What part might I have unintentionally touched?
What part might I have unintentionally touched?
I began by cleaning my PC and removing all the dust. Then I unscrewed the CPU fan to apply thermal paste (using an AMD Wraith). After that, the backplate fell, so I had to remove the motherboard to get it out. I connected the backplate with the AMD Wraith, reattached the motherboard, and after a few seconds, my PC started up. However, when connecting devices, the keyboard and mouse didn’t light up, the monitor showed no signal, and I couldn’t boot at all. What mistakes did I make?
Hello there, fresh member! It seems you'd benefit from getting familiar with the system's inner workings before diving in.
You might try repositioning all parts once more and observe the results. Also verify that every cable is properly connected. Still nothing? Test by transferring your parts into another PC (perhaps a friend's or family member's), one at a time, to check if it starts. This will help pinpoint any damaged components. If a part fails, it likely suffered from static discharge—avoid doing this again.
EDIT: During cleaning, avoid using dusters or cloths that could create static electricity and harm your components. Compressed air would be the best option.
Here's one method.
Some would tell you to do this on a table, completely outside the case.
Strip it down and then add components back, one at a time, to try and isolate the offending component.
Turn the power off and unplug the power cord.
Disconnect everything externally connected except the mouse and keyboard (printers, USB devices). If you are not using a wired mouse and keyboard see if you can borrow one.
Disconnect the power and data cables from all the drives inside the computer (Hard drives, DVD/CD drives).
Remove all the cards installed in the PCI slots including the video card, if any.
Remove all the RAM sticks.
Now connect the power cord and turn the PC on.
The motherboard should start beeping. You should get a beep code that tells you there is no memory. This is good, it means the processor is functioning and the motherboard is good so far.
Add one stick of memory in Slot A1 and power on. More beeping could mean “no video card" if your CPU does not have integrated video.
If your CPU does not have integrated video, add the video card and connect it to the monitor. You should get no beeping and you should see the BIOS screens, ending with the message that there is no boot device.
If you get no video, then change to another single RAM stick in the same slot and try to power on. If necessary, rotate the RAM sticks to other slots to confirm you don’t have a bad RAM slot.
Continue adding components one at a time.
If at any point the PC fails, the last component added was the problem one.
If you removed everything and there is only the motherboard (with integrated video), CPU, and power supply to contend with and it does not POST or show anything on the screen, then the problem is one of those three.
If you have tested by using another power supply, then it’s either bad CPU or bad motherboard. CPUs rarely fail, so motherboard is the most likely guess.
Try clearing the CMOS as a last ditch effort, and replace the motherboard battery. Both are long shots, but you don’t have much to lose at this point.
No, the CPU doesn’t need to beep; therefore, if it’s missing or faulty, it will still produce a beep (showing that the CPU isn’t essential for generating a beep code). Not every motherboard comes with beep codes—some have small LEDs that flash or individual lights that illuminate when there’s an issue. And your entire PC doesn’t have to be ruined; parts might still be functional if only the motherboard is affected, or vice versa if the components are the problem. The best approach is to test each part individually by moving them to another PC to pinpoint the defective one.