I feel that the easy way out is to just get a new graphics card for your computer.
I assume that you have tried another monitor on your computer to see if it is that giving out.
I have been using emachines T1150 for like 4 yrs.now. Recently I started having symptoms like not recognising mouse and monitor feezes. Now when i start my comoputer, after 1-2 min. monitor shuts down itself. Talked to emachines support and they advised me to run through six floppy disks for set-up process and then restore CD( had tough time doing that as monitor was not giving me chance to complete any of the process). I could not run complete set=up process as disk 5 kept on throwing error. Went ahead and ran restore CD. Could restore OS and it worked ok for couple of days but now again i have same problem. Can anybody suggest me a directon before I jump to conclusion of buying new CPU.