Strange Boot issue

[angeloemmetaly]

Hi everyone,
I have a very strange issue with my MacBook.
when starting the computer:

Blank screen, no startup tone, white light steady. I try basically everything from taking battery out for 30secod to PRAM... But nothing. Every time though after leaving the computer switched off for one or more days, ends with the computer starting. But lately this is happening very often so I would like to understand why this is happening. I already sent the computer for assistance one year ago and they changed the motherboard, but looks like this is still haooening now.
Some advice would be gratefully appreciate it many thanks

 

[MyMac8MyPC]

I would make a backup ASAP just in case the hard drive is starting to go bad. You should have a backup anyway.

 

[harryb2448]

Helps if you share with us model and operating system etc.

Assuming you are using OS X.7 or later, when you get t up and going reboot into Recovery Mode and run Repair Disk in Utilities. Who repaired it a year ago?

 

[angeloemmetaly]

Helps if you share with us model and operating system etc.

Assuming you are using OS X.7 or later, when you get t up and going reboot into Recovery Mode and run Repair Disk in Utilities. Who repaired it a year ago?

Is a 10.8 but my MacBook is a 17" pro form 2008. I bought it from this company who assembled it and upgraded to the latest ( at the time) operating system, 4gb of RAM, 2.4 ghz of CPU and 750 GB of Internal HD. The problem is that having a look at the activity monitor it appears that without running any application the user system is using already 80% of the CPU. A friend of mine told me that it could be possible that the 10.8 being a very heavy operating system is causing the logic board to overheat, considering this is quite an old computer. I don't really know if this is true or not but I already had my logic board changed around .1 year and ald ago and now I have the same issue, so definitely sow thing is causing my logic board to fail, the problem is that I don't know what I will definitely try the disk repair thing, thanks!

 

[chscag]

Don't spend any more money or time on that machine. The GPU has likely failed again (your motherboard had to be changed previously probably for the same reason) and may require the logic board | motherboard to be changed out again. Save your money for a new machine. Sell that one for parts on eBay.