Hi there.
The background of this 22" unit is as follows. When I got it there was a classic 2 secs to black problem. Screen image was totally fine at this point.
I was able to pinpoint the problem to CCFL inverter which had one of its secondaries messed up and did not turn on one of the backlight tube pairs. Found a replacement at eBay, ordered, replaced and this time both tube pairs worked, but still 2 secs to black. I left the screen alone for quite some time as I was busy with other things. When I got back to business, I had also built four CFL test tubes to help find backlight problems for the future cases. I tried to run the display with CFLs and it worked! (well, at least the backlight issue was gone based on ~ 10 second test run, didn't take a peek at the actual image on the screen here) Further testing revealed something wrong with one of the tube pairs. Fortunately I had a used replacement part lying around, which I installed. Once the panel was reassembled after swapping the tube, I tried to power the display on and wtf!? The image is all distorted, having this sort of vertical pouring down going on. Also the entire power circuitry goes into a weird accelerating oscillation mode after turned on for a couple of seconds (see the youtube video link). Disconnecting backlights from power PCB has no effect on the oscillation. Disconnecting the display signal cable from between the panel and controller PCB does make difference - no more oscillation. For what it's worth, the oscillation is visible on the line voltage circuitry area, scoped that.
I wonder if I have accidentally damaged the sensitive panel circuitry during dissassembly/reassembly for the CCFL swapping. I tried to handle the panel very delicately and visual inspection does not reveal cut traces but who knows... The only thing I've done to electronics on purpose is swapping the CCFL inverter, nothing else.
A service manual might help a bit. Unfortunately I haven't been able to find one online.
I don't really know where to go from here. Obviously the problem is associated with whatever electronics are responsible for creating the image. Any help is much appreciated.
What the standard 'Check signal cable' image should look like: http://support-us.samsung.com/cyber/...mo.co.kr&sep=|
What the image looks now / turning on the display / oscillation problem: http://www.youtube.com/watch?v=bhDJZZzUZCM
The background of this 22" unit is as follows. When I got it there was a classic 2 secs to black problem. Screen image was totally fine at this point.
I was able to pinpoint the problem to CCFL inverter which had one of its secondaries messed up and did not turn on one of the backlight tube pairs. Found a replacement at eBay, ordered, replaced and this time both tube pairs worked, but still 2 secs to black. I left the screen alone for quite some time as I was busy with other things. When I got back to business, I had also built four CFL test tubes to help find backlight problems for the future cases. I tried to run the display with CFLs and it worked! (well, at least the backlight issue was gone based on ~ 10 second test run, didn't take a peek at the actual image on the screen here) Further testing revealed something wrong with one of the tube pairs. Fortunately I had a used replacement part lying around, which I installed. Once the panel was reassembled after swapping the tube, I tried to power the display on and wtf!? The image is all distorted, having this sort of vertical pouring down going on. Also the entire power circuitry goes into a weird accelerating oscillation mode after turned on for a couple of seconds (see the youtube video link). Disconnecting backlights from power PCB has no effect on the oscillation. Disconnecting the display signal cable from between the panel and controller PCB does make difference - no more oscillation. For what it's worth, the oscillation is visible on the line voltage circuitry area, scoped that.
I wonder if I have accidentally damaged the sensitive panel circuitry during dissassembly/reassembly for the CCFL swapping. I tried to handle the panel very delicately and visual inspection does not reveal cut traces but who knows... The only thing I've done to electronics on purpose is swapping the CCFL inverter, nothing else.
A service manual might help a bit. Unfortunately I haven't been able to find one online.
I don't really know where to go from here. Obviously the problem is associated with whatever electronics are responsible for creating the image. Any help is much appreciated.
What the standard 'Check signal cable' image should look like: http://support-us.samsung.com/cyber/...mo.co.kr&sep=|
What the image looks now / turning on the display / oscillation problem: http://www.youtube.com/watch?v=bhDJZZzUZCM
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