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Samsung LE32R87BDX Power cycling

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Davy:
Hi zomlkula, sorry for the late reply. I tried your advice and still the same I'm afraid, the two SMD 1000u, 10v types.

I was advised to try IC1804 on the main board as it causes the problem described. I was told this AFTER 'having a toot' under the screening can and had already put it back - so looks like it's going have to wait a day or two until I get my new gardening tool..... 'aroundtoit'  Must say thing's looked pretty much cooked under there, the plate is also used as a heat sink on two chips coupled by two  large blocks of what looks like spongy foam with oily stuff between it and the chips - not greasy as I would have expected, the blocks are pushed firmly against the chips.  Seen some heat sinks in my time but not foam or whatever it is, oxide coated maybe.

I'll report back should I manage to fix it, Dave.

Davy:
Replacing the Eprom IC1803 did help with the power cycling.  The Eprom can be reset by switching the set off, shorting pins 5 & 6 with longish leads, switching ON then undo the short, in my case this trick didn't work.

I reduced the power cycling, the set would then switch OFF and ON (it wouldn't before), the picture was all lines, on-screen display box full of lines popping up by itself & no sound.... I scrapped it.

The main board was singled out as the problem - I did keep the good parts. After all, the CPU appear to run 'unusually warm' for my liking.

zomikula suggested earlier I changed the two SMD 1000uF caps. outside the screening can.... I changed them and two more that was inside to be sure.

Thank you everybody for helping,  Dave

imran khan:
http://electronics-tricks.blogspot.com/
For repair help topics

downunder:

Hi Dave,
Thanks for reporting the outcome. Sometimes, you just gotta let go.

Bruce

Davy:
The Tcon connector lead or Tcon board CAN result in power cycling like this with Samsung tellies.... but not in my case.

Sure had me beat, the psu voltages were within spec and hash free, all the main board regulators were up and running - except no back-light ON control.... they worked OK when 'forced' ON, I even tried a new Eprom, the CPU was running much warmer than normal I would say.

Still puzzled why the screen would come up when I disconnected the speakers, the power cycling still continued though but not as bad.... it wasn't the audio chip either?

Dave

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