Sleep mode when screen is at 90º

A few months ago i bought an iBook G3 Late 2001 very cheaply for a start to a PC/Apple collection. When i bought it i knew the problems that the seller showed, such as the bad reddish colored screen with dirt inside and the problem with the sleep mode. When i recieved it, the original HDD (Toshiba 15GB) was failing too, so i replaced it with an older but more reliable IBM 20GB HDD and in the process of replacing it, i tried taking out the magnet on the lid to see if it would help but no sucess. With that in mind, what can i do to resolve the sleep problem?

I'm also thinking in replace the cells on the battery as it's long dead but is there a diagram on the conections of the batteries on the internet?