PC wont boot

[jphegers]

I need some information from PC experts, I have a spare computer that has not been used for some time and wanted to connect it to my television to use as a media center but when turning on the power it turns on for 10 seconds then switches off and then back on after 3 seconds and continues doing that and won't boot up.
Is it an expensive problem to fix and should I rather look for another PC to buy?
I am technically handicapped and don't know anything regarding the inner workings of a computer

 

[WAslayer]

Costs to repair will depend on if any one component is broken or not and the cost to replace said component..

First step though, if you are handy enough, carefully remove all components from the PC.. take pictures of everything before you remove it, so you know where what goes when you put it all back together..

You will remove all cables, RAM, the graphics card and hard drives.. when you put it all back together, leave the hard drives unplugged, leave the graphics card unplugged and all RAM sticks..

Try boot again.. you should hear beeping.. if you don't, likely CPU or motherboard that's broken..

If you hear beeping, proceed to plug one stick of RAM back in and boot.. remember to connect monitor to onboard graphics port..

Try boot again..

 

[PPLdude]

Have you tried turning it off and on again

 

[Düber]

Change the motherboard clock battery with a new one, some boards don't boot if it is flat.

 

[jphegers]

Have you tried turning it off and on again

Yes turned it on and off a few times

 

[The_Traveller]

PSU ? Ask around many will borrow or even give you one to try out.