I press the power button on my Mac Pro - it takes 3 to 4 min before startup chime comes on - does anyone know cause or solution please?

Bad disk drive?

Safe Boot?

Weak pram battery?

What model? is it looking for startup disk or net boot?

Reset SMC.

Take it in unless there is something you/we aren't seeing like an old or underpowered UPS or a bad PSU or other hardware issue. You took out and reseated the graphic card too - which one do you have? GT120? 4870? other?

Pull all the hard drives, easy enough, how long until the "?" comes on screen?

When did you last replace the boot drive or format it? And last repaired the drive? You don't have Lion Recovery so while you can use 10.6 DVD to repair I prefer a small maintenance emergency boot volume instead that would be current OS version and drivers.

AHT does not find issues users expect like graphic card and even some or many RAM DIMM issues.

Pull the disk drives like I said?

Got a spare drive? everyone should. Do a full wipe erase and install on it.

Or clone your existing system, but you will need a disk drive for that even.

Surely you have used and launched Disk Utility and seen some of what the window tabs present? to repair permissions, to verify and repair the disk drive, as well as from ERASE or PARTITION.

And always there is first step on bad shutdown or freeze or issue, the Safe Boot.

http://support.apple.com/kb/HT1455

How to clone your system:

http://macperformanceguide.com/Mac-HowToClone-backup.html

http://macperformanceguide.com/Mac-HowToClone.html

http://www.macupdate.com/app/mac/7032/carbon-copy-cloner

You are wiping the partitions and rebuild the drive from scratch.

Or just invest in a new drive, format, install, then Setup Assistant.

One suggestion The hatter made above is to remove ALL Hard drives and set them aside.

Then power on and see how long it takes to chime and come on (to a blinking question mark). This eliminates hard drive issues from the process.

-- If it still takes minutes, you may need to fiddle with your RAM Memory.

-- If it takes a quarter minute or less, the problem is in the drives.

Sorry that "boot drive" seems to be foreign concept or word.

No need or way that dust in a 2009 Mac Pro and startup chime would be related.

Zapping PRAM is sometimes all that is needed and that while very old been around for decade plus, SMC Reset if you don't also press the power button while unplugged is not really an effective but is useful.

Power outages, storms and other acts of nature can be harmful if you don't put your equipment, even modem, TV And other devices, running off UPS - they are more than just for power outages.

My trouble is there is learning curve, 20 questions, and no way to know what someone has done, knows, and might have trouble with.

Pulling the drives out is child's play. They are meant for that and is a good first step. And yes Grant is good with making things more English. Even though I taught programming concepts it often took months before new people began to stop thinking a disk drive as memory and yet that is where virtual memory resides.

Stripping the system down you did do, but just not with the hard drive, system drive, boot drive - call it what you want it is where the OS is and boot sequence looks at any and all drives, and a corrupt disk drive can even prevent booting from a DVD OS X Installer at times so removing it is necessary. It is DIY to upgrade and add disk drives and hopefully you have all four drive bays filled with data, backup, system and more.

Cloning is your system's insurance policy.

Off line and external and not on or connected when not needed.

Two. So one being backed up that is online, and 2nd on the shelf.

then recycle or something.

That is one safety net and should be done only as needed for the system.

Keep the system and data separate drives.

Let TimeMachine and clone both so you have your data safe.

Never have all your eggs in one basket and where they could be lost.

After a year or two replace your current drives and use the old ones for backups.

This will protect modem, surges, outage, and take some of the work load off the PSU so it is getting good cleaner power and doesn't have to do any work to regulate as much even though a PSU is designed for that. And PSU and UPS both, age and slowly degrade over time - buy more than actual wattage you need.

http://www.amazon.com/CyberPower-CP1500PFCLCD-Compatible-1500VA-Tower/dp/B00429N 19W/

My Mac Pro has taken a beating and wear on the outside but it still works probably better than it use to.

And for dust? skip canned.

i answered that once already at the top.

Best? CCC

And setup another drive for TM