What type of mac? How old is it? What type of monitor and how old is it? When are these broken images and dots appearing and are they covering the entire screen or just part? The more info you can provide, the easier troubleshooting will be.
G5 tower. Twin 2ghrtz. 3.5 gb ram. -- 2 flat screen monitors, 23" cinema HD display & 20" display -- Whole rig is 5 or 6 years old -- problem exists on both monitors -- Tiger on one drive, Leopard on another problem occurs when booted on either system, or even when booted from optical install disk or disc warrior disc
problem has been intermitant for several months - repeated shut downs and startups would clear it up and machine would run ok for several days then happen again -- as of today, doesn't seem as if it's going to go away -- I' ve been told that i may have a bad graphics card -- also that i may have a bad driver off some sort -- card has two connectors for monitors
When problem is severe, i lose control of machine
Ok, because it is two different monitors, I'd rule out bad monitors.Because it occurs when running from all different sources (hard drives, optical drives, etc), then I'd rule out software or system. I'd even rule out it being a bad driver, because it would mean that all drivers are corrupt on all startup drives. Very unlikely.What's left? Video Card, Logic Board and RAM. Most likely culprit would be the video card. There are a few things you can do to make sure that it isn't the Mac itself and in board cache causing the issues. I'd suggest a PRAM reset and then a Safeboot. If the problem returns, I'd point at the video card.First let's reset the PRAM on the computer.1) Shut down the computer.2) While the computer is shut down, locate these keys: command (has an apple on it), option (sometimes called alt), P, and R.3) Turn the computer on, then press and hold Command-Option-P-R before the gray screen appears.4) Hold these keys down until you hear the startup sound a total of 3 times.5) Release the keys.Next, let's try a Safe Boot. This will perform several clean up procedures that may be affecting the machine's performance and startup as well as clear out any cache here as well.1) Shut down your computer completely.2) Start up the computer and immediately after the startup chime, press and hold the Shift key3) Once the gray Apple and progress indicator appear, release the Shift key4) Note: Startup will likely take substantially longer than normal (20 - 30 minutes is not unheard of)5) You should have to login to your account, even if it normally does so automatically.6) Shut down the computer.7) Restart and see how the monitors are acting.
I should have mentioned something earlier that may be significant here. Early on in this trouble, I ran the Apple hardware test that came with the machine. I ran the long test - about 2 hours. It told me that everything tested OK. With this in mind, do you still think I should perform the actions you reccommended?
Yes. Do both the PRAM reset and the Safeboot.
Thanx, Travis. Will do. -- Phredd
Good luck and keep me posted.
Will try this tomorrow. Thanks for the info and if I need add'l assistance, I'll be back for another question and try to get you.