I suspect the PSU also, pacman1_63Why?Because the two leading causes of desktop computer failure, is;1) The computer is dirty inside2) Power Supply failure[Which stands to reason Pacman1,The PSU inside her desktop is a Switched-Mode Power Supply.Uses Heatsinks, and a small internal fan,
http://en.wikipedia.org/wiki/File:ATX_power_supply_interior-1000px_transparent.pngIn-between the Input Stage capacitors designated by the letter B, and the transformer C, is a Heatsink.Looks like silvery finned blocks stacked on a long flat rod.Essentially that's what it is. Aluminum rectangles composed of aluminum fins, and mounted to a flat aluminum bar.Seen again in-between the transformer C, and the Choke Coil D.Once 'gunk' has clogged in-between the fins, and around the fins, the cooling capacity drops tremendously. The fins cannot radiate the heat away.When the fan's blades, center hub, and surrounding shroud are clogged, it's cooling capacity drops tremendously also. (The air flow from the fan helps carry heat away from the fins of the Heatsink/s.When the computer calls for power, the PSU has to keep up. When dirt, dust, hair, lint, you name it, has clogged the cooling components, the cooling capacity drops tremendously.Heat = Wasted EnergyThe Power Supply tries to keep up with the call for power, but eventually cannot as components inside fail ]Also, see the LED's that are lit up, and the fan spinning? Means nothing.A) If ALL of the LED's were on at once, they would use less than 1 Watt of power.B) EACH fan uses 2 to 3 Watts of power.C) A typical Processor can use from 51 to 125 Watts of power. Just depends on what Processor it is.HP Pavilion Slimline s3620f desktop computer?Uses an Intel Pentium Dual Core E5200,
http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01527426&cc=us&dlc=en&lc=en&jumpid=reg_R1002_USEN#N156http://en.wikipedia.org/wiki/List_of_Intel_Pentium_Dual-Core_microprocessors#.22Wolfdale-3M.22_.2845_nm.29Can use up to 65 Watts of power. (TDP = 65W. TDP stands for Thermal Design Point)Primer:You push the Power On button.The plastic assembly of the Power On button in turn, presses against a Power On switch located inside it. (Example of an ATX Power On switch that is used in a LOT of Desktop PC's,
http://www.directron.com/atxswitch.html )Primer:The Power On switch is a Momentary Contact Switch.Pressing it briefly closes a circuit.The Soft Power On circuit.(Abbreviated as PS_ON)When the PSU is plugged into power, there is a constant 5 Volts (DC) present.The 5 Volt Standby power.Closing the Power On switch redirects the 5 Volts, 'excites' the Power Supply, and turns it on.(Sounds like a steamy novel, huh?)The first chipset to receive power is the BIOS chipset.The Basic Input/Output System program is initialized.BIOS looks to see what devices are connected, does a Ram Memory count, TURNS the Processor on, and hands the computer over to the Operating System.(Windows XP and Windows 7 are two examples of an O/S)You have a PSU with a weak voltage power rail.How to test it? Easy. Have a multimeter?(An economical multimeter can be purchased for as little as $5 to $12. Available in a multitude of stores. An auto parts store is but one example. Analog or digital is fine)The PSU for the Pavilion s3620f is a special shape. Same old PSU as the ATX form factor style, but different case shape, and size.A)
http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01358060&tmp_task=setupCategory&cc=us&dlc=en&lang=en&lc=en&product=3794733B) It's a 160 Watt unit, also,
http://www.cputopia.com/psu-replacement-hp-s3620f.htmlThe main power cable is a 24-pin ATX main power cable,
http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain24MINI, or not.There are 3 Main voltages you need to check for;A) 3.3 VoltB) 5 VoltC) 12 VoltWith the Mini ATX 24-pin power cable plugged into the motherboard, as shown in the photo to the far right of the Playtool link;The Orange wires are 3.3 VoltsRed wires are 5 VoltsYellow wires are 12 Volts.Power Supply unplugged from power, Anti-Static Precautions -> FOLLOWED, use two straightened out paperclips.One goes down into a socket hole with a Power wire, the other one goes down into a socket hole with a Ground wire.ALL BLACK WIRES are Ground wires.Using the 3.3 Volt power rail for an example.A straightened out paperclip goes down into a socket hole, with an Orange wire in it.Goes down into the socket hole, at the BACK of the power cable's connector. The back is where the wires are going in.It goes down into the socket hole, RIGHT NEXT TO the existing wire.Slides down past the insulation, AND touches a metal terminal at the bottom.(Looking at the middle photo of the Playtool link, you can see the tips of the round metal terminals, in the square socket holes )Leave it sticking up out of the socket hole.Now place a straightened out paperclip, in ANY socket hole with a Black wire in it. ALL Black wires are Ground wires.Multimeter function knob set to DC Voltage, the Positive probe lead (Red), is touched to the paperclip in the Orange wire socket hole.(If just a symbol for DC Voltage, it is the dotted line over the solid line)The Negative (Black) probe lead is touched to the paperclip in the Black wire socket hole.Plug the PSU into power. Turn the computer on.Touch your two multimeter probe leads to the paperclips.You should be reading VERY close to 3.3 Volts.Same thing for testing the 5 Volt power rail.Paperclip in a socket hole with a Red wire in it. Other paperclip is still in the socket hole with a Black wire in it.Again, same thing for 12 Volt Power rail. Paperclip in a socket hole with a Yellow wire in it. Paperclip is still in socket hole with Black wire in it.[Dangerous voltages are contained in the metal case of the Power Supply. AC voltage that may be from 100 Volts AC, to 240 Volts AC. Depends on what country you live in.The Power Supply is a converter. It converts the dangerous high AC voltage into three low DC Voltages. 3.3V, 5V, and 12V.In comparison two D cell flashlight batteries store 3 Volts DC ]For additional questions please post in a Comment.Regards,joecoolvette