Are you sure that it goes to the sleep mode? Or simply turning off?
Please try the below instructions too.
1. Go to Start, type power options in the Start Search box and then press ENTER.
2. Click "Change plan settings".
3. Click "Change advanced power settings".
4. In the popup window, expand "Sleep".
5. Change "Allow hybrid sleep" to "Off".
6. Click OK.
If the issue still persists, please run power efficiency diagnosis by following the instructions in the link below and let me know if you get any errors.
Also, try updating the computer's video driver and check if the issue persists. GO to the link below, select your operating system (E.g. Windows 7, 64 bit), then click next. Select Driver - Original and under that, click Original Intel Graphics Driver. Then click Download. Download and install the driver.
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