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Thread: Sony PVM wavy edges

  1. #26
    Edo Express Delivery Guy
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    I may have "fixed" this issue.

    I had pretty much given up on this one and bought a 14M2U off eBay as a replacement. That one turned out to be junk. I opened it up and found the 14M2U has the same power supply (G board) as the 20M2U. I swapped the power board into my 20M2U and still had the waving issue, but at least this eliminated the power board as the source. I started looking into the IC's as James had suggested. The 2 PVM models share nearly all the same IC's on the main board.

    I found IC507 (uPC1377C - SYNCHRONIZATION SIGNAL PROCESSOR) looking through the service manual and thought it might be a possible source. I desoldered IC507 from both boards, installed sockets, and swapped chips. I managed to rip 2 traces running under the chip since it is in a really tight spot and spent quite a bit of time figuring out where they went to install jumpers. I fired up the PVM and had a stable picture, left it on for an hour and still no waving. I did lose all my settings for some reason.

    Now here's the strange part, when I power it up I get the same waving immediately for about 30 seconds then it stabilizes and runs perfectly fine. This didn't happen the first couple times I power it up after swapping chips. The service manual states that when this chip is replaced you should check b+ maximum and confirm hold down circuit so it is possible that adjustments are needed (section 4), but I can't make any sense of it.

    I'm going to say this one is fixed for now.






  2. #27
    JammaNationX
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    Good to hear. If it's waving still could be some other part that is failing as well.

  3. #28
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    I'm about ready to toss this thing out a window. It seemed good for a while but I'm pretty much back to a constant wobbling picture.

    The XRGB Mini is looking so tempting right now. I can't bring myself to put more time into this thing.

  4. #29
    JammaNationX
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    You might need to really inspect that board for any damage, check the diodes as well, even if they didn't blow, if the marking on the resistors aka the paint came off then that means it got pretty got but just not hot enough to pop. Diode arrays in Sony will usually have a bar on them that might say "River" which is showing what direction the power is flowing.

  5. #30
    Windjammers Wonder
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    Quote Originally Posted by Jeffpin View Post
    The XRGB Mini is looking so tempting right now.
    I'm right there with you, I had an xrgb 3 a few months ago that I used for about a month, the picture was just amazing.

  6. #31
    Mature's Love Slave
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    Get da WEGA.

    It'll cost you 50 max.

  7. #32
    Formerly Raz_Hoe.
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    Quote Originally Posted by 2D_Master View Post
    Get da WEGA.

    It'll cost you 50 max.
    Lol. Its funny you mention this. I hooked up my wega back at my parents house to play some neo through the scart to component converter and I kind of missed it. The colors are off but for the size and how cheap you could get them now they are probably the best bet. Some people give them away for free on craigslist.

  8. #33
    Raiden's Valet
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    I have had a PM do something similar when the switch for overscan mode was dirty, and it was sort of "between", changing the horizontal deflection width seemingly randomly. On that PVM, it is a discrete switch, but on the 20M2U it is controlled by software (though activated with front-facing buttons). Try pressing the underscan and overscan buttons on the front face near the left and see if that influences it.

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