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KP53XBR45 advanced troubleshooting syscon

Discussion in 'Electronic Repair' started by JURB6006, Apr 28, 2004.

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  1. JURB6006

    JURB6006 Guest

    You're gonna love this one;

    I'm working on this 53XBR45 without a print. I'm not that unfamiliar with this
    type of unit, so I didn't scream "print, bloody print" when I saw a pretty
    strange symptom.

    Every second, or a bit over, for about 1/10th of a second the geometry would
    change. In the "normal" state, the side pin is off, but this is right for about
    100mSec every second.

    I looked around in there and I find a board with a micro, the jungle IC, and an
    EPROM on the back.

    After fiddling around in the menus (at first just the customer ones) I found
    that changing the color setting might make the set go green, that is shutoff
    red & blue, not slick green. Other abberations exist when I get into the
    service menu. None of the values "look" corrupt, changing them frequently has
    the wrong effect, or no effect, or an effect until the thing cycles again.
    Changing certain things changes the effect when it cycles, but it always cycles
    at the same rate.

    Now I got a micro, jungle and an EPROM on the same board, so I decide to take a
    shot at the EPROM. Sony EPROMs are not known to be a big problem, at least to
    me, but I know the higher failure rate of them versus other chips, except for
    power devices. Reasonable, order the part, especially since it's not expensive.

    I change it expecting one result, but what I got was the same cycling, but now
    what it does is flash green. Not slick green, but as if the drive was say
    tripled during the short part of the cycle. Let me add this, the picture
    appears as though the picture and sharpness are turned all the way down, but
    the OSD dosn't confirm this. This was true before as well, it did not change in
    that respect. The new chip of course isn't set to the set, and now, why bother
    ? I did save the old one :)

    Now I am a bit fuzzy on the data structure and the architchture of this set,
    but it wasn't built on Mars. After talking to Sony tech ($$) they said a
    different IC (EPROM) than that which I had changed. I changed IC3002, the EPROM
    they want me to change is over in the assembly with the tuners and PIP circuit.

    Now after a bit of thought I wonder if we're BOTH WRONG.

    Well known fact: these EPROMS and all the chips that run off them are serial
    data. different data are seperated by timing. These chips are externally
    clocked. They are clocked by the micro right ? as is everything else ? (not
    certain parts, especially of the jungle IC)

    While all the other chips might actually generate data, they don't generate the
    timing (CLK) right. Only one chip times the system, everything else just reads
    that. I know that's not true of an RCA DTV series, but it should be true of
    this set. Although now I may have to regroup, you see, the data are not
    changing, the abberation is only affecting reads, obviously, so either we have
    a read that is being obliterated by something else on data & clk. It has to be
    a chip out of sync. It has to be because it corrects itself, but the it's
    screwed up again for 9/10th of a second. How come those EPROM values aren't
    changing, and by now would've changed possibly to values that would not allow
    the set to run.

    Here's the kicker: When I changed that EPROM, the set remember it's channels
    and all settings (or so it thinks), it was still programmed. This leads me to
    believe the other EPROM is OK. It has to be an IC that can output data, some
    don't. It has to be something with it's own clock, and THAT is what's out of
    sync. Of course an EPROM does put out dat . . . . .It could be, I will change
    it.

    If anyone ( I am at a loss for words ), thanks in advance.

    JURB
     
  2. Jerry G.

    Jerry G. Guest

    Before you changed the EPROM, did you take a scope and check the drive
    pulses in the pin amp to see where the change is coming from. It would be
    best to get the service manual (available from Sony), and use a scope to go
    through the related circuits.

    There are a lot of complicated set-ups in these EPROM's in dealing with the
    internal set-up of these sets. Not very many shops are even equipped to do
    the proper factory alignment in these. I would put back the old EPROM (if it
    still has its original set-up), and properly troubleshoot the set.

    In all the years that I have been working on Sony sets, I very rarely had an
    EPROM or uPC problem. Most of the failures in these sets were from caps
    wearing out, cold solder connections, failed tuner and or IF modules, and or
    a combination of small parts, and power type semiconductors that have
    failed.

    --

    Greetings,

    Jerry Greenberg GLG Technologies GLG
    =========================================
    WebPage http://www.zoom-one.com
    Electronics http://www.zoom-one.com/electron.htm
    =========================================


    You're gonna love this one;

    I'm working on this 53XBR45 without a print. I'm not that unfamiliar with
    this
    type of unit, so I didn't scream "print, bloody print" when I saw a pretty
    strange symptom.

    Every second, or a bit over, for about 1/10th of a second the geometry would
    change. In the "normal" state, the side pin is off, but this is right for
    about
    100mSec every second.

    I looked around in there and I find a board with a micro, the jungle IC, and
    an
    EPROM on the back.

    After fiddling around in the menus (at first just the customer ones) I found
    that changing the color setting might make the set go green, that is shutoff
    red & blue, not slick green. Other abberations exist when I get into the
    service menu. None of the values "look" corrupt, changing them frequently
    has
    the wrong effect, or no effect, or an effect until the thing cycles again.
    Changing certain things changes the effect when it cycles, but it always
    cycles
    at the same rate.

    Now I got a micro, jungle and an EPROM on the same board, so I decide to
    take a
    shot at the EPROM. Sony EPROMs are not known to be a big problem, at least
    to
    me, but I know the higher failure rate of them versus other chips, except
    for
    power devices. Reasonable, order the part, especially since it's not
    expensive.

    I change it expecting one result, but what I got was the same cycling, but
    now
    what it does is flash green. Not slick green, but as if the drive was say
    tripled during the short part of the cycle. Let me add this, the picture
    appears as though the picture and sharpness are turned all the way down, but
    the OSD dosn't confirm this. This was true before as well, it did not change
    in
    that respect. The new chip of course isn't set to the set, and now, why
    bother
    ? I did save the old one :)

    Now I am a bit fuzzy on the data structure and the architchture of this set,
    but it wasn't built on Mars. After talking to Sony tech ($$) they said a
    different IC (EPROM) than that which I had changed. I changed IC3002, the
    EPROM
    they want me to change is over in the assembly with the tuners and PIP
    circuit.

    Now after a bit of thought I wonder if we're BOTH WRONG.

    Well known fact: these EPROMS and all the chips that run off them are serial
    data. different data are seperated by timing. These chips are externally
    clocked. They are clocked by the micro right ? as is everything else ? (not
    certain parts, especially of the jungle IC)

    While all the other chips might actually generate data, they don't generate
    the
    timing (CLK) right. Only one chip times the system, everything else just
    reads
    that. I know that's not true of an RCA DTV series, but it should be true of
    this set. Although now I may have to regroup, you see, the data are not
    changing, the abberation is only affecting reads, obviously, so either we
    have
    a read that is being obliterated by something else on data & clk. It has to
    be
    a chip out of sync. It has to be because it corrects itself, but the it's
    screwed up again for 9/10th of a second. How come those EPROM values aren't
    changing, and by now would've changed possibly to values that would not
    allow
    the set to run.

    Here's the kicker: When I changed that EPROM, the set remember it's channels
    and all settings (or so it thinks), it was still programmed. This leads me
    to
    believe the other EPROM is OK. It has to be an IC that can output data, some
    don't. It has to be something with it's own clock, and THAT is what's out of
    sync. Of course an EPROM does put out dat . . . . .It could be, I will
    change
    it.

    If anyone ( I am at a loss for words ), thanks in advance.

    JURB
     
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