Aspire 6920G LCD issues (most issues ruled out)

Hi there.

I run into trouble with 6920G that someone asked me to fix. Screen looked like this.
I assumed it would be nVidia 9500M GS going all bumpgate on me but it wasn't.
Laptop works fine with an external screen and the card itself (MXM II) works fine in another 6920G- with an internal screen.
Windows did not detect notebook screen at all- it would see an external one but not the internal one.

I moved to another possible culprit and replaced the LCD cable- didn't help.

So I ordered new screen. Since 16" ones are not being made anymore prices are ridiculous for a 1366x768 (LTN160AT01-A01) so I ordered 1920x1080 (LTN160HT01-A02) one which was actually cheaper. I also bought dual-LVDS cable.

Aspire 6920G is a dual-LVDS unit and has been sold with Full HD screen.
I bought a proper cable, the same screen that was originally used by Acer according to a service manual (different revision though- A02 instead of A01)
I ended up seeing this- more or less the same thing I'd see with the old screen.

The difference is this one (Full HD one) is being detected by Windows can be set to Full HD resolution and so on- while it still doesn't show anything.
Drivers have been re-installed too.

To sum it up issues already ruled out:

-cable (tested with two WXGA and one WUXGA cables)
-LCD screen- two units show exactly the same. It's unlikely that both failed.
-drivers (re-installed and installed new ones)
-MXM card (works with an external screen and with an internal one in another 6920G)

I have two other ideas but will keep quiet about those not to suggest anything (especially that both are very unlikely to work).

I'd be grateful for any and all assistance.

 

If you plug in the other 6920G's screen, does it work?

Also, try applying a very thin layer of solder on the MXM card's pins. This may sound weird, but it can help when the card is not making good contact with the slot (e.g. due to slot wearout).

EDIT: Can you read the internal display's EDID correctly? (Use Linux to test this - Windows caches the EDID from previous boots, so even if EDID readout is failing, it will appear to succeed.) The pictures clearly show the card outputting an LVDS signal with insufficient horizontal resolution - the sign of a failed EDID readout.

 

Hello all,

This is my first post so bear with me. I was wondering ~downloads~ if you had any luck fixing your friends computer.

I am also trying to fix a computer for a friend. It is a Acer Aspire 6930. The screen was working intermittently, then it just turned black and stayed that way. I could get it to flash when I push fn+f6.(toggle between external and internal monitor)

A new inverter made no difference. A new VGA cable brought the screen back to life but it looks like ~downloads~ posted pictures. The computer boots fine though and everything works great on an external monitor. I was thinking the lcd screen went bad and would need replacing but then I came across this post. After seeing what ~.NetRolller 3D~ posted about the EDID, I googled a bit and discovered that some Acer computers (someone mentioned a 6920G) have bad EDID. I still have more reading to do, but it seems that you can correct it by changing the last 2 characters and then reprogramming a EEPROM chip. I am curious how the chip would have become corrupted in the first place. Also why does the original VGA cable give a black screen and the new cable activates the CFL but displays the pattern ~downloads~ described above. I have several pictures, I will upload them when I can get them off my tablet. The screen is the lower resolution 1388x768 not the 1080 version. I think I read that the problem with the acers and the EDID was that they were trying to use 800x600 instead of 1388x768. I still have more research to do, I will check the EDID with linux as ~.NetRolller 3D~ suggested as soon as I get a flash drive.

P.S. I also tried restoring the bios to it's default setting, no luck there.

Thanks all!
Nate

 

@NetRolller 3D

Unfortunately I couldn't test the other screen- MXM was tested by my friend on his mother's laptop. It was easy enough and did not involve serious dismantling of the laptop. Asking to test the LCD would be too much.

I tried to move/rock about the MXM card a bit while the unit was on and holding screws were removed- no change in the pattern displayed so I assume it's not lack of contact between the pins.
I was forced to use this silly method as I'm seriously down on supplies- no solder and leftovers of thermal compound

As for EDID- I haven't had a chance to check it in non-Windows environment (I think 6920G doesn't boot from USB so I'll have to find a DVD somewhere) but EDID read by PowerStrip looked OK apart from the fact that it doesn't seem to show established timing bitmap- just standard timing for native resolution.

One more thing- LCD gets black after a short while- backlight is on so these are crystals rotating- no idea why. Here's how it looks.

@techwizards

There's more of us I see
We tried the same solutions and both got nowhere...

EDIT: Nah- my bad- it supports USB boot. I'll test it.

EDIT2: Reading EDID under DOS got me nowhere- I got EDID for an external monitor but nothing for the internal one.
When I disconnected the external one and used the command blind and then connected the external one to see the result there was no output.

 

This link looks promising
Step by step fixing a corrupted EDID on Acer
It will also tell you how to make sure you don't program the wrong monitor by mistake =)

EDIT: I went through my history and here is someone perhaps with the same problem who fixed it. I am putting the text here because the page has dozens of irrelevant answers but here is the link if you want to see the source......

Apparently some series of Acer notebook came with BAD_EDID laptop display. The only thing wrong is the checksum which is 9D and should be 1D. Powerstrip 3.76 (registered version) managed automatically to correct EDID. (cari di Mbah google yah..)

There is no problem with drivers from 101.x series, but with any newer driver max. resolution is 1024×768 and the picture is in left upper corner of the screen with black bar on the right and smudged taskbar to the bottom of the screen. After installing and restarting resolution is set to 800×600 what results in white screen whit thick black bar slowly appearing on the screen.

I hope this will save someone some time, because I was about to send laptop to service when I figured that out. Contacting through e-mails and phones with acer and local authorized service didn’t solve anything they just said that I should reset laptop to factory defaults, in other words don’t install any new driver and everything will be fine.

Just thinking about future
dPrince Of Smart
berjalan di bumikupijak<a/>

 

bump

 

I downloaded phoenix edid editor but it could not find edid in registry. Monitor Asset manager was able to show the edid for my external and internal lcd monitor though. It list two real-time entries both for my external LG and 2 Registry-Active entries. 1 for the external LG and 1 for the internal Samsung (matched 160AT01-A02 to model on back of LCD to confirm, registry creation date was today). I looked online and found a post by someone with the same lcd and the EDID seemed to match exactly. I installed new intel graphic drivers and chipset drivers and it would let me set the resolution to what should be the native 1366x768 but still black bar in center and vertical lines with no distinct image.(will get pics uploaded soon!) I tried saving as .inf and loading custom driver for the plug and play monitor under devices and still no usable display. Since I can read the EDID and it matches the one I found online for the same lcd then does that mean this is not an EDID problem but a broken LCD problem?
Thanks,
Nate

 

Edit: Here is the information from MAM....

Monitor
Windows description...... Samsung SEC304C (SEC304C EDID Override)
Manufacturer............. Samsung
Plug and Play ID......... SEC304C
Data string.............. 160AT01-A02
Serial number............ n/a
Manufacture date......... 2008, ISO week 0
Filter driver............ EDID Override
-------------------------
EDID revision............ 1.3
Input signal type........ Digital
Color bit depth.......... Undefined
Display type............. RGB color
Screen size.............. 350 x 200 mm (15.9 in)
Power management......... Not supported
Extension blocs.......... None
-------------------------
DDC/CI................... n/a

Color characteristics
Default color space...... Non-sRGB
Display gamma............ 2.20
Red chromaticity......... Rx 0.580 - Ry 0.340
Green chromaticity....... Gx 0.310 - Gy 0.550
Blue chromaticity........ Bx 0.155 - By 0.155
White point (default).... Wx 0.313 - Wy 0.329
Additional descriptors... None

Timing characteristics
Range limits............. Not available
GTF standard............. Not supported
Additional descriptors... None
Preferred timing......... Yes
Native/preferred timing.. 1366x768p at 60Hz (16:9)
Modeline............... "1366x768" 72.330 1366 1414 1446 1526 768 770 775 790 -hsync -vsync

Standard timings supported

Report information
Date generated........... 4/8/2012
Software revision........ 2.60.0.972
Data source.............. Registry-Active
Operating system......... 6.1.7601.2.Service Pack 1

Raw data
00,FF,FF,FF,FF,FF,FF,00,4C,A3,4C,30,00,00,00,00,00,12,01,03,80,23,14,78,0A,87,F5,94,57,4F,8C,27,
27,50,54,00,00,00,01,01,01,01,01,01,01,01,01,01,01,01,01,01,01,01,41,1C,56,A0,50,00,16,30,30,20,
25,00,61,C6,10,00,00,19,00,00,00,0F,00,00,00,00,00,00,00,00,00,1E,B4,02,74,00,00,00,00,FE,00,53,
41,4D,53,55,4E,47,0A,20,20,20,20,20,00,00,00,FE,00,31,36,30,41,54,30,31,2D,41,30,32,0A,20,00,B8

 

We're in the same boat- which is sinking

Monitor
Manufacturer............. Samsung
Plug and Play ID......... SEC304C
Data string.............. 160HT01-A02
Serial number............ n/a
Manufacture date......... 2008, ISO week 0
Filter driver............ None
-------------------------
EDID revision............ 1.3
Input signal type........ Digital
Color bit depth.......... Undefined
Display type............. RGB color
Screen size.............. 350 x 200 mm (15,9 in)
Power management......... Not supported
Extension blocs.......... None
-------------------------
DDC/CI................... Not supported

Color characteristics
Default color space...... Non-sRGB
Display gamma............ 2,20
Red chromaticity......... Rx 0,580 - Ry 0,340
Green chromaticity....... Gx 0,310 - Gy 0,550
Blue chromaticity........ Bx 0,155 - By 0,155
White point (default).... Wx 0,313 - Wy 0,329
Additional descriptors... None

Timing characteristics
Range limits............. Not available
GTF standard............. Not supported
Additional descriptors... None
Preferred timing......... Yes
Native/preferred timing.. 1920x1080p at 60Hz (16:9)
Modeline............... "1920x1080" 138,650 1920 1968 2000 2080 1080 1082 1087 1111 -hsync -vsync

Standard timings supported

Report information
Date generated........... 2012-04-08
Software revision........ 2.60.0.972
Data source.............. Real-time 0x0041
Operating system......... 6.0.6002.2.Service Pack 2

Raw data
00,FF,FF,FF,FF,FF,FF,00,4C,A3,4C,30,00,00,00,00,00,12,01,03,80,23,14,78,0A,87,F5,94,57,4F,8C,27,
27,50,54,00,00,00,01,01,01,01,01,01,01,01,01,01,01,01,01,01,01,01,29,36,80,A0,70,38,1F,40,30,20,
25,00,61,C6,10,00,00,19,00,00,00,0F,00,00,00,00,00,00,00,00,00,20,91,02,64,00,00,00,00,FE,00,53,
41,4D,53,55,4E,47,0A,20,20,20,20,20,00,00,00,FE,00,31,36,30,48,54,30,31,2D,41,30,32,0A,20,00,45

 

Interestingly after switching back to the original vga cable and checking the edid it showed up differently. Also says digital flat panel instead of generic pnp monitor under monitors. I tried loading the custom inf driver with the correct edid information and it would let me change the resolution to the correct setting but still nothing on the screen. I wonder if the new vga cable is defective/wrong but working better then the original such that it can now get edid information but still not display properly. here is the information showing up under MAM with the ORIGINAL vga cable.....

Monitor
Windows description...... Digital Flat Panel (1024x768 60Hz)
Manufacturer............. Microsoft (LVDS/eDP)
Plug and Play ID......... MS_0003
Serial number............ 13
Manufacture date......... 2002, ISO week 0
Filter driver............ None
-------------------------
EDID revision............ 1.3
Input signal type........ Digital
Color bit depth.......... Undefined
Display type............. RGB color
Screen size.............. Undefined or variable
Power management......... Active off/sleep
Extension blocs.......... None
-------------------------
DDC/CI................... Supported
MCCS revison............. 2.1
Display technology....... TFT
Controller............... Unknown
Firmware revision........ 0.1
Firmware flags........... 0x00010068
Active power on time..... 1262 hours
Power consumption........ Not supported
Current frequency........ 59.90kHz, 74.90Hz

Color characteristics
Default color space...... sRGB
Display gamma............ 3.55
Red chromaticity......... Rx 0.625 - Ry 0.340
Green chromaticity....... Gx 0.285 - Gy 0.605
Blue chromaticity........ Bx 0.148 - By 0.063
White point (default).... Wx 0.281 - Wy 0.309
Additional descriptors... None

Timing characteristics
Horizontal scan range.... 0-235kHz
Vertical scan range...... 0-60Hz
Video bandwidth.......... 70MHz
CVT standard............. Not supported
GTF standard............. Supported
Additional descriptors... None
Preferred timing......... Yes
Native/preferred timing.. 1024x768p at 60Hz
Modeline............... "1024x768" 65.000 1024 1048 1184 1344 768 771 777 806 +hsync +vsync

Standard timings supported

Report information
Date generated........... 4/8/2012
Software revision........ 2.60.0.972
Data source.............. Registry-Active*
Operating system......... 6.1.7601.2.Service Pack 1

Raw data
00,FF,FF,FF,FF,FF,FF,00,36,7F,03,00,0D,00,00,00,00,0C,01,03,80,00,00,FF,2F,00,00,A0,57,49,9B,26,
10,48,4F,00,00,00,01,01,01,01,01,01,01,01,01,01,01,01,01,01,01,01,64,19,00,40,41,00,26,30,18,88,
36,00,00,00,00,00,00,1E,00,00,00,FD,00,00,3C,00,EB,07,00,00,00,00,00,00,00,00,00,00,00,00,00,00,
00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,00,58

EDIT: I cannot seem to change resolution on internal display to 1366x768 even after loading custom driver created from correct edid obtained with other vga cable. It only lets me go to 1024x768. I though I was able to change this before to test, I guess I must have been wrong. I hope you are doing better then I am. My friend cannot afford a new screen and I don't think another cable to test. I am getting ready to reassemble and have her hook it up to external monitor. Just to confirm does windows 7 let you use custom inf to bypass edid information or should I be trying this in Vista?

 

I don't know about Win 7- I'm testing as it is which is Vista.
When I run out of patience I'm buying a new mobo.

 

what are the Part numbers of the cables.

new and old.

 

In my case the old one has a sticker saying:
KJ16" LCM CABLE (WXGA)
6017B0158801
That was the original cable and I replaced it with the same type of cable first.
Afterwards I upgraded the screen to Full HD which required a new cable which is 6017B0157201 and says WXGA/WUXGA.

The first one obviously fits as it was the same as the original one and the second one is listed as a cable for 6920 too.

 

hmmm.... cable for wuxga is correct. acer pn: 50.APQ0N.012, Inventec Corp pn: 6017B0157201

maybe a bad wuxga screen or issue with the mainboard.

 

I'm thinking mobo. Full HD screen is showing the same symptoms that the original HD Ready did. It's unlikely that both screens are gone.

Went through three cables and two screens and MXM module has been successfully tested on another notebook- it looks like a mobo issue at this point.
I'm going to try Linux for a change- maybe I'll find something interesting there (like EDID missing).
If not- I'm going for a new mobo- I found one for $80 that's as cheap as it gets.

EDIT: Ubuntu recognizes the display but it doesn't help in any way.

 

Newsflash- new mobo, new LCD cable and new LCD screen and still the same.
Only other options are MXM card which worked fine on another laptop of the same type and works fine with an external screen an an inverter which should either work or not (no in-between).

I'm going to buy a new inverter- it's the most logical and the cheaper part to replace although my logic is a spectacular failure so far.

 

Actually, my guess now is that BOTH your original and new LVDS cable are broken. (Check with a multimeter.)

 

I doubt that since I have three LVDS cables and all give the same result.

 

I had problems with my Acer 6930ZG screen, - it flickered a lot. I opened it and I isolated the screen cables with tape, and then the problem was gone! However, I don't think this will help you since you have tried to replace the cables, and it looks like the problem you have is worse that mine, but you can give it a shot.

 

I wonder, does the screen itself work?

 

That- I don't know, but since I have two and both show exactly the same "maze" I find that unlikely that both are faulty in the same way.
Unfortunately it's a CCFL LCD which requires an inverter and I don't have any other laptop with matching connectors to cross check with this particular one.

My friend mother's laptop can't be used for this as it requires quite a lot of disassembly with this model and it's slimly too much to ask.

 

It's definitely not the inverter - that is only responsible for the backlight. Inverter failure can't cause garbled image.

What happens if you wire up a completely different display (e.g. one of a different size) with the same connector? Preferably try a screen made by Chi Mei - their screens (though otherwise utter cr@p) are the best at decoding corrupted LVDS signals.

 

Technically I agree- it can't be an inverter but I'm running out of options.
New inverter and new GPU are the last options still on the table.

With GPU having been tested and an inverter being the only other common denominator I'm replacing it just to rule it out.
If it doesn't help I'll try to swap GPUs with a friend- mine works in his notebook- we'll see if his fails in mine.
If that happens I'm scrapping the whole thing- new GPU, new cable(s), new mobo, new inverter and new LCD and still the same thing?!
That would be impossible.

I have a LED backlit display with matching connector- not sure if it's supposed to work though.

 

I don't know, check the datasheets for both LCD panels.

 

You could try both a bios and vbios flash and see if that solves your problem


Edit* if you get fed up with it, I would be happy to take the machine off your hands.

 

I've managed to solve this issue. And by solve I mean started troubleshooting process from the beginning again.

To remind you- I've had my MXM card tested in an identical notebook (it worked fine on every boot and performed fine under 3D testing routines) and it's been working fine on "my" notebook but only with an external screen
Taking that into consideration I concluded it's fine.

Since I've replaced everything else I decided to start from scratch and borrowed the card from a friend who tested mine earlier an gave him my MXM module to test.

Guess what- his module works fine with my notebook while mine does the same thing for him it does for me, even though it used to work fine when I asked him to test it.
It's the most expensive card replacement procedure in history

 

Hmm... I guess when he tested it before, he pulled the MXM heatsink screws tighter than in his new test. The extra pressure caused the cracked DDC bump to gain contact again. A reflow would likely help.

Moral of the story: Don't let the 9 in "GeForce 9500M GS" fool you - it's still a GeForce 8000-series card, with all the problems inherent in that series.

EDIT: Reading the specs of both, it appears that the 9500M GS is not merely another 8000-series card - it is a flat-out rebranded 8600M GT. NotebookCheck talks about "internal optimizations" - however, the differences seen in benchmarks are consistent with pairing the 8600M GT with a T5xxx/T7xxx-series CPU, vs. a T9xxx-series one for the 9500M GS.