"Switched off at the mains" - Do you mean it's unplugged or that a power strip, surge protector, or the outlet, itself, is turned off?

When was last time you replaced motherboard battery?

Ron

I mean switced off at the wall outlet, no power to the PC at all. The PC is just over 2 years old and its the original battery.I have tested the voltage and its fine.

That's what I figured, but you're probably from across the pond so I wanted to be sure what you meant.

And that's why I asked about the battery. If it's supposed to be holding BIOS settings when there's zero power to the motherboard, any weakness there might cause the settings to scramble which could prevent it from booting.

What happens if you power off, but don't switch off at the mains, wait overnight, and then try to start up?

Assuming the battery is good, then you have to wonder about the PSU first...(cheaper than a motherboard!), but I make no promises...

Ron

Anything ever get figured out on this?  Went away for the weekend and my system is doing exactly what is described here.  I shut it down before I left, now it won't start.

OOPS! This posted but  my comments disappeared...

Anything ever get figured out on this?  Went away for the weekend and my system is doing exactly what is described here.  I shut it down before I left, now it won't start.

This is an old thread.

1. What PC model and version of Windows?
2. Do you see anything on the screen?
3. Hear any beeps?
4. What color is power button and is it steady or blinking?
5. etc

Agreed it is an old thread, however the description from the original poster matches the symptoms I'm seeing, and the original poster didn't post a resolution.  Glad to see you're still out there.

To your questions:

1. Inspiron 545/Windows 7

2. Nope - nothing on the screen

3. Nope - no deliberate sounds (although there is a tick, see below)

4. No color, although when it's pushed I believe it's amber briefly [it's behind my finger :) ]

5. Green light on power supply is on.  it flickers when the power button is pressed (coincides with fan tick and sound tick)

6. Fan 'ticks' or spins a partial turn then stops when power button is pressed.

7. Also when power button is pressed, there seems to be an attempt at generating sound when the power button is initially pressed.

8. Amber light on motherboard is on

Does this boil down to a power supply issue?  I haven't dealt with troubleshooting them very much.

Yes I did solve it, but I didn’t received a solution from the boards and all that Windows stuff is way off the mark, it’s a PSU problem. I fixed it myself by changing the PC power supply using a generic one bought on ebay. Still working fine.  I found my problem was temperature sensitive, try directing a fan heater or hair dryer at the PSU fan for 10 minutes to warm it up, you might find it will then start up. You can find my full response ( to myself!) on the Tom’s Hardware site.

Best Regards

@ Franklin L - I did suggest that martiantimeslip had a PSU problem and I'd say the same for you now that you've described the symptoms in more detail.

Make sure any replacement PSU has a 24-pin or 20-pin+4-pin  motherboard connector(s) and the appropriate number of outputs for however many hard and optical drives you have.  You can find Dell OEM PSU here, here, here, and here.

You didn't mention the form factor for your 545, so sure the PSU fits yor form factor, and -as always- ask if new/used/refurbished and about warranty. :emotion-5:

Nice!  As counter-intuitive as it sounded to me, the hair dryer did the trick (only needed about a minute to warm it up).  Now it's running and I'm off to buy a new PSU.

Thanks to you both!