Acer 5920G LCD Upgrade

MODS: if this is better in hardware then please could you move it over

Hello everyone! First post here so be nice

I recently bought a new screen for my acer aspire 5920g to upgrade the 1280x800 supplied screen. The new screen is WSXGA (1650x900), I've managed to get to the point of exchanging the screens however it seems as though acer only have wired up half the LCD cable. Now, I thought no problem, i'll wire the rest up myself. The only issue is that i'm not sure it is possible, there are not another 8 connections on the motherboard plug to wire up...... does anyone know if this is possible?

- Connection to inverter.



- Webcam connector



- Old screen datasheet left, new screen datasheet right



- LCD Connector (not full 30 pin connected)




- Motherboard connector



- Motherboard connector



- Second shot of LCD connector

 

This guide might help, found this while researching LCD upgrades for my Acer Extensa laptop: Acer Extensa Laptop 5620 Hotrod Overhaul Guide - Step 8 to the end covers the LCD upgrade portion.

 

This is where I actually got the idea

The issue i'm having with this guide is that the pins he says to use are already in use..... they seem to be either going to the USB webcam or the inverter. I'm worried that the connection might not support the dual lvds connection that the LCD requires.

Does anyone know if it is possible that the motherboard would have a custom connector to the lcd?

 

Sorry, I'm not here to help, but ask - are you sure that it's 1650x900 and not 1680x1050 (16:10)?

 

Yes, my apologies you are correct it is 1680x1050 (16:10), I was just remembering the resolution off the top of my head .

 

No problem. I'm sorry that I can't help, but I'll keep an eye how this would go. Good luck

 

does the motherboard connector allso only have 20 pins?
because i was allso thinking of upgrading the screen

 

You might get some more help in the Hardware section.

 

No the motherboard has a full 40 pin connector as seen in the photos above.

 

ok, so what u need is actually a pinout of the motherboard, searching the net now

actually u can use the pinout from the Acer Extensa Laptop 5620 Hotrod Overhaul Guide link

what u need to do is add a wire from

motherboard to screen
pin 12----------------pin 20
pin 11----------------pin 21
pin 10----------------pin 23
pin 9 -----------------pin 24
pin 8 -----------------pin 26
pin 7 -----------------pin 27
pin 6 -----------------pin 29
pin 5 -----------------pin 30


u should still have 12 pin free
8 wires for the webcam and inverter 4 each
and the 20 that is connected to the screen
that leaves out 12 wires that is unaccounted for if u say that there are wires in all 40 pins,
the guy from the instructables.com allso strips his for the foil or at least most of it,

if you were to do the same maybe u can see where the rest of the wires go

 

Hi Raserdk,

Yes, a pinout diagram from the motherboard is exactly what I need. The problem here though is that pins 5 - 12 are already used for something else, which makes me wonder if Acer have rerouted the pins on the motherboard to more a more useful function, for example usb for the webcam as you mentioned. I will count the left over wires, but they are not all in one strip, so how could I go about finding out which pin does?

I'm in the middle of making a mockup diagram of working out which pin is which. I'll see if I can finish it this evening and then hopefully work something out!

 

I think what is partly stated in that guide (tho unclearly) is that you can still use the higher resolution screens sometimes with the lesser number of LVDS pins, but you still have to rewire the pinout.
Maybe you could try that?

Also, what are the brands of your old an upgraded screen? Sometimes manufacturers whitelist certain brands.

 

Ok this is what I have managed to gather. It looks promising for another LVDS channel with 4 pairs of pin locations. The only issue is which pairs to link to what.



@niffcreature - the old lcd was an LG and the new panel is Samsung. I understand what you're saying but the pins on the LG and Samsung datasheets match pinf or pin name for name. The odd thing is that I didn't even get a garbled output just a black screen. I think it may need the odd and even clock to get anything out of it, but this is just presuming. However I could change the backlight of the screen so the power was ok.

Something I don't understand is what input the old screen is taking, on the Samsung Data sheet it states odd and even channels, I assume the 4 pairs will all be even or odd, or will there be 2 pairs of odd and 2 pairs of even on the LG LCD?

Edit: This would be sensible maybe?

 

Yup. Even tho pretty much all these screens have the same pinouts, the laptop will still sometimes read the firmware and block it out.

Heres how you can tell if this is happening. It sounds pretty dangerous but it really isn't.
-Start up your laptop with the old screen displaying as normal.
-Uninstall it and reinstall the new screen. Do not turn the laptop off.
-If you are too cautious, might want to try it while the laptop is on sleep mode.

I have a hitachi dual backlit screen with lower latency than most, and NONE of my 6 laptops will start up with it. But if I plug it in while the laptop is still on it works absolutely fine.

In your case, I am sure it will be garbled because of the resolution difference, but at least you will have more info.

 

Perhaps you and I should investigate this further, there was someone with an acer who encountered this and got some log files of the laptop trying to use the wrong firmware, or something. I don't think its a really complex problem, some of the BIOS modding folks can probably fix it.

 

Ok, I tested that and the screen still didn't show anything which is kind of positive I guess means I won't have to reverse engineer any firmware! I will try and wire up some of the pins tomorrow and see if I can get any sort of output. If I get the odd clock and a pair of odd inputs would you expect to be able to see at least something?

 

Ok, so I found the Even Data Clock pins, 18 and 19. Which 'boots' the screen but now I'm fiddling with the correct colour channels to stabilise the input.

• 
• 

 

Ok. This has driven me mad, I can't get the right combination of cables and tilting the screen changes the connections as I have make shifted the wires. Is there any way I could possibly tell which pin is which colour set through some simple tests and then at least I can rule out bad connections?

 

hmm, well this is an accomplishment indeed! Even with the mixed up colors.

I'm not sure, maybe you should get an oscilloscope. And/or buy a new cable. I think that would be the only way other than trial and error.

 

Right, i've made an offer to someone on ebay to pick one of these cables up for 9 quid, I will then use the cable from my current cable to supplement the missing wires on my new cable and get a perfect connection. This will then let me properly deduct if this is possible. I am inclined to believe at the moment that it is an issue with my wire quality rather than an issue with the signal. I am using cheap single core wire with the ends filed down for the flat surface to the LCD connector, not ideal but enough to get an idea if it will work or not, which it does so i'll try and do it properly when the new cable arrives!

 

i hope u succeed,
because u have to write down wich wire does what hehe
so others can do the same

maybe this can help,

 

This is the cable I have bought to use:

ACER ASPIRE 5315 5720 5920 LCD CABLE DC02000E100 on eBay (end time 26-Mar-11 22:00:03 GMT)

It looks like it may have a full 30 pin wireout from the photo but if not I will just strip it and use the cables to supplement my current one. You never know I might get lucky and it will already be wired properly

@raserdk: I have already done a pin out diagram on page 2, I will do an updated one with a better view when I work out the exact layout.

 

From these photos:

New Acer Aspire 7720 video LCD Cable DC02000E100 ICK70 | eBay

You can see a full 30 pin output, lets hope eh!!

 

Ok a bit of bad news. I think I've burned something. I tried using the new cable I got straight without any modifications. The laptop would not turn on and the power supply was flashing, as if it was changing and then discharging. I then proceeded to modify my cable and it seems as though something went pop during this (now obviously idiotic) act. My new samsung lcd shows a black screen with dark vertical green lines and the original LG screen shows a full white screen with a few vertical anomalies on the upper half. So, bad times huh!

My question is do you think I've knackered the graphics card, the inverter or something else? I really hope it's the inverter as they are cheap unlike the graphics chip.... However the screens light up so this means they are getting power yes? I can also alter the backlight power which also points towards a graphics chip problem

I have tried connecting an external screen but I don't know how to route signal to it without being able to see the screen to change the output...

Any suggestions welcome.

 

Ok, better news.

I have the laptop outputting fine to an external display. This means that the graphics chip is fine (yes?). So now, I believe the problem to either be the inverter, or is there an LVDS chip that runs between the lcd and graphics chip that could have been fried?

EDIT:

Even with the wiring return to exact original spec it's still a no go, however with the original screen there is no flickering, just every pixel is white. I am thinking (see: hoping) that it is inverter related and the Samsung uses pull high setup (i.e. the pixels are off until a high signal is recieved) and the LG uses a sunk setup (i.e. pixels are always on until told to turn off) again I'm clutching at straws so....

EDIT2:

I played with the ground wires and now the LCD is flickering again in 3 bands, is there anyway I could manually ground the wires to check if it is a problem with the cabling?
-------------------------------
|
| Vertical lines here
------------------------------------
|
| Plain white band
------------------------------------
|
| Vertical lined band
----------------------------------

 

any news?
sorry to hear that your laptop might be broken

 

1 3,3v 21
2 inverter 22 3,3v
3 web camera 23 3,3v
4 web camera 24 inverter
5 web camera 25 inverter
6 web camera 26 inverter
7 B D1+ 27
8 B D1- 28 ground
9 inverter 29 B D2+
10 A-clock + 30 B D2-
11 A-clock - 31 ground
12 ground 32 A D0+
13 A D1+ 33 A D0-
14 A D1- 34 Ground
15 ground 35 A D2+
16 B D0+ 36 A D2-
17 B D0- 37 Ground
18 ground 38 B Clock +
19 DDC data 39 B Clock -
20 DDC clock 40 ground

This is from watching the tables... hope it helps