lenovo monitor blacking out irregularly

Have you a socket where you could plug in an external monitor (you need to identify if it's the display or the motherboard/graphics card that is causing the problem).

Not really, all the hardware is contained within the monitor case itself. It is an all-in-one PC. So there is no socket that would connect to another monitor

Check your power supply to the monitor, try another video card and video cable (HDMI, VGA)

Again, it's an all one table-top unit. There is one power cable in and no video out cables of any sort to check. The only bits that are separate are the mouse and keyboard. If you google 'Lenovo 10160 specs' and look at the images you can see that these are the only 3 components.

Does it have HDMI socket - you could connect to a TV?

I have connected it to the TV and the blacking out was mirrored on the TV screen. I know this means that it is probably the motherboard or graphics card, but I obviously don't want to go to the expense of buying new components. Also, I not sure that this type of PC is easily upgradable. I have scanned using the inbuilt Lenovo solution centre which says that there is no problem with the hardware. I was hoping that someone else had had the same problem and that the solution was just to give it a good shake!

An All-in-One is usually like a laptop. You can change only certain parts and only with the same type/model. All you can do is to open it see where the GPU is and see if you have any capacitors blown. If the GPU is on-board first teast RAM and if OK on test, MB is at fault. Usually if is the MB or PSU the PC gives a blue screen or restarts. You can also run a benchmark for GPU even if on-board.

Thank you for all the replies. I will open it up and have a poke around and see if I have any loose wires or such like. If I can't see anything obviously wrong I will probably just leave it as it is and put up with the random blackouts. After all it's more irritating than life threatening (he says with his fingers crossed).