I purchased a custom built computer which as of today would switch on when I press the power button but after 5-8 seconds would turn itself off and then it would again turn on by itself after 5-8 seconds and repeat the cycle. I can't get to the BIOS setup or anything as my monitor does not get signal from the computer.
I could be wrong, but it sounds like a faulty PSU to me.
When I built my own PC I ended up having a similar issue. The system worked well for a while, but started to restart a few seconds after I turned it on, and then cycling on and off until I cut off the power. I eventually found out that the PSU was faulty and after returning and replacing the old model, the system was good to go.
After looking at the link you provided for the full specs, it seems that your system has an 800W PSU, but there's no mention of what brand it is. The difference between a generic no-name PSU and a Corsair or Seasonic model is huge in terms of reliability.. and they don't really provide any details on what you're getting.
How long has it been since you bought the system? If the warranty's still valid, I'd suggest having it sent back for repairs at Envizage's expense.
If not, I'd suggest opening up the side panel of your system and looking for a sticker somewhere on the PSU to indicate the brand, etc, and letting us know what you've currently got in the system.
It's an Evo labs power supply. I can get a free repair, the only problem is it will take a week or so overall for it being picked up, then fixed and sent back so I wanted to see if I could fix it myself first.
I got the PC on the 16th of July so it hasn't even been a month yet.
Well.. I'd never heard of Evo Labs until now. Someone can correct me if I'm wrong, but it sounds like a generic value-brand PSU that I can only find distributed through Envizage.
This seems to agree with my either thought about it being the PSU. You COULD have the warranty replace it, but you'd probably just get another generic PSU, and it'd meaning waiting at least a week (but probably longer) before your system was running again.
Personally, I'd just go to the nearest computer store and pick up a new Corsair or Seasonic PSU. It'd cost, probably, around $100 for the kind of wattage your system would need, but it'd guarantee you'd have a reliable brand PSU in the future and would allow you to get your system fixed much faster than having it returned for the warranty would.
It's up to you whether the cost of a new PSU is worth the cost.. especially since the warranty on your system would cover a replacement if you had the patience to wait for it.
Random on and off restarts like this usually are representative of a bad power supply, but if the cpu isn't touching the heat-sink it can and will heat up almost instantly. I build so many systems that it becomes almost so routine, i inadvertently placed a heat-sink on in the wrong direction one time and it wasn't touching properly. My system did in fact react almost identically to what your describing, so I would take a look at that.
I managed to fix the problem! The entire time it was one of the RAM stick's which was the problem. I took one out and the computer worked, when I put it back in, it kept turning off and on again.
I'll just get another 4 GB RAM stick to get 8GB RAM again.
I should probably mention that I had believed the same thing when I was troubleshooting my own system. It initially started working again when I took out a RAM module, and I thought the problem was solved. But after a while, it started to fail to boot again as the PSU continued to degenerate.
It might be worth checking each stick in every possible combination of slots on your motherboard before committing to buying new RAM. Confirm that the RAM in question is actually bad by trying it (alone) in each of the RAM slots. Then test the other (working) RAM in each slot.
I initially did the same sort of troubleshooting on mine and the PSU continued to degenerate to the point that it wouldn't post at all, even with three of the four modules removed. It seemed like it was bad RAM at first, but later it became obvious that the PSU was completely dead and had to be replaced.
What I did was I took out one of the ram sticks and it started working, put it back in and we were back to square one, I then switched the two rams and it didn't work. I took out the bad one and put the good one in the slot which the bad one was in, worked fine, just slower to log in at windows screen.
I've had a similar issue with a faulty motherboard...it may not be the PSU. Best bet is to return it, get the system builder to fix it, then replace the generic PSU once you have your system back up and running again.