|You may have a poor connection inside your computer case somewhere.|
Unplug the case/power supply.
Power off your monitor.
Open up the case by removing the left panel as seen when you're looking at the front of the case.
Check all the connections of the wiring to make sure they are all the way onto their pins and into their sockets, especially the main connector from the power supply. The wires close to the mboard going into the main power connector/socket should be more or less perpendicular to the mboard surface rather than at an angle. Make sure all cards in slots are all the way down in their slots.
While you're in there, if the cpu fan/heatsink has mung (dust, lint, etc.) on it, clean it off, but DO NOT use a vaccuum cleaner to do that (they produce a tremendous amount of static electricity when running, and anything connected to them can discharge that to your components) - use canned air, or an air nozzle if you have access to an air compressor, or an artist's brush that can be used in small spaces, etc. It may be difficult to clean the top of the heatsink under the cpu fan - the most likely place to have mung on it - and the bottom side of the cpu fan blades unless you remove the fan. If you have a case fan, clean that too if it needs it.
With the cover still off, restore the AC power, start the computer and make sure the cpu fan spins - if it doesn't spin don't use the computer until you have replaced it.
If it spins too slowly, and/or if it makes rattling or screeching noises, most likely to be noticed when the computer has cooled to room temp, has not been used for a while, and then is started up, the cpu fan's bearings are failing - replace it as soon as you can.
See response 2 in this - try cleaning the contacts on the ram modules, and making sure the modules are properly seated:
Usually if you have a power supply problem the cpu fan either works or it doesn't, but you could ...
Check your PS.
See response 4 in this:
There is no info about your exact model on the HP site, and what SR5060 models there are listed have no info about the power supply used in the system. If you need to replace it, find the Compaq/HP part number on it on a label - xxxxxx-xxx - and quote it here in this topic.
Usually you can replace it with any standard sized standard ATX PS.
Standard (PS/2) power supply size - 86mm high, 150mm wide, 140mm deep, or 3 3/8" h x 5 7/8" w x 5 1/2" d , or very close to that, though the depth can be more or less for some PSs.
Don't buy an el-cheapo PS.
See response 3 in this:
Those SR5060A* models have an Athlon mboard and use 64X2 cpus.
Apparently your SR 5060 il model has
Intel Core2duo 1.8ghz
Intel 945G chipset
Those SR5060A* models have a PCI-E video card in a slot.
If your mboard does too, the original power supply capacity is adequate, but if you have changed which video card it has in it, or if you want to be able to install a better PCI-E card in the future...
Your power supply must have at least the minumum capacity required to support a system with the graphics card you are using installed, or the max graphics card you might install in the future.
(Onboard video - video built into the mboard - IS NOT A CARD!)
You can go to the video card maker's web site and look up the specs for the model - often under system requirements - the minimum PS wattage, and, more important, the minimum amperage the PS must supply at 12v is stated. If you don't find that, any card with the same video chipset including any letters after the model number has very similar minimum PS requirements.
If you want to cover any possible video card, a minimum 600 ot 650 watt power supply will handle any current high end video card, or even a X2 card (two video chipsets on one card) or two cards in two slots.
"sometimes my cpu starts by itself when i switch on my ups but not the computer power button.is this a problem with my power supply unit"
Not necessarily; probably not.
Sometimes just the electrical "noise" created when you switch on the power to a UPS or a power bar or an anti-surge power bar you have the computer plugged into will cause the computer to start up.
I have an anti-surge power bar switch that sometimes causes that, but it only does it with one of the two computers I have connected to that power bar.