Hp SR1050NX tower will not turn on. Everything else.printer,monitor etc. lights go on I have tried using a different power plug. Fans don't move, light doesn't come on. There is a very slight buzzing sound coming from tower. It was working fine, then I unplugged it for a few days while away. Tried to turn it on and nothing.

Try a different monitor. If that works, your old monitor died and you need a new (or used) one.

what tower? model, the monitor has nothing to do with power and dead fans in the tower.
'Sounds, (and silent to) means the PLUS in the PC is dead.
all things can be repaired, that is what technicians do.
here is the chain of events, ! to get noise (fans)
power in the wall 120vac , usa
power to the PSU,
the power button goes to the MOBO, and standby power is there
now and pushing said button the MOBO commands the PSU on
if the PSU is happy (PWROK) thinks PSU IS safe the PSU tells the PC its ok, and power stays up.
and fans run.

so my guess bad PSU, its easy to test with anyf $10 voltmeter,
ask.

tower PSU, 101

http://pcdied.com/power.html

black screen , totally is here,
one page covers this.

http://pcdied.com/black-screen.html


test one do all Desktop fans run
if not the PSU is bad. 99% we can 1% if PSU is ok.

Psu or motherboard fault and use reginout

Try the fuse on the monitor power cord, and if this does not cure, you will have to get another monitor....pretty good prices on ebay!

i) usually an computer enter's into power saving mode if computer monitor is not receiving any singals from the computer tower, so it has nothing do withur computer monitor(computer monitor is working fine), there is some problem withur computer tower.

ii) now try  removing all the physical connections going to computer tower(back side), wall socket  and replace them ....., (to avoid loose connections) 

   now see whether ur computer is turning on and working properly so that your computer monitor receive singals ....

  let me know what is happening

Thanking you

M. Sridhar

i think you have a problem in you power supply sir try changing it or try separating your monitors source of power.

Try this troubleshooting guide it has worked for me in the past 99% of the time http://arstechnica.com/guides/tweaks/troubleshooting.ars

try a different video card. any type you can get your hands on, PCI is perferred.

Remove the power supply after everything is unplugged and take it to your nearest electronics store. They should have a tester there. This is probably the problem.