1 2 secs screen goes dark - still sound
Hi all,
Already found a question related to mine, although I couldn't find a solution that fits my board in there.
The problem: I turn on the screen, get 2 secs of screen-time and then it goes dark. I still get sound, but no screen, only black.
I opened up the screen to take a look at the PSU as this seems to bring a lot of the problems, however I don't seem to find anything wrong with it?
Could you maybe help me figure out what is wrong with the screen? (included pictures of the PSU board)
Thanks.
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Hi, I agree with you about D109 I'm also wondering why the board under component D109 is looking like it has got very hot. If you can for a start check the solder connection of it (on the other side) and check that the diode itself is not s/c. Also check the two capacitors close by
by jayeff
I don't really know that much of electronics, but when I use a multimeter to check the connection, I get a rating.
I'm thinking of soldering D109 out and replacing it, as well as some capacitors.. however, I don't see any "malfunction" with the capacitors: no bubble on top, no fluids that came out..
What do you think?
(PS: how can I see what kind of diode the D109 is? It just says 3907 (or that's all I can see atm))
by Geforce660
Hi, If you unsolder one side of D109 off the board and then measure directly across it with an Ohmmeter, you should get a low resistance reading in one direction and a high resistance reading when you reverse the meter leads and test it again. If you get a low resistance reading in both directions , it is faulty.
It may be testing alright and is showing signs of getting hot, because something in the same circuit path as it is is faulty and there is too much current flowing through it. Not enough to completely burn it but enough to make it very hot. If this is the case it is probably being 'saved' from being destroyed completely by the protection circuits built into TVs shutting the TV down before this happens.
You may wish to measure D103 (out of circuit) as from the picture it appears (if it has the same marking) to be the same as D109 and looks OK just to compare the meter readings to see if D109 is OK
by jayeff
Hi, so I replaced the D109 diode to be sure. As well as all capacitors of 10V. Turned on the screen again, with the TV connection active.
I receive both sound and picture, but it seems the monitor does not emit any light to display the image that it receives. - in other words: all signals come into the monitor, but the lights inside the monitor do not seem to stay on (2 seconds screen and it's lights out).
Any suggestions?
by Geforce660
Hi,
The inverter board usually controls the backlighting for a TV. So you may wish to look for this board and check it for problems.
by jayeff
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