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35 lines
2.4 KiB
35 lines
2.4 KiB
\documentclass[11pt]{article}
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%Gummi|065|=)
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\usepackage{graphicx}
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\usepackage{caption}
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\title{\textbf{Sony PVM 14M4U Repair}}
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\author{Steak Electronics}
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\date{}
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\begin{document}
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\maketitle
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\includegraphics[scale=0.3]{../pics/DSCN1101.JPG}
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\captionof{figure}{Barely User Service-able!}
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\section{Start}
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Video 1105.webm shows the problem. Lines moving both vertically (obvious) and horizontally (less obvious, looks diagnolly).
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The second problem, which was more of a problem at the start, was disassembly, and then putting it in a way that it could be repaired. Video from botnet Sony PVM-8041Q Monitor Teardown and Repair-iyJDam0blYA) Shows a repair of a smaller 10 inch model, and you can see, the user is able to easily access parts of the board to repair. However, the 14 inch models are not nearly as simple to access. The board with all the processing on it (the A board), is on the bottom of the chassis, and to take that out... well video 1104.webm shows what I had to do to get access to the board, while it's powered on.
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\section{Repair}
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At first I suspected capacitors had gone bad - due to the failure mode. When it originally failed, it had been working, then suddenly failed. I used an ESR meter but was unable to find any bad caps. This ESR meter is untested, so it's either that there are no bad caps, the bad caps have failed in a way besides high ESR, or that the esr meter doesn't actually work.
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I poked around a bit, but after a few minutes, remembered that voltages should always be checked somewhere early in the repair. Lucky for me, a -15v voltage is showing -25 volts. It being a negative voltage (in my limited knowledge) points to it being for an op amp, and op amps that don't have the right voltage might fail the H and V sync. I will try to fix that and hope there is no other damage.
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\includegraphics[scale=0.3]{../pics/DSCN1106.JPG}
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\captionof{figure}{The Rail is listed as -15V...}
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\includegraphics[scale=0.3]{../pics/DSCN1107.JPG}
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\captionof{figure}{Fault!}
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\section{CAUTION}
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The tube is extremely damgerous, and I get nervous anytime I go near it. Do NOT try this if you aren't careful. There is also 600V rails on the bottom of board A where the hi voltage (read flyback) transformer is. The only thing in our favor, is that there IS a service manual with some explanations of where everything is. The problem, as I already mentioned, is that actually servicing this device is near impossible.
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\end{document}
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