Dell inspiron 531 does not power up?

Are the lights on the keyboard still working when you hit caps/num lock?

Is this a laptop? Have you replaced the battery, ever?

Not a good sign but not all hope is lost. First clean and re-seat all of your main connections: Power supply, ram, CPU… Recheck. If you have another pc you can try swapping the power supply if you don’t have any success with cleaning and re-seating everything. PC power supplies are cheaply made and can die without warning. I’ll be honest it’s probably either your power supply, motherboard, ram or CPU in that order. If you have a video card that could potentially cause problems also.

I’m with @ARE_you_kidding_me, it sounds likes connections may need to be pulled apart and reconnected. Hope it is not the power supply that is on its last legs.
The other thing is to “dust” the area around the louvers and power supply, it may be overheating.

I’m in agreement. Take off a side panel and see what is going on in there. It could be so clogged with dust the fans won’t spin so it is overheating. That actually happened to my moms computer and a toothbrush and a can of compressed air fixed her up.

If you are getting some lights the power supply could be fine. Does anything ever get displayed on the monitor when you try to boot? Maybe a cat bumped the monitor cord, again, happened to my mom.

Check whether the PSU is working fine.

No beep = no POST. Most repairable errors at least get to POST and flash an error message. If you can’t even get that far, then there is something majorly wrong; something beyond a loose connection. Even a blocked fan will get you a beep before going into thermal shutdown.

I suspect you blew a capacitor on your motherboard, as that often happens to old rigs built for low cost. Then again, old, cheap PSUs like Dell often uses tend to fry themselves after a while; I’ve burnt a few. All that green light means is that power is going in, not that it’s actually working.

Regardless, a PC of that age and those quaint specs is cheaper to replace with something five times as fast/powerful than to repair, so I’d just remove the hard drive, get something better for $200–500, and plug in your old drive to get your old data back.

@johnpowell I’ve had that too thanks to my fuzzy little wanderers, but in those cases, everything works except the monitor; I get POST beep(s), hard drive lights, and everything. As for overheating, when I’ve mismounted heat sinks and/or forgot to plug in fans, even then the computer stays on long enough to give a beep or several before clicking off. Maybe our experiences differ though….

@jerv He does get it to turn on briefly and does not get a beep which actually can mean that the power on self test ran but failed. Corroded/loose connections especially with the CPU and RAM are still not uncommon. It never hurts to try, especially if the case has been kicked around any. I’m with you though almost everytime this happens either the power supply or motherboard is in need of being replaced. That’s usually when I end up replacing the guts in my PC (about every 5–7 years….)

@ARE_you_kidding_me My experience is that POST failures beep; one short beep for ‘pass’ and some other pattern for ‘fail’.However, it’s possible that the OP is having issues beyond my experience, which includes fried components, unseated DIMMs, a variety of loose connections, and the occasional clump of cat hair stuck to a film of nicotine and tar. Like my cars, I weigh the cost (both money and time/effort) of repair versus replacement ..though I’ve also done some interesting kludges to resurrect a “dead” rig, like using separate PSUs for my motherboard and drives or cutting up a swim fin to replace a bad thermostat gasket.
I’m not optimistic about this one though. While there is a chance that simply reseating things might work, I’m just not getting the warm fuzzies here. Just a hunch.

I’m not either without the beep but brief power on either post is not happening at all or it shuts the machine instantly down to prevent further damage. The fact that it does shut down probably means that it’s either being shut down by the post or the power supply is bad.