I have a Hitachi TV here that displays the Hitachi logo on the display when powered on (crystal clear. no problems) for about 8 seconds then the display goes black.
You can hear the clicking from menu interaction after it goes black but can't see anything. The backlights stay on the whole time. Since the replacement boards are fairly cheap I went ahead and ordered refurb power supply and mainboards. I installed them but the problem persists.
I figured a problem with the LED driver board was unlikely since the LED backlights aren't shutting down. And the T-Con I would...
AmpWare
Member
Last Activity: 10-19-2018, 09:56 AM
Joined: 01-14-2014
Location: Uniontown, PA
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Hitachi 65R8 Black screen
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Re: LG 55LA6200 (Bad Mainboard)
Good News. The 55LA6205 mainboard came in and all is working just fine. Tested all inputs and streaming over ethernet and wifi.
I'll probably still order the LGE2122 processor from china and replace the bad one to have a usable spare mainboard.
Thanks for the help
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Re: LG 55LA6200 (Bad Mainboard)
I found this board for LG model 55LA6205-UA
[URL="https://www.shopjimmy.com/lg-ebt62368572-main-board-for-55la6205-ua.htm"]https://www.shopjimmy.com/lg-ebt62368572-main-board-for-55la6205-ua.htm[/URL]
The feature set is near identical except the 55LA6205 lists
120hz true motion
MCI 240
55LA6200 has the same 120hz true motion but no MCI 240 mentioned.
According to SJ both have the same LCD panel sticker number LA62M55T120V12
Update: I just went ahead and...Last edited by AmpWare; 11-04-2016, 02:22 PM.Leave a comment:
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Re: LG 55LA6200 (Bad Mainboard)
The main board is marked 55LA6200-UA BUSULJR
Thanks for the help btw...
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Re: LG 55LA6200 (Bad Mainboard)
Thanks for looking
That board is for model LG 47LA6600 though. While the boards are probably electrically the same the firmware is different and may have a different feature set.
By a quick glance at the spec sheet it seems like the fundamentals are covered. 120hz, 3d, same smart TV features..
Anyone else have any feedback or know of potential problems the 47" model board would cause outside of just the oddity of the model being wrong in the menus.
I also found this one shortly after posting....Last edited by AmpWare; 11-04-2016, 09:36 AM.Leave a comment:
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LG 55LA6200 (Bad Mainboard)
I obtained an LG 55LA6200 that was about to go to the landfill. Figured I would attempt to rescue it
The problem with the set is that when powered on the red standby light flashes a couple times then goes off. The power supply remains on. 3.5v, 24v and 12v feeds are all good, 84v to the LED strips but from what I understand that's pretty typical when they are off for this set.
The original owner said that during an electrical storm 2 of the HDMI ports stopped working (1 and 2) but the set functioned ok on HDMI 3 for a while after then stopped turning on so I figured... -
Re: Vizio e601i-a3 stuck on logo
I use Kingbo RMA-218. Flows pretty nice at soldering temps and does a decent job cleaning the contacts and rejuvenating the solder. For the original silver based solder I ramp up temps to 190c slowly over a 5 minute period then for the last 45 seconds I bring it up to 230c.
It's important to preheat the mainboard to at least 120c to prevent excess warping under the BGA. I also usually put a couple pennies on something the size of that mediatek processor to make sure the balls reseat and the chip doesn't try to float on the flux.
...Last edited by AmpWare; 03-21-2016, 02:01 AM.Leave a comment:
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Re: Vizio e601i-a3 stuck on logo
Wasn't a corrupt flash after all. Reflowed the mediatek processor and it fired right up.
...Leave a comment:
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Re: Vizio e601i-a3 stuck on logo
LoL. Sorry brain fart. I was looking at another set and for some reason the model # stuck when I was looking up info. The set I have working on is actually a E600i-B3 and it looks like the firmware is stored on a sandisk BGA chip. I do not have the ability to program that unfortunately.Leave a comment:
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Vizio e601i-a3 stuck on logo
As the thread title says I have a E601i-A3 that turns on and lights up but gets stuck on the "V" logo. Tried the 30 second power hold while off then leave unplugged for 10 min and still the same. I suspect a corrupted EEPROM. I have the equip to flash the chip but I haven't had any luck finding the firmware itself.
Anyone by chance have a firmware dump from that set or a compatible set?
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Re: e701i-a3 no picture but backlights
Thanks to the brave freakafr8 who yanked off his gate driver tabs I now have a fully usable Vizio VL470M. It uses a LC470WUH (SB)(R1) panel made by LG. i had a similar problem with it where the top left driver died a horrible death. I looked for weeks for a smashed panel with the same type of driver to use to repair this panel to no avail.
After stumbling across this thread I figured I might as well.. so I peeled the remaining tabs down the left side of the panel and what do you know.. it worked!
So now we know...Leave a comment:
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Re: In search of Gate driver flex tab
First I apologize for the shameless bump
I haven't had any luck thus far locating a shattered panel or somebody with one willing to sell me a couple gate driver tabs. I figured since i was bumping I'd toss in a few of the shots I took with my microscope to show a bit more about how the ACF tape works to connect these flex cables and for scale.
The above image is of the edge of a iphone 5s lcd with the flex cable removed. you can see the area where the ACF was applied outside of the flex cable...Last edited by AmpWare; 03-08-2016, 05:25 PM.Leave a comment:
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Re: In search of Gate driver flex tab
[URL="http://www.aliexpress.com/item/AC-7106U-25-ACF-Film-adhesive-W1-5mm-L50m-ACF-conductive-film-adhesive-Anisotropic-conductive-adhesive/32409030355.html?spm=2114.40010208.4.9.2OxzfK"]aliexpress link[/URL]
Is this what you found? Pretty decent find. Looks to have roughly the same specifications as the 3M tape and less than half the price.
Below is the datasheet for it.
[URL="http://www.eevblog.com/forum/chat/diy-hotbar-bonding-machine/?action=dlattach;attach=109464"]ACF...Leave a comment:
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Re: In search of Gate driver flex tab
The bonding tape the LCD assemblers use is Anisotropic Conductive Film (ACF) or also sometimes called Z-axis tape. It contains microscopic conductive particles that smash between the contacts when heat and pressure is applied to bond and cure the adhesive.
The glue they use to bond the glass/digitizer and LCD together on cell phones is Liquid optically clear adhesive (LOCA) and electrically insulative. it won't work for tab bonding unfortunately
would be nice since it's so cheap
[URL="http://multimedia.3m.com/mws/media/919128O/3mtm-anisotropic-conductive-film-7379.pdf"]3M...Last edited by AmpWare; 02-22-2016, 04:34 PM.Leave a comment:
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Re: In search of Gate driver flex tab
The source drivers (the ones across the top of the LCD) run around 150F roughly. The gate drivers run much cooler. around 95F on this panel at least.
I'm not 100% sure but I believe it's because the source drivers are controlling more of an analog signal and generating some internal heat via a resistive ladder where the gate drivers are probably just fully swinging the voltage to rail full on or off for the current line and offering a very low on resistance and in turn low heat output on the die.
Of course...Leave a comment:
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Re: In search of Gate driver flex tab
As a quick update. I started thinking that although it might be pretty uncommon perhaps the ACF itself was causing a short somewhere. Not too familiar with the failure rates in regards to that but I imagine with the very fine space between the traces it was at least possible.
Since I had already used acetone to dissolve the old ACF I figured why not line up the flex tab I removed and see what happens when I press it into place.
I lined up the fiducial marks and secured it with a strip of kapton tape then used a bit...Leave a comment:
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Re: In search of Gate driver flex tab
I've done SMT soldering with pin pitches comparable to the fingers on the pcb side of those flex cables. pretty easy to line up even with the naked eye... he may have been shifted one to the right or left when he bonded it?
The contacts on the glass are far finer. hard to make out with the naked eye with any distance so I'll def need to make a jig with a threaded fine adjust and use a magnifying glass at the least....Leave a comment:
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Re: In search of Gate driver flex tab
Sure if I can locate a suitable replacement flex tab...Leave a comment:
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Re: In search of Gate driver flex tab
If the pitch for the conductive strips were fine enough I don't see why it wouldn't work technically but it would probably be quite a bit more fiddly than just heat bonding using ACF...Leave a comment:
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Re: In search of Gate driver flex tab
I enjoy a good challenge...
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