Compaq Presario CQ62 Wireless Problem
Problems that usually occur is system (network manager) can't browse available access point, regarding to this problem you can solve by adding wireless connection manually using the correct access point name and wireless security key. Other way, you can search access point trough terminal using iwconfig or iwlist, see the exemple bellow.
$ iwconfig eth1
the result should be like this 
eth1     IEEE 802.11g  ESSID:"OSU_PUB
         Mode:Managed  Frequency:2.427 GHz  Access Point: 00:0D:9D:C6:38:2D  
         Bit Rate=48 Mb/s   Tx-Power=20 dBm   Sensitivity=8/0 
         Retry limit:7   RTS thr:off   Fragment thr:off
         Power Management:off
         Link Quality=91/100  Signal level=-39 dBm  Noise level=-87 dBm
         Rx invalid nwid:0  Rx invalid crypt:860  Rx invalid frag:0
         Tx excessive retries:0  Invalid misc:39   Missed beacon:8
the bold line above (OSU_PUB) is exactly the name of access point, complate guide how to add wireless access point by manual through terminal can be complately find in here.

Compaq Presario CQ62 No Sound
The common problem is laptop no sound or if the speakers are not working but the headphones are, you can follow the instruction bellow, do with command line :
sudo add-apt-repository ppa:ubuntu-audio-dev/ppa
sudo apt-get update
Install the linux-alsa-driver-modules package
sudo apt-get install linux-alsa-driver-modules-$(uname -r)

Backlight Brightness Control not working
Some of compaq presario have experience with this problem, foremost laptops that running Ubuntu under 10.10 (Maverick Meerkat), we got a lot of answers in a forum but sometime not work properly. the main problem is the GNOME itself, you can fix it by re-installing GNOME or try to install new version of your distro (Ubuntu 11.04 maybe), other way we have tricky solution that usually work, do with command line under #root.
echo -n 50 > /proc/acpi/video/VGA/LCD/brightness
50 is percentage of brightness, you can replace the 50 with: 37 12 25 37 50 62 75 87 or 100. After doing some action above, don't forget to reboot your laptop and your problems should be solved after that (i hope so).