Lumia 930 Windows 10 screen blank when making a call.

[Dagwood1984]

Windows 10 on my friends Nokia Lumia 930 seems to have a glitch. I just bought him this phone second hand as a gift for him. My wife and I both have the very same phone, but unlike my friends, we are still using Windows 8 which seems to work fine.
Okay the glitch is:
Making a call very often triggers the screen to go blank/black. Simply touching the on/off central button does nothing to trigger the screen back into life. With the screen effectively switched off, it's not possible to end the call, or do anything else for that matter. Sometimes this cannot be altered and becomes a damned problem. Pressing and holding the central button will trigger switch off, which isn't particularly useful, although it becomes the only option. The button hardware isn't the issue as it works fine in other circumstances.
Is this a known W10 problem?
Has anyone else suffered this issue and if so, how can I resolve the problem for my friend. I am holding off from updating my own phone to W10 as a result.

 

[madhi]

This is a known issue for 930. The proximity sensor isn't working well b'cos of the screen moving forward. Just press the upper right corner of the screen and the display will be back.
If it's still under warranty, get it repaired. It's a hardware issue.

 

[Dagwood1984]

Hi Madhi,
Thanks for your feedback/comment. Obviously the next step is trying your temporary fix with judicious application of pressure on the screen corner. If that works the magic, then a repair is in order. Do you have any experience of reliable and knowledgeable repairers? I thought perhaps The Geek Squad? But don't have experience to back that up.
Thanks Dagwood.
*Update.
Tried the suggested fault finding and your suggestion worked. Next step warranty repair. Thanks again Madhi ��