I was given a sony kp-57hw40 that supposedly had a bad flyback, as per the previous owner's research on the # of flashes of the status light. Since it was in storage for >1 yr, I felt comfortable changing out the flyback with a brand new one I was able to obtain. When I did the job and turned it on, there were a few blue flashes on the screen and then it shut down and went into protect (and status flashed 8 times). I then hit the pwr button and it did the same thing, but flashed 6 times instead.
After lots of research, I opened up the front to get to the screen plate voltage level controls and tried to adjust them. What I found is that when I turn the blue knob down (to the left) it stays on longer, but the green trace lines appear, then I would turn the green down to compensate. If I turn UP the blue knob, it NEVER makes blue trace lines, but the whole screen will eventually turn blue and then go to shut down if I keep turning up. When it hits protect, I can achieve a flashing status light of 5, 6, or 8 flashes depending on the position of the voltage knobs. Whatever I do with the blue (even when all the way down) there's still blue flashes every now and then, but the higher I bring up the blue voltage, the more flashes there is on the screen. If its almost all the way down the screen will stay on (minimal flashes) and not go into protect, for at least 5 or 10 minutes. I never put signal into the box and don't have test patterns (or a remote to enter test mode yet, but my sony remote for my sony hd tube set might work? I haven't tried yet) but I looked at the menu screens, snow, and auto-convergence pattern as viewing signals (I also turned down the picture and put the brightness ~50% as recommended in the manual, before I set g2 levels). Even with the blue g2 voltage all the way down, it might hit protect when switching input sources, as it makes long bright blue flashes when switching, sometimes. The blue picture also seems to be out of focus, or has a halo around it no matter what I do. I tried adjusting the focus knob, but it only gets worse in either direction so its already set as good as it could be. I am expecting that I will need to change the coolant because of this? (confirm, please?) I am wondering if old coolant can be causing all my problems (I doubt it), or if its other electronic components to replace (resistors or convergence amp or something), or if the flashing is being caused by a crt tube going bad (I hope not!). I have not yet tested voltage on different boards / tp's, and am a little confused about how exactly to wire a g2 jig, as recommended in the manual (I already d/l the manual). One last note, is that the auto-convergence is out of line, as it does go through the motions of trying to adjust, but then after its done (it does it's thing twice) it reverts to an out-of-convergence position, rather than getting the picture lined up right; but when it's trying to adjust, it looks like it gets pretty close even though it doesn't stay close when it's done. This tv was given as a project/gift and I would love to get it up and running, but I don't have the money or want to really spend on it if it gets expensive. My backround is audio gear (mostly pro audio gear) and I have experience with a soldering iron and board level repairs (with minimal component-level troubleshooting on my part, except for cold solder joints and burnt parts or bad caps) but I can read a schematic and follow/trace a circuit and use a multimeter to test things. I'm a little weary of the hv from the flyback now that its been energized, but not afraid to de-energize it to do more repairs. Any help would be appreciated! Thank you.
edit: The number of status flashes I am working from memory, but it might not be the correct #'s. I know the status codes were for voltage or current overloads, a particular bad part# (5 flashes), or white balance off.
Topic: Sony KP-57hw40 issue (Read 5904 times)