Got a 55" LCD from a friend after suffering a lightning strike. It fried their DirectTV receiver and had a arc across the coax connection. This is actually their 2nd hit, the first set I got from them had a fried HDMI port.
On this one, I am not getting any signs of life. My mm is at work and I will be able to check voltages tomorrow.
Attached is front and back of main and power board.
The main board is out of stock just about everywhere I can find. Ebay has repair services for $125. Do not want to spend that much if I can avoid it....
Jim1590
Senior Member
Last Activity: 08-09-2023, 07:25 AM
Joined: 07-07-2013
Location: New Britain, CT
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LG 55LK520-UA Lightning strike
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Re: RCA 46LA45RQ no backlight
Not at home to test right now, but wouldn't a bad fuse be bad all the time? The backlight works for a few min and incidently it works much longer if I have the back cover off. Discovered that when I was testing. That's why I thought heat related cap issues. -
Re: RCA 46LA45RQ no backlight
Nothing on the back. Looks like there is no tracings or components at all. On the front, most of the solder points have at least some Browning.Leave a comment:
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Re: RCA 46LA45RQ no backlight
Anyone?Leave a comment:
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Re: RCA 46LA45RQ no backlight
Second set...Last edited by Jim1590; 02-04-2017, 05:00 PM.Leave a comment:
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Re: RCA 46LA45RQ no backlight
First set...Last edited by Jim1590; 02-04-2017, 04:59 PM.Leave a comment:
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RCA 46LA45RQ no backlight
Greetings all again. Craigslist freebie here. No back light after a minute or two when powered on. Flashlight test shows that the image is still on the screen.
Opened it up and got 23-24 volts on all 5 pins going from power board to the backlight inverter board. When the backlight cut out, no change in the readings.
Right now I am thinking a bad cap somewhere on the backlight board. There are 8 caps at 35v 390uf. Since the TV is 7 years old, I might as well replace all 8.
Now I have a bag of 35v 470uf caps from a prev repair. Was just as cheap to buy... -
Re: e701i-a3 no picture but backlights
I get the same picture breakdown when I am streaming something from my home server with a file coded more towards small size vs higher quality. Even on my new 55" 4k LG.
If you are in fact streaming from your computer, NAS, whatever, then put a video test pattern onto it that you can play. A picture test pattern works as well....Leave a comment:
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Re: e701i-a3 no picture but backlights
And it is DONE! Removed the left side drivers by the control buttons and have a great picture.
Swapped my repaired board for the new one I got and the tv would not display a picture. V for a few seconds then black. Repeated several times. Hmmm.... put the repaired board back in and enjoyed watching tv on it. Board going back.
This is the first time using this TV, or anything this big. Picture is not as sharp as I was expecting. Not as clear so to speak. Probably the settings or my input.
On a side note,...Leave a comment:
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Re: e701i-a3 no picture but backlights
Lower left cable is disconnected as we are looking at the TV display.
The test signal is actually a video I was running via plex that I downloaded from here:
[url]https://vimeo.com/41414940[/url]
Also concerned about the clarity of the image. I do have a new tcon that I can put in once I know I am not going to short it. Also have another main board tha tmay be working, may not.Re: e701i-a3 no picture but backligh...he TV display....Last edited by Jim1590; 02-05-2016, 07:32 PM.Leave a comment:
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Re: e701i-a3 no picture but backlights
Will do. Probably tomorrow night or the weekend.
Thanks...Leave a comment:
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Re: e701i-a3 no picture but backlights
I re-seated all of the cables and I swapped the main board with another one that came with the tv. Figured why not. The following pictures are with the left side looking at the display (right side when looking at the tcon) ribbon cable disconnected from the driver boards. I only got the menu up, I do not have any nearby sources, but if it is really needed, I can get one to the tv.
When I took these pictures, I had no problems whatsoever besides the lines. The TV stayed on and I was able to bring up the menu and...Leave a comment:
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Re: e701i-a3 no picture but backlights
A quick update on mine, as well as wanting to make sure I am on the right path.
I replaced the mosfet on one of my two tcon's. My sodering skills are not that great and it looks like a poor connection. But I have a new one coming (at least advertised as new.) I have the second board and one more mosfet. Keeping those as back ups.
I pulled the left side ribbon cable going to the drivers. Left as we are looking at the back, right side while watching. Turned the tv on and got lines along the bottom half of the screen...Leave a comment:
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Re: e701i-a3 no picture but backlights
gormanrider, what ribbon cables are you removing? For diagnosing, we are leaving the 4 ribbons into the tcon alone and unplugging the ribbon cable on the side of the tv where it is plugged into the side boards. Look at the lower corner of the tv on both sides, not the lower corner of the tcon. You have to remove a shroud to get to them.
Are you getting those pictures with a bad mosfet??Leave a comment:
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Re: e701i-a3 no picture but backlights
Don't think the blue screen is this issue. The issue here is black screen with no video input.
Try it with an input and double check all wires are seated properly.
Course I am guessing here. The experts will be by hopefully soon.Leave a comment:
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Re: e701i-a3 no picture but backlights
Ohh, ohh! My turn!
Got the vizio 70 inch on craiglist for $100. Guy already got a replacement t-con and main board. Said he opened the back and got scared, decided to sell instead. He powered it up for me and only got a backlight.
I opened it up and the t-con was disconected at all 4 ribons. Pulled the t-con and grabbed his replacement. 000 and 000 readings on the mosfet for both boards. So he either replaced the board and shorted, or the new one is bad.
Anyone have a link to buy the ones referenced above?...Leave a comment:
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Re: Hannspree HF257 w/bad backlight
bluesj,
You did seem to drag up an old post but I can say that yes, replacing the power board may help you.
I had the same issue on my Hannspree that I liberated from the town dump with the 2 seconds to black. I could not find any bad caps and the problem seems to be with the back lights. The back light board is built into the power board.
Fret not, I got myself a board shipped from China for $25. Put it in and am using it now. Has been running for 3 hours straight.
[url]http://www.boardss.com/index.php?main_page=product_info&cPath=10&products_id=1150[/url]...Last edited by Jim1590; 10-21-2015, 07:19 PM.Leave a comment:
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Re: Hannspree hf257hpb
Seems my links did not work...Leave a comment:
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Hannspree hf257hpb
Rescues from the town dump. Some slight scratches on the screen but barely there.
Plugged it in and got a faint red tint that went away over about 5 seconds. Monitor would then turn off after anywhere from 10 to 30 seconds. Repeated several times.
No obvious bad caps. Here is the power board. Thanks in advance... -
Re: Toshiba 37RV530U No power
Sorry to revive the older thread but have some updates.
Got a power board on eBay, appears to work fine.
Replaced backlight board, screen lights up.
Now, no picture. I have volume when I hooked a audio cable up off a Xbox. Volume went up and down. Changing inputs seemed to have worked as well. Just no video.
Tcon, or main board? Luckily those are to be found on eBay.
Thanks!Leave a comment:
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