Power light blinks but nothing else happens?

RAM. Pull every stick, seat one in the first slot, try booting. Swap sticks until you find the dead one. No luck at all? Check the board's diagnostic LEDs — whatever stays amber or red is your answer.

Dead CMOS battery — can it actually prevent booting?

On most modern boards, no. You just lose your clock and BIOS defaults on every power cycle. But I've seen Gigabyte and ASUS boards from the 2015-2018 era refuse POST entirely when the battery got too low. It's $3 and takes ten seconds to swap. If the machine's been sitting for months, just do it.

Turns on for one second then shuts off immediately?

Something is probably short-circuiting inside the case. Open it up and look around — stray screw sitting on the motherboard tray, cable resting against pins it shouldn't be touching, a brass standoff under a spot that has no mounting hole. Any of those will make the board cut power to protect itself. If the case looks clean, check your CPU cooler next. No thermal paste, or the mounting isn't tight, or the fan isn't plugged into the right header — the processor will hit thermal shutdown within literal seconds and the board kills everything.

Dead PSU? Fix it, always. $60 and you're done. Dead RAM? $25-50, no-brainer. Dead motherboard depends on age — compatible replacement boards for older CPUs can hit $200, and at that price a whole new platform is $300-400 but actually faster. Dead laptop motherboard is the worst deal in PC repair. Replacements cost $200-500 and at the high end you're halfway to a new laptop anyway.

What do I tell the repair shop?

What you were doing when it died. Whether there was a storm. What sounds it made — clicking, beeping, or total silence. Anything you changed recently. They bill diagnostic time hourly and every clue you give them is time they don't spend guessing, which means money you don't spend paying them to figure out the basics. Mention what you already tried.

Computer Won't Turn On? How to Fix It Fast

You press the power button and nothing happens. Or the fans spin for a second and cut out. Or it starts booting and crashes before Windows loads. All three feel the same at 11 PM when you’re staring at a dead machine, but they point at completely different hardware. What happens when you push the button tells you where to look.

Nothing at All, Not Even a Fan

The dumb answer is right more often than I’d like to admit. Plug a phone charger into the same outlet the computer is connected to. Phone doesn’t charge? The outlet is dead — tripped breaker, dead power strip, surge protector that sacrificed itself during a storm. I get at least one of these a week. A guy called us certain his motherboard fried. Already had a $400 replacement in his Amazon cart. His office outlet was on a breaker that tripped two nights earlier and nobody noticed. Cancelled the order.

If the outlet works: check the rocker switch on the back of a desktop PSU — the little I/O toggle people bump when fishing behind the desk. Check the power cable on both ends. Laptops — the charger brick has an LED. LED off means charger problem, not laptop problem. If the laptop was showing plugged in, not charging before it died, that’s probably the actual issue. LED on but laptop dead, try the capacitor drain: unplug everything, hold power for a full 30 seconds — actually count it out, most people let go at ten — then plug the charger back in and try again. Resets the power management controller. Works on maybe one in five dead laptops.

If none of that: PSU is suspect. If the computer was randomly shutting off before it stopped turning on entirely, the PSU was probably dying for a while. Open the case, pull the 24-pin connector off the motherboard, bend a paperclip into a U, stick one end in the green wire pin and the other in any black wire pin. Plug it in, switch on. Fan spins? PSU lives, problem is elsewhere. Fan stays still? Dead. Replacement runs $50-80 from Corsair or Seasonic. Skip the $25 Amazon specials — I’ve watched two cheap units fail and take the motherboard with them this year.

On a laptop there’s no paperclip test — if a known-good charger of the right wattage doesn’t work, you’re looking at the charging port itself. Barrel-plug laptops have a physical jack soldered to the board that wears out over time. First the plug needs wiggling, then it only works at one angle, then it stops entirely. Shop repair is $40-80.

Fans Spin But Nobody’s Home

Power is getting through. LEDs on, fans running, maybe the keyboard flashes. Screen stays black. The motherboard is crashing during POST — the self-test it runs before Windows even enters the picture — and something is failing before it can send a signal to the display.

Check the monitor. About 15% of “no display” tickets I handle turn out to be the monitor itself — wrong input, loose cable, dead panel. Swap the cable. Try a TV. If that specific symptom is your problem, the no-display guide goes deeper.

Then RAM. Pull every stick, seat one in the first slot, try booting. Works? Add the next. A client had a three-year-old HP desktop go black one morning — nothing had changed, she was already shopping for a replacement. Walked her through reseating the RAM over the phone. Booted on the first try. Thirty seconds.

If your CPU has integrated graphics — most Intel chips, AMD G-series — pull your dedicated GPU entirely and plug the monitor into the motherboard video output. Boots? Dead card. Some boards also have diagnostic LEDs near the top-right corner — four lights labeled CPU, DRAM, VGA, BOOT. Whichever stays lit after power-on is pointing at what failed.

Starts Then Dies

You see the manufacturer logo, maybe the Windows loading dots, then it freezes or blue screens or reboots itself.

Force-shutdown three times in a row — hold power until it dies, turn it on, repeat. Third time, Windows drops into recovery mode on its own. Try Startup Repair first, then System Restore, then Safe Mode. If the problem disappears in Safe Mode, something you installed recently broke things. If you’re getting a blue screen with a stop code, that code usually tells you exactly what failed.

Clicking sounds from the drive? Read/write head is dying. Back up everything immediately. That drive is not getting better.

Laptops Are Their Own Thing

USB-C chargers are the new confusion. Your laptop shipped with a 65W or 100W adapter for a reason. That 30W phone charger from the nightstand might blink the charging LED but it can’t actually start the machine. Check the wattage on both chargers.

Laptop doesn’t sit flat on the desk anymore? Trackpad feels stiff or unresponsive? Battery swelled. Lithium cells do this as they age and a swollen battery is a real fire hazard — not hypothetical. Stop charging it, stop using it. Replacement runs $50-100.

If you’ve tested the outlet, tried a known-good charger, done the 30-second drain, reseated RAM on a desktop, checked the monitor — and still nothing — you’re looking at a dead motherboard or CPU. That needs parts most people don’t own. We can do a WhatsApp video call and walk you through the physical tests live, or if the machine partially powers on, we connect remotely for the software side.