Faulty RAM, it seems: http://support.apple.com/kb/HT2538
The solution to both of these situations is to first re-seat the memory and test the computer again. If the memory fails the POST test again, try memory that has been verified to work correctly on another system (i.e., "known-good") or order new memory ...
To test memory, run Apple Hardware Test, but it may pass anyway. Run the extended tests. The POST code indicates bad memory so I would be suspicious of it even if AHT indicates it passes.
Thanks for the leads. I had got a new RAM card for my Mac about 10 days ago. Perhaps it could be causing this problem. I have read your links which appear to be start-up tones; I do not get such tones on start-up but got it twice when I had put the Mac to sleep. I am in the process of contacting the Apple technician who has installed the RAM. Shall let you know the end result once I know of the matter.
Thanks again. Take care and have a grteat day!
The technician whom I contacted did not turn up and the problem appeared to have gone away, but it has resurfaced again:
Just a little while ago, the problem I had mentioned in this thread has recurred: my unattended to Mac going black and giving out an alarm: three beeps followed by a pause. The screen would not come active despite pressing any number of keys, the Mac would not shut down despite pressing the power button, and finally I had to shut off the power supply from the wall outlet.
FYI,I had been working with Seashore when this problem recurred. But I have been playing with Seashore since 2 days and there was no problem then.
Have re-contacted the technician who should come today.
what did the technician tell you? Since a few days I got quite similar results when I am shutting my mac down or put it to sleep (3 short beeps, black screen, only poweroff stops the alarm sound).
Start-up and working works as usual.
And my USB adapter both fail to recognize different devices.
I assume a logicboard problem since the RAM works perfectly.
I am a medical doctor and am not acquainted with computer diseases!
This problem has not yet gone away and the technician who came to attend seemed unsure of what could be the cause. He gave the RAM card which he felt would be the culprit and asked me to go to the shop where I had purchased it and ask for a replacement. The guys at the shop inserted the RAM onto their laptop [windows] and reported that it was working. They paid no heed to my complaint that the RAM does work. They held the view that it was due to a mismatch of this Ram with the other RAM cards in use. I did not have any knowledge about how to counter this contention of theirs and even do not know whether they are right or wrong in so stating.
I have to get back to the technician with what you opined: it could be due to a logicboard [BTW what's a logicboard] problem and hope things get sorted out. Shall let you know of how things will work out and also, please keep me posted of how you are negotiating this 'dangerous' problem.
... The guys at the shop inserted the RAM onto their laptop [windows] and reported that it was working.
This is meaningless. The only way to rule out incompatible memory is to substitute memory verified to work on a Mac.
Ok even if I am still to find out the reason for the beeps and other phenomena, the logic board (Explanation: core unit of your mac, or more detailed on http://en.wikipedia.org/wiki/Motherboard) remains my favourite guess. I will open the mac to see if something inside has melted or broken and if I cannot find the cause I will send it to a repair service.
I will keep you guys informed.
After sending the MBP to a repair service they told me that it was indeed a serious logic board issue that caused the problem. Unfortunately, no fixing is possible and the replacement of the Logic board costs (900 Euro), which is simply ridicuolous. So this is why I will stay away from Apple from now, since my MBP after 1.5 years is already garbage.
Thanks for taking this care for filling up this thread with this critical information. I wonder how frequent this type of affliction affects Apple computers. Guess it is few and far in between...otherwise there would have already been a great uproar over this matter as it is with the matter of iPhone's having videos in an upside manner.
I am fortunate enough to have taken a 3-year warantee for my Mac which is one year old now. I will have to insist my Apple technician to look up into this Logic board issue and replace the same.
Do you have with you any documentary evidence related to this Logic board problem...any written communication received from the service center you had approached? If yes, could you please mail it to me to my mail ID given under my profile? Such a communication will help me to interact better with the Apple technician in resolving this issue.