Reboot

Hallo friends

I have a Imac OSX 10.8
Since a few weeks my iMac reboots spontaneous. I am at that moment surfing on the web. The Imac freezes for a moment and then it reboots.

After the reboot the pc works good. I did run all the test program's , they all say the system is OK.

What is wrong?

Thanks!!

HH

If I have understood your question correctly, your solution may be a matter of adjusting your settings.

Go to System Preferences>Energy Saver. Uncheck the box which says " Restart automatically if the computer freezes"

As an extra, you may wish to uncheck the box which automatically restarts the computer after a power failure.

Please let us know if (a) I have understood the question and (b) whether the above suggestion solves it.

Ian

Hallo Ian

The box is already unchecked

Well, that's one idea gone to the wall. Sorry.

Perhaps our senior colleagues could chime in with ideas.

Ian

Hallo Ian,

Thank you very much for your support.
I hope to hear from our senior colleagues

Regards

HH

hansheeresma said:

Hallo friends

I have a Imac OSX 10.8
Since a few weeks my iMac reboots spontaneous. I am at that moment surfing on the web. The Imac freezes for a moment and then it reboots.

After the reboot the pc works good. I did run all the test program's , they all say the system is OK.

Click to expand...

It sounds like you may have some bad memory. The symptom you described is typical when a memory error occurs. Other things can cause the same symptom but I recommend checking the memory first.

Download the free MemTest for Mac program and run it in extended mode. Post the results for us to take a look at. Here is the download LINK.

It looks ok??

Mac OS X 10.8.2 (12C60) running in multiuser mode
Memory Page Size: 4096
System has 2 Intel core(s) with SSE
Requested memory: 1811MB (1899102208 bytes)
Available memory: 1811MB (1899102208 bytes)
Allocated memory: 1811MB (1899102208 bytes) at local address 0x0000000101000000
Attempting memory lock... locked successfully
Partitioning memory into 2 comparison buffers...
Buffer A: 905MB (949551104 bytes) starts at local address 0x0000000101000000
Buffer B: 905MB (949551104 bytes) starts at local address 0x0000000139990000

Running 2 test sequences... (CTRL-C to quit)

Test sequence 1 of 2:

Running tests on full 1811MB region...
Stuck Address : ok
Linear PRN : ok
Running comparison tests using 905MB buffers...
Random Value : ok
Compare XOR : ok
Compare SUB : ok
Compare MUL : ok
Compare DIV : ok
Compare OR : ok
Compare AND : ok
Sequential Increment: ok
Solid Bits : ok
Block Sequential : ok
Checkerboard : ok
Bit Spread : ok
Bit Flip : ok
Walking Ones : ok
Walking Zeroes : ok

Test sequence 2 of 2:

Running tests on full 1811MB region...
Stuck Address : ok
Linear PRN : ok
Running comparison tests using 905MB buffers...
Random Value : ok
Compare XOR : ok
Compare SUB : ok
Compare MUL : ok
Compare DIV : ok
Compare OR : ok
Compare AND : ok
Sequential Increment: ok
Solid Bits : ok
Block Sequential : ok
Checkerboard : ok
Bit Spread : ok
Bit Flip : ok
Walking Ones : ok
Walking Zeroes : ok

All tests passed! Execution time: 3425 seconds.

The memory does check good. Next, run the Apple Hardware Test to see if it picks anything up. LINK

Hallo,

I did run all the tests, including the long one. There where no problems found.
There must be some report on my iMac, after the crash.

If you can find it, post the crash report. We'll take a look at it to see if it tells us anything. Sudden freeze ups and restarts are almost always caused by defective hardware. The most common is bad memory but your memory checks OK. The machine may also have a bad power supply which can cause rebooting, but there are other causes also. This is one of the most difficult things to chase down and resolve. Apple replaces the entire logic board when this occurs and the machine is brought into them for repair. But that can be very expensive.

Hallo,

Thanks a lot. I think I must live with it.
We have tried everything. So, case closed!