help please, Puter not starting

[wayne_havingfun]

Hi, just tried installing an external caddy hard drive, it wouldn't complete the installation so i went through the trouble-shoot.
I restarted my puter, unplugged then plugged in the device, then got told to restart to complete installation. (Strange I thought for a caddy drive)
Any way, won't restart, my fan comes on, internal light comes on, but then it won't go any further, no power on the monitor, (stays on stand-by), bios dosn't seem to kick in either.
If anyone can help i would be greatful. I am confident in delving inside if required. thanks for reading.

[nanosani]

Probably the hardware you installed recently is not working properly. Remove it and then see if your puter boots and the monitor displays comes on.

[wayne_havingfun]

I can't get into my computer, it has completly shut me out. It dosen't seem to boot, just starts the fan off, thanks for responding though.

[nanosani]

See if your power supply has not been overloaded .. remove all the accessories from your computer and try to boot the computer with only the motherboard and processor intact.. then keep adding the accessories step by step until you find the malfunctioning device..

[wayne_havingfun]

I think I've sorted something, I removed my secondary H/Drive and it started, then inserted the caddy drive inside, it says there is a problem with that drive. just gonna get rid i think, many thanks, for everything.