PC stopped working --> Replaced components --> is it still not functioning?
PC stopped working --> Replaced components --> is it still not functioning?
My computer unexpectedly stopped working the night after I powered it down. Before that, a storm knocked out the electricity, and when power returned I could still boot up and use it for the rest of the day.
The following morning I attempted to turn it on, but nothing happened—no sounds, no fan lights, just a completely unresponsive machine.
I performed several power cycles, switched to different power outlets, and eventually suspected that either the power supply unit or the motherboard was faulty. I replaced the PSU, MOBO, and thermal paste, reconnected everything with fresh cables, verified the CPU placement, and completed the assembly. After testing the new components, it functioned properly, but when I tried to power on the PC and press the power button, the issue remained unresolved—no lights or activation.
I inspected all connections again, reinserted the battery into the MOBO, and everything seemed to be in order. However, I’m still unsure what’s causing the problem and feel uncertain about the next steps.
Over the years, I've had two lightning strikes near my house. On both occasions, there was a very loud bang when lightning struck tall trees close by.
During the strikes, conducted surges into my house along AC mains wiring, coaxial cables and telephone lines, destroyed my broadband modem, hardware firewall, Ethernet switches, telphone answering machine and other small items.
by the time the lightning strikes had finished destroying three series-connected devices, one after the other, the energy levels had dissipated sufficiently and my computers survived. I was lucky. Other people in the neighbourhood had wiring blasted out of interior walls and glass TV screens cracked.
The most sensitive parts in a computer to overvoltage/current surges during a storm are the mobo, CPU, RAM and GPU. Many circuits operate at very low voltages, down below 1 Volt. The highest input is the nominal +12V EPS rail. Surges of hundreds or thousands of Volts result from lightning strikes.
To a certain extent, the ATX PSU is more robust, because it's designed to work on the vagaries of an AC mains supply, up to a nominal 240V (plus 6% and transients). However, the PSU is often the first item in the chain during a conducted lightning strike and can die suddenly too.
You've already changed your mobo and PSU, but it's possible the CPU and GPU have died too. I'm not discounting faulty RAM either, but if your Ryzen 3900 is still working, I'd expect some signs of life in the new mobo.
Obtain/buy a cheap Ryzen CPU (anything supported by your BIOS will do). Fit this CPU into the mobo and attach the cooler. The idea is to try a different CPU in your new mobo.
Test your RTX 3060 in another computer to see if it's OK. If you cannot do this, obtain another working GPU. Anything will do, e.g. an old GT 630, GT 710, GTX 1030, etc.
With a known working GPU and replacement CPU in the new mobo, remove the RAM and power on the system. If there are signs of life with the new CPU, your 3900 has died.
Fit the RAM and see if the system POSTs. If it looks good, run MemTest86+ from USB to check the RAM has survived intact.
You should now know which components have died.
I've installed industrial spec lightning surge arrestors in all my coaxial antenna leads and RJ45 surge arrestors in critical Ethernet cables. I now have fibre-to-the-premises broadband internet, so that's one less line of weakness, compared to ADSL or cable broadband.
My main system is powered from a 1500VA APC UPS to provide a modicum of protection against mains surges. The UPS will probably die in a big lightning strike, but better it fails than a number of expensive PCs. I still expect to lose equipment in the next big lightning strike near my house.
Do not expect a single cheap mains surge protector strip to provide 100% protection. It can cost thousands of dollars to install adequate lightning protection.
Of course, your system failure might have nothing to do with the storm. It could be nothing more than a coincidence.
I've already swapped out the CPU and RAM with new parts, but it still wouldn't power up. Then I realized the issue might be related to the circuit board that houses the power button. I had to connect a USB and press the restart button, which helped get it running. It seems the front panel circuit board is the problem.
If the switch or the cable is faulty, you might be able to take off the front panel and replace the entire cable assembly.
This front panel kit contains:
Power switch
Reset switch
HDD LED
Power LED
Alternatively, you can purchase the Power switch cable assembly separately. Check that the switch dimensions match your front panel before buying.
You can also buy the Power switch kit alone. Ensure the switch shape fits your panel before ordering.
If your front panel has a Reset switch, simply connect it to the motherboard's power ON pins. Many cases don’t include a Reset button, so it’s often not available.