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LED flashes 3 times

Hi

I have just tried to install 2 x 1GB chips into my G5 that already has 2 x 256mb and 2 x 1GB and the led on the front is flashing 3 times. I believe this means Incompatible memory installed.
So I then removed the new Ram and left the old Ram in the same place as before. Same thing happens, 3 flashes. I have been using the old Ram for 3+ years.
I have tried removing everything and just replacing the original 2 x 256mb and still 3 x flashes.
any ideas.

Peter

Powermac G5, Mac OS X (10.4.11)

Posted on Aug 6, 2008 10:43 AM

Reply
59 replies

Aug 7, 2008 10:12 PM in response to DaddyPaycheck

Hi

I have tried removing all the ram and giving the slots a good clean then reseating just a pair of chips
but still 3 flashes. It's probably the logic board because that's the most expensive bit and Im not very lucky.
If it's the Ram slot thats damaged then it's still a new board i guess. Might pop down a apple store for a professional opinion. Unable to reset PRAM and NVRAM does not do anything because the mac does not start to boot from the HD.

Thanks anyway.

Peter

Aug 7, 2008 12:19 AM in response to peter_luck

In some cases, when you change the RAM configuration
(and the RAM is OK) you may have to reset the PRAM
in order to get the new arrangement recognized again.

And in several instances, the RAM chips you use to
upgrade have to be matching chips. Same speed, etc.

Of course, some RAM chips have to fit snug and after
some time, they may have developed damage; and if
they had been handled by the contact edges, that can
affect their performance or shorten their life.

In a few cases, the RAM slots themselves may actually
start going bad; or there may be dust in the place where
the chips have to go, so they can't make a full connection.

There are several on-board trouble codes for the Tower Macs;
and I no longer have a link to the Support page showing them.

Good luck & happy computing! 🙂

Aug 7, 2008 3:17 AM in response to peter_luck

Hi peter_luck-

Try reinstalling the RAM. DO not forget that it often takes quite a bit of force in order to seat the RAM until you hear and feel it click.

A reset of the NVRAM after a change in RAM configurations is often helpful: Resetting your Mac's PRAM and NVRAM

The link to the page that helps to interpret LEDs is here: About the Power Mac G5 (Late 2005) diagnostic LEDs

Luck-

-DP

Aug 8, 2008 10:52 AM in response to DaddyPaycheck

Not all of it, and not all at once.

I have gone through extensive testing on this unit. I've switched out hard drives, video cards and RAM. The unit will run for a time after several attempts at starting it. Once I got it to start, I ran the Apple Hardware Test... I've done this twice (long and short) the testing passed everything. I've reset the SMU, reset the PRAM, and prayed......nothing helped.

From what I can see it's a bad Logic Board and it just happened, there were no signs of it going bad, it just went.

The three flashing lights are annoying to say the least. That really tells me nothing, since the RAM is not Bad.

Time to pull another 4 grand out of my pocket for a Mac upgrade. Or else by a Psystar Machine.......just kidding Apple, don't send the gestapo to my house.

Aug 21, 2008 6:33 PM in response to peter_luck

The act of heating the logic board at the point where these RAM sockets are
soldered on, and have that work, means there are micro-fractures or a faulty
solder joint at the junction - - or worse - - a component nearby has failed.

Since heat expands and the sections needing a proper connection would be
forced together tighter at the higher temperature, that situation could be an
easier fix than some others involving a logic board's complex circuits & parts.

Had you noticed anything odd prior to this apparent failure, such as slower
applications, or other sluggishness? If this issue had started going out be-
fore your AppleCare coverage expired, and you were unaware of the cause,
you could've had some recourse through AppleCare in this matter... About
all a person could do, is pay for the tech support call, and have your notes
ready; and ask what - if any - options you have, since the cost of this at a
retail repair rate, breaks the bank; when a repair costs so much you can't
continue to do your work, you could be bankrupt. You don't need a computer
to go broke; anyone can do that and be essentially computer illiterate!

••• ••• ••• •••

Good luck & happy computing! 🙂

Aug 24, 2008 8:33 AM in response to peter_luck

Hi Peter,



don't let the hair dryer continuously run. It will overheat your system and the fans want stop running.

What I do, before I start my PM G5, I open the side cover and take the processor fan out. Then I heat the logic board with a hair dryer for about 1 min in the area of the rams. But not too hot ( 40-45 °C). After this treatment I install the fan back and close the 2 cover again.

And normally the Mac will start without blinking and will work until I shut down again.

I think it has something to do with logic board, some bad connection/interruption where the rams are connected. But I could not find the source of this failure.
I guess the real apple specialist will know where the problem is, but they don't want tell us.
Its better to sell new machines.

Good Luck

Juergen

Aug 27, 2008 12:48 PM in response to peter_luck

For two weeks I have had this problem. I have removed my old RAM and installed new with no change. I actually had the computer start up a couple times. I let the flashing lights flash until the fans come on. Then a power off and power back on while pushing the power button three or four more times quickly. I got the start-up sounder and reset the PRam by holding CTRL OPTION R & P. I got a second sounder and the computer came up. Went to Disk Utilities and the system froze. Powered off manually and and back on. My computer came up a couple more times, froze, powered off manually and now won't start up. I am frustrated and mad as **** that my Mac is down. With all my RAM installed I have two by 1gig and 4 by 256mb. i have the original 160 gig HD and I added a 500 gig HD. I have also replaced the Optical drive with a faster unit. I have a HP Printer, an HP Scanner, and an HP Camera. My graphics card is the original and I have added a 4 port USB Card. Someone tell me there is a simple solution to this sudden Start-up problem!

Aug 27, 2008 4:31 PM in response to stukn69

Three flashes. I have the exact same problem with a Dual 2.0ghz. The first version Dual 2.0 is very prone to have logic board problems. I purchase a defective Dual 2.0 and sleuthed out the general location of defect. There are myriad and minute traces that can fracture when installing RAM (one has to apply lots of pressure the get the RAM to snap in the slots). Sometimes you will get a connection on startup, other times not. I applied pressure in a specific area and she booted right up. There is a component to the lower right of the upper RAM bank. The solder points form a square. Immediately to the left of this I applied pressure. This Mac has been running two weeks and when it crashes, I apply a little bit more pressure. I've installed a device and I have twice had to give quarter turns to a screw I mounted. Here's a pic of the device:http://www.davidroland.us/000_0439.JPG. It is heavily padded beneath the screw and I believe heat and distortion to the padding from the pressure is what caused me to readjust the pressure. This is a temporary fix until I find a new logic board of a newer version.

Sep 2, 2008 7:40 AM in response to peter_luck

I have spent many hours trying to get my G5 to function. The three flashing lights when powering up is dominant. I have been able to start up a couple times and I get 2.5 minutes of computing time before the screen freeses. Needless to say I am heart broken over this. I am currently on hold for Apple Support. I had thought Apple Support would review these posts and weigh in with a position. Wishfull thinking on my part. I'm afraid my future has $$$$ to fix the problem.

Steven

LED flashes 3 times

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