Re: Samsung 940NW - 2 seconds to black - now just black!
Budm,
Yes, a replacement transformer fixed it. Thanks you and everybody who has helped. This is the most awesome forum!
Kevin
kktlam
Member
Last Activity: 04-07-2013, 05:29 PM
Joined: 01-13-2013
Location: Vancouver, BC
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Re: Samsung 940NW - 2 seconds to black - now just black!
Thanks Budm, I'll purchase a replacement and report whether it works.Leave a comment:
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Re: Samsung 940NW - 2 seconds to black - now just black!
I checked the sockets and they looked fine. All 4 blue capacitors are the same so I swapped them around, but the situation remains: dim on CN303 and off on CN304....Leave a comment:
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Re: Samsung 940NW - 2 seconds to black - now just black!
I tried connecting each CCFL to each of the sockets, they all behave the same: CN301 and 302 seem OK, 303 very dim, 304 not on.
As a separate note: Do these sockets output a pulse of 650V or a continuous voltage? Is it safe to use a meter that can measure up to 1000V? I can borrow such a meter, so if there's something I can measure I'd like do that first tomorrow, before swapping the capacitors.Leave a comment:
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Re: Samsung 940NW - 2 seconds to black - now just black!
They are lit brightly on the other two connectors, CN301 and CN302.Leave a comment:
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Re: Samsung 940NW - 2 seconds to black - now just black!
I've reflowed all the components carefully, but still no go.
Today I tested the panel on a dimmed room, and for the first time noticed that CCFLs on CN303 and CN304 are not totally dark as I believed last time: on CN303 the light is very dimly lit, on CN304 it doesn't light up.Leave a comment:
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Re: Samsung 940NW - 2 seconds to black - now just black!
Both C313 and C314 are out of range. I'll try to touch up on all the solder joints ... the SMDs will take a while!Leave a comment:
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Re: Samsung 940NW - 2 seconds to black - now just black!
Ah, that makes sense. I hope it's not too difficult to find out what is wrong... any help is much appreciated!Leave a comment:
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Re: Samsung 940NW - 2 seconds to black - now just black!
Sorry, it got buried in post 6. [B]990 ohms[/B]. But today when I measured them they read 998 ohms - both windings the same.Re: Samsung 940NW - 2 seconds to black - now just black!
Sorry, it got buried in post 6. [B]990 ohms[/B]. But today when I measured them they read 998 ohms - both windings the same.Re: Samsung 940NW - 2 seconds to black - now just black!
Sorry, it got buried in post 6. [B]990 ohms[/B]. But today when I measured them they read 998...Leave a comment:
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Re: Samsung 940NW - 2 seconds to black - now just black!
I tried each of the 4 CCFLs on CN301 - CN304, either alone or in pairs, but they don't turn on when plugged into CN303 or CN304, but they do when plugged into 301 or 302. Hope we're onto something... though I'm pretty clueless at this point with what is causing this? I looked at the manual Sabre504 posted but I don't really understand which is which - the component numbers seem to differ from the board.Leave a comment:
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Re: Samsung 940NW - 2 seconds to black - now just black!
The recycler's junk pile yielded what I wanted for a very cheap price! So the good news is, I get video signal back. (I must've blown the clamp when juggling the circuit boards when plugged in...) The bad news is, 2 seconds to black still happens... Guys, what other diagnostics would you suggest?Leave a comment:
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Re: Samsung 940NW - 2 seconds to black - now just black!
Thanks Retiredcaps. The monitor repair is not a rush, it can wait for sure. From where I live, there is an electronics recycler nearby that lets me look through their junk pile - so I'm actually thinking of doing that first... yeah $8 shipping for a $1 order is kind of steep!
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Re: A bad and a good LED in series
You guys are good. Well, it was not a short - just a corroded trace, but indeed on the camera board. And the whole time I thought the LEDs were broken!
Lesson learned: next time, check the obvious things first...
...
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Re: Samsung 940NW - 2 seconds to black - now just black!
Hi Sabre504,
Thanks for looking these up! I wouldn't be able to find any of that (without your extensive knowledge of electronic components.)
I'll make an order and see what happens next. Thanks so much for all you guys who have helped: you of course include selldoor and especially retiredcaps!
KevinLeave a comment:
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Re: A bad and a good LED in series
...COMPLETELY EDITED...
I think I am misunderstanding what you meant by "bad or good LED series" ... would you explain to me as I'm new to electronics? The situation is that two LEDs are in series (ie. not in parallel) and one LED seems to be causing the entire circuit to turn off, but individually each one lights up.Last edited by kktlam; 02-03-2013, 11:24 PM.Leave a comment:
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Re: Samsung 940NW - 2 seconds to black - now just black!
I'm thinking of replacing this diode package. Seems hard to find - may be I'll look for it in other broken monitors. Meanwhile, is there anything I should check? I'm a little worried that something else is causing this voltage limiter to blow - I think it acts like a fuse.Leave a comment:
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A bad and a good LED in series
Hi members,
One of my hobbies is taking apart faulty digital cameras to try to understand the problems, or even fix them. I have successfully repaired a number of mechanical issues but recently I came across an electronic issue that I hope to learn something about.
A typical camera's LCD screen is illuminated by white LEDs. This particular Sony model I am looking at uses two surface mount "side view" LEDs to illuminate the edge of a clear plastic "glass", which is engraved with dots to reflect the light evenly out onto the "glass" surface.... -
Re: Samsung 940NW - 2 seconds to black - now just black!
Here we go. The first number is red probe on PIN 2/5, the other number is reverse ie black probe on PIN 2/5
PIN2/5 to PIN1 = open,open
PIN2/5 to PIN3 = 046,047
PIN2/5 to PIN4 = 068,071
PIN2/5 to PIN6 = 832,open
I was reading the the multimeter's user manual: is it correct to interpret these numbers as diode at PIN1 open, diodes at PINs 3 & 4 shorted, and only diode at PIN6 is good?Leave a comment:
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Re: Samsung 940NW - 2 seconds to black - now just black!
I'm not entirely sure which 8 readings: do you mean forward/reverse measurements at each anode/cathode pair?Leave a comment:
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Re: Samsung 940NW - 2 seconds to black - now just black!
Impressive! Thanks sabre504.Leave a comment:
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