red did not work on this board.
My third board had serious drifting problems so I had to repair one of the two broken boards.
It was easy to see that the cap C108 looked exploded on the top. Also I soon saw that two fusable resistors where black and broken R116 and R110. Simple replacing them did not fix it so I had to search further.
With the multimeter on diode I compared the reading of Q101 till Q105 and it was clear that almost all of them had died. Only Q102 turned out to be good. So I replaced all of them from the board where blue was broken and checked with the multimeter and all seemed fine. Finally i checked that electrolytic capacitor C108 and it read 0 uF. So now it was clear to me. The -24V line had peaked because the cap was broken and that had burned all those transistors.
After testing within 5 minutes the fusable resistor R118 died (+24V line). Because I could not find a broken part I replaced thinking that it probable was almost broken to start with and needed a little push to break. Testing again ant untill now the board seems good again!
In repairing this board I used a lot of what I learned here thinking about asking questions but it was never necessarily. Just thought I would report the results for others.
Among my spare boards there was a VDC 2005 focusboard. However it turned out that the dynamic focus for red did not work on this board.
My third board had serious drifting problems so I had to repair one of the two broken boards.
It was easy to see that the cap C108 looked exploded on the top. Also I soon saw that two fusable resistors where black and broken R116 and R110. Simple replacing them did not fix it so I had to search further.
With the multimeter on diode I compared the reading of Q101 till Q105 and it was clear that almost all of them had died. Only Q102 turned out to be good. So I replaced all of them from the board where blue was broken and checked with the multimeter and all seemed fine. Finally i checked that electrolytic capacitor C108 and it read 0 uF. So now it was clear to me. The -24V line had peaked because the cap was broken and that had burned all those transistors.
After testing within 5 minutes the fusable resistor R118 died (+24V line). Because I could not find a broken part I replaced thinking that it probable was almost broken to start with and needed a little push to break. Testing again ant untill now the board seems good again!
In repairing this board I used a lot of what I learned here thinking about asking questions but it was never necessarily. Just thought I would report the results for others.
