Thank you so much for the detailed explanation, Jon. You know.... I have a laptop and I don't have a MAC but I read your troubleshooting non-the-less. I got to the last paragraph and realized something that I was told happened a couple of days ago that might be relevant. My room mate was home when this happened so this is second-hand knowledge. She was watching tv when the power went out then, a second later, there was a big POP down the street (a transformer maybe?). Everything still worked with the computer though; however, maybe it just needed to be power-cycled.

Any other comments will be greatly appreciated!

:-)~MIKE~(-:

On Wed, Sep 17, 2014 at 6:56 PM, Jon Kettenhofen <subs@kexsof.com> wrote:
Hello Michael,

I'm curious, did you buy this quad new or did you buy it used or is it a work computer owned by a company?  I get the feeling that you bought it used.

There's almost always a reason for failures and it's usually a problem that can be isolated.  If it's a part, it can be replaced.  If it's something else, it can be fixed.

When stuff like this starts to happen, it may be one of three things: a loose connection or a bad motherboard or a power supply.  Apple builds solid hardware but sometimes it gets abuse or just used in a poor environment with too much heat and/or moisture or just takes a physical beating - they are rather heavy.  Also quads, I believe, have water cooling.  I have seen at least one report of leaks.  That's usually easy to rule out if there's no leaks.

So where to begin?  Well, the pedant is back!

You may want to take some anti-static electricity precautions.  First, disconnect the Mac completely from all exterior cords, wires, etc.  Lay it on its side where there is plenty of light, a clean worktop area and a Phillips screwdriver.  As you have seen, it's easily taken apart, at least the easy pieces need only your hands.  Pull the fans out, take the video and other cards out, unhinge and pull the memory sticks out and so on until you are puzzled how to get the cooling shrouds out. (Don't do that.) Inspect everything.  Look for any corrosion.  Remove as much dirt and dust as you can with an air duster can (take care here, the these cans may contain hydrocarbons that are flammable and they should not be inhaled!).  If you use an air compressor, be gentle and use lower pressure less than 40psi.  What you can't get out with air, start with a clean microfiber cloth and wipe without generating static (i.e. don't rub hard).  Make sure all the connectors are clean and shiny before reassembling.

We call this clean and re-seat the boards.

Make sure you put the same memory sticks back into the same slots - it usually matters or makes a difference.  If you don't remember, read up on it from a manual, usually online at Apple.com.

Memory sticks are tricky because they often won't reseat properly without strong pressure.  First, make sure the middle slot on the memory stick is lined up with the ridge in the bottom of the connector.  The slots are offset from the middle on purpose, they are only supposed to go in one way.  (Having burned out a memory stick by forcing it in backwards, I can speak from experience! Won't do that again!) The way to handle this is to use two hands, with thumbs or your choice of fingers at each end of the board. Making sure the stick is aligned correctly in the connector; push FIRMLY down until both ends of the connector snap into the stick.  Main logic boards are epoxy and embedded fiber, are very strong and can take a little flexing without
hurting them.  Same with memory sticks.

Make sure the memory is seated well - it may take close inspection with a flashlight.  If the sticks are all the same size, then no stick should be higher than the lowest one.

OK, reassemble the computer.

Testing the power supply can be difficult.  It's easier with a common desktop PC because the power connector is almost always on top of the board and easily accessible.  It's not enough to test a power supply out of the computer because it won't be under load.

Here's how an expert taught me to test the power supply on a desktop PC (but not a Dell!)  Take a meter and set it to DC volts.  There will be a pair of test leads with pointed ends to poke at things.

You will push the points into the connector until it connects to the metal of the connector sleeve.  Connect the common lead to a black wire's connector.  Test all the colored wires with the positive (usually red) meter probe. Here are the correct voltages for a PC:

Yellow          +12 Volts
Red             +5  Volts
Purple          +5  Volts
Orange          +3.3Volts
Green           don't test; this turns on the PC when shorted to black
White           -5  Volts
Blue            -12 Volts
Gray    I think this one is for the power-is-on LED
Brown   Not sure about this one

The important thing is that the voltages are nearly correct when the computer is powered on because that shows the power supply to be good when under a load.

One other thing - sometimes a part can acquire a static charge which won't dissipate properly.  The only remedy for this is to wait until it discharges (unless you are a motherboard repair person).

Things that have hurt my equipment is usually near lightning strikes. Lost one treasured Mac to a lightning strike that hit the phone lines. Took out phones for three stories above me.  Mac did not fail right away but eventually lost it  (sniff :( ).   Lightning strikes across the strike have taken out a couple ethernet ports over the years even though my equipment has always been on a UPS.  Strong strike will generate an EMP which is sometimes picked up by a network wire of a resonant length.  Usually, though, it's not serious but if the storm is bad, we'll turn off the electronics until it's past.

I apologize for the length of this, but you get the idea of the lengths I go to fix things.

Best of Luck and let me know how it turns out if you have the time,
As always, take care.
Jon











On 09/17/2014 06:27 PM, Michael Havens wrote:
first certain keys sometimes don't work unless I hold the key down and
then after a time the character will appear (sometimes multiple times).
So it was recomended I pop the keys off and clean under them. So I do
and it doesn't fix the problem. No problem. I'll stick it under my table
and attach wireless periphiels too it. Then I need to go visit my kids.
So I figure I'll suffer with the keyboard problem. The day I left for
Miami (at the airport) the hardware internet switch would not turn on.
Then, after I arrive in Miami, I turn on the computer and a notice
appears at boot saying that 'the cooling fan is not operating properly'.
What problem do you think is causing this? I called my dad and he said
it sounds like the hard disk is going bad. He also said maybe the
keyboard controller (because of the internet switch).
:-)~MIKE~(-:


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