Autore Topic: Laptop with broken video card - partial recovery  (Letto 9137 volte)

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Offline JackTheVendicator

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Laptop with broken video card - partial recovery
« il: 04 Gennaio 2011, 14:49 »
Scrivero' questo articolo in Inglese perche' ho intenzione di segnalarlo a qualche sito (es. Hack a Day), sperando che possa essere utile a qualche altra persona con la scheda video presa di mira da Murphy.

A couple of weeks ago, my laptop screen went suddenly black. Using a "backup" pc, I searched infos on the problem and found that there's a certain chance of thermal faults on G86 chips, used in 8600M GT video cards. I promptly tried to reflow the card, but the situation actually got worse (something on the 3.3V line of the card went short circuit, preventing me from turning on the computer). I didn't want to hack up a solution, since I preferred to enjoy the holidays instead.
Yesterday evening I actually realized that I needed some data that were on the laptop, and that I didn't have *any* usb-to-sata box or computer with a sata controller. So I needed to boot that laptop on linux *at all costs* and make it appear on the LAN, using a bit of dexterity with blind-typing, some hardware I had in my "toolbox" and great Stefano Viola's (EstebanSannin) suggestions :).
This is a small list of the steps I took to take control of the box (the photos & screenshots have been taken few minutes ago):

Since the pc has no VNC or SSH server installed, I have to go with a shell on a USB serial port (recent laptops don't have real serial ports). I remove the failed video card and connect an Arduino to the laptop and a TTL-converter to the backup pc, and join both (TX with RX, RX with TX, 3V3 with converter VCC, common GND). Now I have an hacked-up nullmodem cable:


I blind type the following:
Codice: [Seleziona]
(enter to boot linux from GRUB, then wait a bit)

CTRL-ALT-F1 (to make sure I'm on the first VT)
my username
my password
sudo su
my sudo password
modprobe pl2303 (not necessary, since Ubuntu automatically detects USB devices)
getty 115200 ttyUSB0

The Arduino LEDs blink once, so I should now have an open serial shell @ 115200 8N1... let's try:

It works! ;D

So, i login as root, connect laptop's ethernet (Ubuntu automatically gets an IP from DHCP) and simply do:
Codice: [Seleziona]
apt-get install openssh-server vnc4server (sshd starts automatically after install)
ifconfig eth0 (to write down the assigned IP)

I can now connect over SSH as normal user, and tweak the VNC server configuration:
Codice: [Seleziona]
mv /usr/bin/nm-applet /usr/bin/nm-applet.orig (to not interfere with the already assigned IP)
vnc4server (it should ask you for a password on inbound connections)
killall Xvnc
vim ~/.vnc/xstartup (replace twm & with gnome-session &)
vnc4server
(xstartup mod taken from here http://www.linuxquestions.org/questions/linux-newbie-8/starting-gnome-session-over-vnc-268828/)

And VNC it's now ready in all its glory, at IP:1


Full hardware setup, including audio redirect to audio system line-in (laptop is on, but screen is obviously blank):


--EDIT--
Featured on Hack a Day! ;D
« Ultima modifica: 05 Gennaio 2011, 13:36 da JackTheVendicator »

Offline machico

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Re:Laptop with broken video card - partial recovery
« Risposta #1 il: 05 Gennaio 2011, 09:24 »
pubblicato su hack a day ;) ci sono arrivato da li .. compl

eppoi hai trovato una soluzione ingegnosa, il probabilmente avrei smontato l'hdd e lo avrei montato su un pc di supporto -- questo cmq sia di lezione :P a tutti -- installate sempre ssh  ;D
« Ultima modifica: 05 Gennaio 2011, 09:28 da machico »

Offline machico

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Re:Laptop with broken video card - partial recovery
« Risposta #2 il: 05 Gennaio 2011, 16:32 »
sei stato segnalato anche qui http://www.electronics-lab.com/blog/?p=8028

Offline nsm21ilp

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Re:Laptop with broken video card - partial recovery
« Risposta #3 il: 26 Settembre 2011, 19:15 »
JackTheVendicator avuto un momento molto difficile. Dopo tutto avrebbe potuto trovare una soluzione molto buona che in seguito mi hanno aiutato praticamente.
Grazie
JackTheVendicator