I had the same problem and applied the following fix which has so far seemed to work. Basically the machine is overheating...big time. If left for a few hours the chip will cool sufficiently to allow the machine to boot but will suddenly shut down after about 1 minute. Then every attempt after will cause the machine to cycle booting every 10 seconds or so. Not even enough time for the post screen to appear.
You will need to order a tube of genuine Ceramique Arctic silver heat sink paste. There are many fakes from china so buy from a trusted UK seller!
Remove the back cover plate to access the heat sink and fan area over the main board. Observe the copper heat pipe over the processor and the two rubber bungee things stuck to it.
(Leave the machine for an hour or so to cool, place the machine upside down but with the lid open. Now power up and place you finger on the copper heat pipe between the two bungees. You will feel this area of the pipe getting extremely hot - too hot to touch - as the machine boots. it will probably not even finish loading windows before the thermal safety cut out kicks in shutting down the machine.) This step is not essential but will determine if the fault is overheating rather than a main board fault.
REMOVE THE POWER SUPPLY AND BATTERY
Remove the fan (3 screws)
Remove the 4 screws over the processor chip holding the heat sink in place
Remove the heat sink
Inspect the heat sink for dust between the fins. I use a soft brush to remove dust. It’s way cheaper than using cans of compressed air.
Now it is necessary to replace the thermal compound on the processor. You may want to remove the chip. Use a small jeweller’s screw driver to turn the lock to the open position. Don’t forget to note the orientation of the chip and don't forget to lock it back in place when finished.
Wipe away all trace of the existing compound. I tried this next step twice before I got it to work. Firstly I used some white thermal compound I got with an AMD chip and was left over. This did not work so I investigated a better alternative. I ordered a small tube of Ceramique by Arctic Silver off the internet for the second attempt. You must use this! It is about £3.50 a tube, more than the regular stuff but evidently with good reason!
I also applied some to the two temperature sensors to the left of the chip. Ceramique Arctic silver is much more viscous than regular thermal paste and is white, not sliver. It’s quite awkward to apply so don’t worry about making it look pretty. If you have not ever applied thermal paste before check out instructions on Google first.
Put everything back together, except the back plate.
As before leave the machine upside down and open it. Press the power button and as before place your finger on the area between the two bungees. Interestingly it will get almost as hot but hopefully not cut out. Strangely after about three minutes it will begin to cool and from now on run without overheating and cutting out.
I hope this will work for you just as well. I would strongly suggest removing the fan once a year and cleaning out any dust in between the heat fins, as this model clearly has over heating issues.
