|"the pc is very old"|
That's only relative.
"the Phoenix- Award BIOS "
Phoenix was a separate company from Award until I think the late 90's (1999 ?) , when they merged , so the computer can't be older that that.
"Product: Philips / Iqon"
A Philips Iqon what ?
Apparently it can be a laptop or a desktop computer.
Look for a label on the outside of the case.
There's probably more on the label.
E.g. when I searched using Philips Iqon, I got hits with:
Philips Iqon Tesco3, Qlever DE-6303, Qlever DE6410, Qovalis ED-670, etc., etc. .
The motherboard in brand name system computers is usually NOT made by the brand name - it's supplied to the brand name by some major mboard manufacturer, and merely has a brand name bios version on it .
The model, sometimes the make, of a mboard in a desktop system is usually printed on the mboard's surface in obvious larger characters, often between the slots.
Sometimes the brand name model is shown in the bios, or on a logo (graphical) screen while booting.
Do you see anything like that, that you could post here?
"I recently had to reset the bios because of a power failure."
A power failure event does NOT reset the bios, and you don't need to reset the bios after one.
However, a power failure event can damage your computer or anything connected to it, especially if it was caused by a lightning strike, on the power grid or near your location.
If your computer doesn't boot after the power has been restored, either something was damaged, or connections inside the computer case were made poor by the event.
If this is a desktop computer -
Unplug the case/power supply, or switch off the AC power to it otherwise.
Power off your monitor.
Open up the case - e.g. if it's a tower, by removing the left side 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.
In the case of a power failure event, it's a good idea to unplug each wiring connector one by one, and inspect the connector and whateever it plugs into for evidence of damage.
If you have IDE drives, be careful when you pull off the data cable connectors - if there is a plastic pull tab near the connector, pull on that - if not, pull on the middle of the cable, not the edge.
Remove the ram from it's slot(s), wipe off it's contacts on the bottom edge with a tissue or soft cloth, install it(them) again, make sure the notch(es) on the bottom of the module line up with the bump(s) in the slot(s), the latches at the ends of the slots should both easily latch and be against the end of the module(s) , and the module(s) is(are) all the way down in it's(their) slot(s).
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.
Also check for mung on the video card fan and heatsink if it has that, and the power supply's openings / fan.
With the cover still off, restore the AC power, start the computer and make sure the cpu fan spins - if it doesn't spin, if you're sure the power supply is working okay, 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 - the cpu is likely to overheat as a result of that if it can no longer spin it's full speed - replace it as soon as you can.
Try booting the computer.
If it still won't boot normally.....
- make sure the hard drive(s) is(are) spinning
- It is common to un-intentionally damage IDE data cables, especially while removing them - the 80 wire ones are more likely to be damaged. What usually happens is the cable is ripped at either edge and the wires there are either damaged or severed, often right at a connector or under it's cable clamp there, where it's hard to see - if a wire is severed but it's ends are touching, the connection is intermittent, rather than being reliable.
Another common thing is for the data cable to be separated from the connector contacts a bit after you have removed a cable - there should be no gap between the data cable and the connector - if there is press the cable against the connector to eliminate the gap.
80 wire data cables are also easily damaged at either edge if the cable is sharply creased at a fold in the cable.
Try another data cable if in doubt.
- look in your bios Setup for the current voltage readings. What is supposed to be +3.3v, +5v, and +12v must be within 10% of the nominal value - if any of those are not, you must replace the power supply. (If you have an AT computer, which I doubt, there will be no +3.3v reading in the bios.)
- look at the Boot Order settings or similar in the bios.
That should list floppy drive first (at the top) if you have one (it can be first even if you don't have one) , CD drive or similar second (or first if you have no floppy drive), hard drive next.
If you have more than one hard drive, there may be a listing there for each one. The drive you want to boot the operating system from must be at the top, of the hard drives listed.
If you have more than one hard drive, there may be a list of hard drives, often near the Boot Order or similar settings.
The hard drive you want to boot the operating system from must be at the top of the list.
If you have the hard drive you're booting from connected via a data cable to a drive controller card in a mboard slot, SCSI must be listed before all hard drives in the Boot Order or similar list.
Remember to Save bios settings if you made any changes.
Try your computer.
If it still won't boot normally, try connecting a different power supply that's from a working computer you have, or a friend has, if you can - they're frequently damaged by a power failure event..