|
Hello everyone. My Panasonic NV FS90 VCR (PAL version) is having a problem whose cause I can't pinpoint. The other day, after twenty minutes of playback, the TV picture began to be affected by whitish horizontal stripes, varying in thickness, moving vertically. After a few more minutes, the horizontal image began to distort until it became intermittent and then disappeared completely, leaving a black screen. During this entire problem, the audio remained perfectly audible. Now the VCR no longer outputs any image (a black screen), while the audio from cassettes is perfectly audible. I've owned this machine since 1993, and after considerable effort, I managed to restore full functionality two years ago, managing to resolve, thanks in part to this forum, all the endemic defects that plague this Panasonic series. Basically, after replacing the entire head drum with an original Pana model, I replaced the capacitors on the SUB LUMINANCE/CHROMINANCE C.B.A. boards, the 1H DELAY CCD PACK C.B.A., the infamous C3311 on the LUMINANCE & CHROMINANCE PACK C.B.A. board, the four cursed SMDs on the VEFH05BT board that were blinding the S-VHS cassettes, and all the electrolytic capacitors inside the power supply. After all this work, the VTR has always worked fine for these two years, until this new defect whose origin I can't identify (I had basically already changed everything that usually breaks this recorder). At present, after checking the situation, I have found that my recorder does not play any video (black screen) from VHS/S-VHS cassettes through the SCART/RCA/Y-C/RF antenna outputs (leaving only the audio) while it continues to regularly record the audio-video signals from the line inputs (obviously playing those recordings on other VTRs). Even in simple transit (i.e. without recording tape) the incoming video signals do not pass to the output anywhere (the screen remains black). Only through the antenna connection (from the RF output) does the "test signal" of the two vertical white lines appear on the monitor (activated by the appropriate button on the back). Finally, when connecting the CVBS output to a Sony SB V3000 matrix, the orange LED that indicates the arrival of a composite signal remains off, while connecting the S-VIDEO output turns on the green LED (indicating that the matrix is receiving a video stream), but in both cases the screen remains black. I checked the solder joints on the main board, especially the board containing the RCA/SCART connections on the back, but I found no cracks. Now, having already replaced everything I knew to be causing the problem, I can't figure out what the hell is preventing the video signal from coming out from any type of connection. Could someone please give me some guidance on which board might be causing the problem and how to fix it? Thanks in advance.
|
