Re: Olevia 747-b11 power on, screen dark
I found only two 3-pin regulators, they are shown with white arrows on one of the attached photos. By the way, when the unit was ON, there were 8 green and 2 red lights on; when OFF, one red light. Does it mean anything in terms of what's working and what's broken?
Both regulators are marked "1084-33 0707HL". I measured voltage between pins of both regulators in both OFF and ON. Here's what I got:
ON:
- top reg
Vin-GND 5v
Vin-Vout 1.69v
Vout-Gnd 3.3v
...
ilyaz
Member
Last Activity: 12-20-2013, 09:03 PM
Joined: 11-29-2013
Location: Rockville, MD
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Re: Olevia 747-b11 power on, screen dark
Ok, will do, but if any of them, or any other parts of the main board, are bad, can they be replaced, or will I need to replace the whole board? Found a few more links to the board online (besides yours above) and they all say "out of stock". Thx...Leave a comment:
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Re: Olevia 747-b11 power on, screen dark
What Blue/Yellow voltage is normal for OFF and ON?...Leave a comment:
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Re: Olevia 747-b11 power on, screen dark
The two side boards are connected with the black/red/blue/yellow wires. I don't see any cables/connectors that are obviously disconnected.
By "main board" do you mean the power board in the middle?
Yes...Leave a comment:
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Re: Olevia 747-b11 power on, screen dark
OFF: Blue 51.4 mV, Yellow 51.3 mV
ON: Blue 37.0 mV, Yellow 48.6 mV...Leave a comment:
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Re: Olevia 747-b11 power on, screen dark
Between yellow and blue:
TV OFF: 0
ON: 11.6 mV...Leave a comment:
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Re: Olevia 747-b11 power on, screen dark
OK, put the screws back in. Now want to make sure I am measuring right.
I plugged in the TV but did not turn it on. Is that the 1st measurement? Do I measure between the blue and the yellow, or between the blue and GND and the yellow and GND?
And then for the 2nd measurement, do I repeat the same with the TV turned on?
BTW, my multimeter is fairly old and what I noticed when I measure is that the reading jumps around. I tested it by measuring an AAA battery and it shows the right...Leave a comment:
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Re: Olevia 747-b11 power on, screen dark
Right board conn labels:
Red X 5 = VBL
Black X 5 = GND
no wire X 2 = NC
Left board:
Red X 5 = VBL
Black X 5 = GND
Black = VSEL
No wire = E_PWM
Yellow = I_PWM
Blue = BLON
I am having trouble uploading additional photos (maybe uploaded too many already). On previous ones, can you tell me where the fuses are? And do I do a connectivity test on them with a multimeter? Thx...Leave a comment:
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Re: Olevia 747-b11 power on, screen dark
quote from earlier in the thread:
So whether or not this has done any additional damage, I am still trying to figure out what the original problem was....Leave a comment:
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Re: Olevia 747-b11 power on, screen dark
OK, finally moved the piece and removed the covers from the side boards.
Photos:
- right board
- left board
- zoom in on right board of one of 4 seemingly identical blocks
- zoom in on the middle part of right board
- markings on the right board (I guess the left board is the same)
I am not seeing anything that looks obviously damaged or burned. What should I check next? Thx...Leave a comment:
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Re: Olevia 747-b11 power on, screen dark
Will do, as soon as I move the thing to where I can lay it flat...Leave a comment:
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Re: Olevia 747-b11 power on, screen dark
I am wondering if the fact that I am getting 24v to the side boards means that the power board is fine....Leave a comment:
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Re: Olevia 747-b11 power on, screen dark
Budm, where are those fuses on the photo? Are they the two white ones marked KOAC? Which one of the black parts is the fuse? Thx!...Leave a comment:
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Re: Olevia 747-b11 power on, screen dark
OK looks like it's 24v on both sidesLeave a comment:
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Re: Olevia 747-b11 power on, screen dark
But what did I do wrong when I tried to measure while connected? I thought I was supposed to touch one of the pins next to the red top and one of the pins next to the black bottom of the connector with probes of my voltmeter. Or do you think I accidentally touched the metal cover on the right side of the photo with the side of one of the probes?Leave a comment:
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Re: Olevia 747-b11 power on, screen dark
OK, this did not go so well. I realized that last time I measured, I did not turn the TV on. Turned it on and tried to measure on the right board. Got a spark and now have a black spot on the pins (see photo). Does it mean this board is likely fried and I will need a new one?
After that disconnected and measured as I did the 1st time. Got a reading of about 36v on the right but only about 1.1v on the left....Leave a comment:
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Re: Olevia 747-b11 power on, screen dark
It was a bit hard to get the voltmeter probes to touch the contacts, but I think I did it, and I got 0 on both sides....Leave a comment:
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Re: Olevia 747-b11 power on, screen dark
OK here's what I have now: a photo of the whole back, then the power board in the middle, showing a couple of caps that seem to be OK, then the left and right boards. I have not removed the covers from those yet since I need to first find someone to help me move the TV somewhere where I can lay it flat. Once I do that I can remove the covers and take more detailed photos. Thx...Leave a comment:
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Olevia 747-b11 power on, screen dark
I will attempt my first ever LCD TV repair. Wish me luck.
Picked up an Olevia 747-b11 LCD TV. When plugged it, I can see the blue power light in front and some green lights through holes in the back cover. Screen is dark.
I took off the back cover. The caps on the power board seem to be OK. At least those that I can see without taking anything else off.
There are two boards symmetrically on the right and left of the power board. I have not removed their steel covers yet, planning to do so. Is it likely that the problem is with bad caps on one of... -
Re: New Members - please post your introductions here
Hello everyone.
Was given a large LCD TV. Only a few years old, looks to be in good shape, but is not working. So want to try to fix it. Will be the first one for me of this type. Fixed things around the house on a regular basis, but have not tried electronics yet. Should be fun! Hoping to learn from experts on this forum. Thanks.Leave a comment:
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