I got korg pa800 my touch screen is lighting up but nothing is appearing on it. I interchanged the bottom cover along with the complete power supply unit. No Change. When i turn on, there is a faint light on the screen and stays like that for ever. The pa 800 logo never comes on. Any suggestions please?

SOURCE: Korg pa800 mic input makes funny noise

First turn the unit off then rotate the input level volume control. If it feels loose pull up lightly on it as you do this. Also rotate all your controls that you don't normally use a lot. Chances are the pots are dirty. If that doesn't help you might want to check all the connectors inside the unit if you feel confident enough to go poking around. Other wise I suggest that you find a shop that will fix the problem. If you do go poking around make sure the units unplugged and that you have grounded yourself against static discharges. 

SOURCE: pcm ram problem for korg pa800

http://www.musitronics.org/ Try here but apparently they are on holidays until August 16. There is also an ongoing discussion athttp://www.korgforums.com/forum/phpBB2/viewtopic.php?t=44624 Hope this helps.

SOURCE: WHAT KIND OF PCM RAM MEMORY IS USED IN KORG PA800

Here is a site IF you are having problem with the PCM RAM. It sounds like you might even get a free replacemnet part.

http://www.korgpa.com/pa_root/en/products/pa800_faq.html

SOURCE: os system not loaded! hard drive was totally formated. PA800

Hi, have you solved this problem yet? If you have, share the solution with us please! :)

SOURCE: Korg PA800. Ram Upgrade

The pa800 has a fixed amount of Ram at 64mbs and it is not physically possible to upgrade the Ram. The pa2x has a removable128mbs Module and that can be upgraded via a 256mb Module from Korg.
Keith [mrniceneasy - KorgForums]