Home |
Search |
Today's Posts |
|
Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
|
LinkBack | Thread Tools | Display Modes |
#1
|
|||
|
|||
JVC GD-V4200PZW Plasma strange issues
Hi there - I'm hoping someone here has some idea of what is going on
here. I've acquired a JVC GD-V4200PZW 42" plasma display cheaply, as it is ill, and the owner decided to throw it out without attempting to repair it... I've investigated the symptoms, and they are as follows: Upon initial powerup, with no connections, OSD works fine, all menus on OSD work fine, OSD looks fine... From this, I figure the actual display itself is fine. Upon connecting a composite video (or s-video) input, the resulting display is initially completely illegible, and has magenta streaks all over the place, dancing in a noiselike fashion. After a power cycle, the result is sometimes magenta streaks, sometimes cyan, sometimes yellow (which always seems to saturate to an entirely yellow display, rapidly). Most of the time, RG&B pixels are all on. Over time, the image gains some stability, however is completely useless as a display, as there is still a large amount of noise. If VGA is connected, the initial display will always be either green tinted, or normal colour. Power cycling brings about one or the other each time, however cycling through inputs tends to have less of an effect. The display is initially extremely unstable, however over time gains stability, and is covered in lines which almost look like the Moire effect, however these lines gradually become narrower, and tend towards the horizontal (initially, they are all over the shop, and kink). After ~1 hour of uptime, the image is fairly stable, however is still dominated by grey lines. After several more hours of uptime, black incursions begin to appear, flickering briefly, and taking the form of a line reaching across the screen, with a black 'ramp' up towards the line from below, on the left side of the screen. All pixels horizontally aligned with the 'ramp' are shifted accordingly with the ramp to the right. I've dismantled the unit, and have checked for dry joints, and for damaged capacitors (there are some *huge* electrolytics in there), however can't see anything obviously wrong - the time dependancy of the problems makes me suspect the capacitors, but I'm not sure... If anyone has any experience in this area at all, any info would be much appreciated! Cheers! Max |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
FS: Fine Woodworking Back Issues | Woodworking | |||
Sony Plasma Displaying Green Noise/Patches | Electronics Repair | |||
Why I don't have a plasma or LCD TV either | Electronics Repair | |||
SONY GDM-FW900 Brightness issues Strange! | Electronics Repair |