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Any ideas on this? please.

Hi all,

I am hoping someone here may be able to help me with solving an intermittent fault with our family TV It is a Phillips 21PT2012 / 79R and has what I think is the serial number of BZ000231 723707 on the back cover. The fault manifests itself as sudden loss of all picture, and light from the screen and loss of sound at the same time, anywhere from 5 seconds to a few minutes from switch on. This started a week or so ago, and a turn off seemed to fix it, and now it will not run longer than a minute or so without dying. It seems like the HT supply drops out suddenly, but as I understand it the power supply rails for all the circuitry on this type of appliance may very well all come from one switching supply, and a fault there could wipe out everything? I have a reasonable understanding of electronics, and a good Fluke multimeter, but no cct. diagram, and no experience with TVs. Any suggestions? I think that the set is about 4 years old, and I guess it must be some component that is built to a commercial standard starting to break down, but I was hoping that there may be hope rather than junking it? Thanks for any assistance.

Tim

Reply to
Tim
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check for bad solder joints on the board. and also the circuit control voltage relay which most likely is in the power supply section, that many times burn the contacts. if not that, find the regulator on the switching supply, test for voltage getting to that point. Also, you should take note if the TV seems to have a short burst of power before it decides not to fire up, this would indicate a short maybe in the HT section. Normally the Start up circuit in the switching supply has a short override of the fault sensing from the HT section so that it makes an attempt to start.

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"I\'m never wrong, once i thought i was, but was mistaken"
Real Programmers Do things like this.
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Reply to
Jamie

The problem with getting a schematic and monitoring the voltages is...?

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Many thanks,

Don Lancaster                          voice phone: (928)428-4073
Synergetics   3860 West First Street   Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml   email: don@tinaja.com

Please visit my GURU\'s LAIR web site at http://www.tinaja.com
Reply to
Don Lancaster

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Many thanks,

Don Lancaster                          voice phone: (928)428-4073
Synergetics   3860 West First Street   Box 809 Thatcher, AZ 85552
rss: http://www.tinaja.com/whtnu.xml   email: don@tinaja.com

Please visit my GURU\'s LAIR web site at http://www.tinaja.com
Reply to
Don Lancaster

Hi,

I th> Hi all,

Reply to
bhaskar1996

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