Re: Asus FX705H DANJJMB1AA0 boardview
I would like to 2nd this as well, I have a system with a bad backlight circuit, and I'd prefer to trace it with schematics/boardview rather than guess my way through a similar backlight circuit
Thanks!
lv128
PCB Tech
Last Activity: 07-25-2023, 11:33 AM
Joined: 08-05-2011
Location: PA
-
-
Re: Hisense f42k20egb double picture
There was actually a syrupy substance near the bottom edge, but no telling if it was before or after it was trashed. I did press on them, etc to see if it was loose at all, but I guess a short from liquid is just as likely. I'm probably just going to part it out. Shame too, I could have used a 42" tv. Thanks for the input though.Leave a comment:
-
Re: Hisense f42k20egb double picture
All of the original components were inside when I got it, warranty seal still intact, so they are native components, and unless the tcon is only "slightly" bad, since it has two ribbon interfaces to the panel and I can disconnect either one or both, and the corresponding portion of the screen goes black, but maintains the double image on the other half, I'm likely to conclude the panel as well unless anyone else has seen this with these rebadged brands.Leave a comment:
-
Re: Hisense f42k20egb double picture
Yes, with either side of the tcon pulled out, I get exactly one half of the picture, corruption/double image included. One of the reasons I wasn't sure it was tcon.
As far as eeprom, I can't seem to replace the mainboard without ending up with the buzzing/strobing backlight (it does not boot up or display picture beyond that strobing)...Leave a comment:
-
Re: Hisense f42k20egb double picture
I have a video of the bootup of the panel: [URL="https://onedrive.live.com/embed?cid=8011233CF344D1B2&resid=8011233CF344D1B2%21318199&authkey=ALdEyLzb-8NteM0"]here[/URL], there's some annoying mic whine problem in the beginning, so turn your speakers down.Re: Hisense f42k20egb double picture
I have a video of the bootup of the panel: [URL="https://onedrive.live.com/embed?cid=8011233CF344D1B2&resid=8011233CF344D1B2%21318199&authkey=ALdEyLzb-8NteM0"]here[/URL], there's some annoying mic whine problemLast edited by lv128; 10-12-2015, 07:46 PM.Leave a comment:
-
Hisense f42k20egb double picture
Since I can't seem to find anything about this particular problem, and I personally have never seen such a weird combined picture issue, I need some help.
It's a hisense trash find
Panel looks good, power is good, responds to remote and displays/processes video from all ports. Here's the picture though in attachement 1.
We've got double vertical picture and a semi-light swatch in between.
Parts attempted: Everything except the panel or the tcon or power (Yes, I know I should have tried the tcon first, but I'll get to that in a minute)... -
Re: Rii Mini Keyboard/Touchpad
Unfortunately, no, I've had the unit completely dismantled and what appeared to be a USB header is a power header, but the +D and -D don't go anywhere, so it doesn't negotiate with a usb host at all, but it does power the unit.
Not a stuck key, so I'm going to assume that this is static damage, because I had the thing face down on my couch on top of a blanket for about 5 minutes or so while moving around the living room. I've honestly never seen any electronic component die from static first-hand (heard about plenty) but given...Leave a comment:
-
Re: Rii Mini Keyboard/Touchpad
Thanks for the suggestion, but I already tried that after checking the 1/2 page pamphlet that came with the unit. the ESC key has the RF subitem (which is triggered with FN key) but just for kicks I tried F1 as in that manual you listed, but it's a no-go.
I'm pretty sure it's an electrical problem, the orange light immediately turns on and solid, indicating data, but the power light never comes on, I would assume if anything, the green power light should be on long before it tried to initialize the wireless.
Any...Leave a comment:
-
Rii Mini Keyboard/Touchpad
This isn't the best topic to post it in, but it's the closest.
I've got a Rii keyboard/touchpad, some of you might be familiar with these, they're poorly made keyboard and touchpad combos that are designed mostly for home theater PCs and cost about $60 usually.
I had it for a little over a week and it worked well, then I set it upon the couch face down and picked it up about 5 minutes later, the orange (trasmitting) light was solid, when normally only blinks to indicate transmitting, and the green power LED was off. I've tried all the normal bevvy of troubleshooting,... -
Re: Acer 5534 No Backlight (LED)
Thanks Bill, I've already look through that though, unfortunately, I'm in need of schematics instead of "replace motherboard" I've just moved on and turned the system into a headless unit for media center use, no sense in beating my head against a wall. Maybe if I encounter another one that I'm successful with I can revisit this one for a solution.
Thanks!Leave a comment:
-
Re: Acer 5534 No Backlight (LED)
I'm stumped then, any other ideas of where to look, or how to power this backlight? even if the LCD backlight is on permanently whenever the computer is turned on?Leave a comment:
-
Re: Acer 5534 No Backlight (LED)
The transistor is marked as ADXV and then 86. The 86 is printed sideways.
I did a little poking around but was unable to find any good resources for matching the part number.Leave a comment:
-
Re: Acer 5534 No Backlight (LED)
With pin one being the lone pin on it's side (and also the common I believe) and the other ones flanking left and right on the other side, my results are:
1-2 - open, 2-3 open, but 1-3 starts at 170 ohm and slowly increases to open. is this a sign of a broken transistor?
As for the diode test, all of those combinations give me open circuit except for 3-2 which the dmm shows as a 3 digit number, millivolts I'm assuming starting at 480 then dropping and stabilizing around 365.
So if only one of them reports voltage, can I assume...Leave a comment:
-
Re: Scavenge LED strips from laptop (Backlight Repair)
So far as I can tell, there's no other components on the LED strip... I destroyed about 5 of them while I was testing. some of them have groups that reverse polarity and then I ended up blowing a bunch of them,
I wish it was possible to figure out which is which before applying power, but the boards are coated with a heavy epoxy that hides the trace lines on some of them and even a scratch brush takes too long to remove them.
It's probably not worth my time to try to use their circuit board, so I'll probably just...Leave a comment:
-
Re: Acer 5534 No Backlight (LED)
So would the transistor be the most likely fault? If so, is there a way to test in-circuit without removing it?Leave a comment:
-
Re: Scavenge LED strips from laptop (Backlight Repair)
Figured out the layout for that strip, it seems some strips go in banks and some go in alternating, the banked ones are the easiest to work with, also figured out 36v @ 100ma is about their max brightness. Strangely enough going with 18v @ higher current didn't work, although I'm a bit of a noob at electrical theory, this was the voltage amount that was being sent by the controller board that I probed but it wasn't sufficient to light a full bank of LEDs, let alone the whole strip.
The higher the voltage the brighter they...Leave a comment:
-
Re: Acer 5534 No Backlight (LED)
I've got a fair grasp on electronics basics, but tbh, I'm better handling larger components than SMT stuff.
Ah, I think I understand why I can't find the ground then. Although unless the transistor is embedded into the LED, I'm not seeing any component.
Although, back on topic for this particular problem even though this may explain some of the issues I've been having on the other topic, I've tried a number of new LCDs on this laptop, and there is power reaching the LED strip, but no discernible ground, so if the ground is switched...Leave a comment:
-
Re: Scavenge LED strips from laptop (Backlight Repair)
I was testing these just trying to use a current regulated bench power supply, and while I'm familiar with most basic electronics, for some reason I can't seem to trace how these are wired. I saw a schematic somewhere where some LED strips are grouped in groups of 4-5 and every 4-5 are reversed in polarity. But what appears to be a ground doesn't seem to trace to ground when it's actually in-circuit in the LCD panel driver board, and connected to the computer.Leave a comment:
-
Re: Acer 5534 No Backlight (LED)
(complying with advice from another, here's an inline picture)...Leave a comment:
-
Re: Scavenge LED strips from laptop (Backlight Repair)
I was actually abiding by someone else's post/suggestion that I shouldn't use in-line pictures because they cause problems on some people's browsers.
Either way, this should satisfy everyone if I leave the links above (which I can't edit anymore for some reason) and these pictures below,
I appreciate the input!...Leave a comment:
No activity results to display
Leave a comment: