No signal to monitors/power to keyboard

[BepisOverdose]

Hi, recently i took the heatsink + fan off the cpu to give it a clean, once replaced, i can no longer get my monitors (tried a few including tv) to connect, power is definitely on the monitors
Keyboards don't seem to want to work either (in any port, which the mouse works in)

I've tried reconnecting each cable, even wen't as far as testing another motherboard and cpu, reinserting CMOS Battery, reseating graphics card, different monitors, cables (connected via card not motherboard) different keyboards (what makes me confused is the fact that the keyboard doesn't work in any ports, while mouse does, although the keyboard is not powering (led keys as indication), clicking lock keys(num, caps,etc.), their status lights faintly flash.

I cannot seem to solve my issue, any ideas?

Setup is:
https://support.hp.com/au-en/document/c04448312
modified with:
550 Watt Casecom Power Supply PN CC-550W-12CM
ASUS GTX1050Ti 4GB Expedition OC Video Card PN EX-GTX1050TI-O4G

I have removed GPU and ran the monitors from the on MB display ports, still nothing

[MKazi]

@BepisOverdose

Thanks for reaching out to us on HP Support Forums. I came across your post and would like to help. 

I understand that you have an HP Pavilion 500-404a Desktop PC and after cleaning it by removing the heatsink and placing them back in, the PC no longer works, I have read your post comprehensively. Fabulous analysis. Spectacular diagnosis of the issue before posting. Kudos to you for that. I appreciate the steps you have performed and have certainly done a good job.

I read that the keyboard does not work, but the mouse works in the same USB ports. Do you mean to say that the laser led light beneath the mouse is on?

If the PC is receiving power and is not booting up then the evidence points towards a hardware issue. I recommend you to perform the following steps to isolate the issue and arrive at a fix: 

NOTE: PLease skip the steps that you have already attempted. 

• Press and hold the power button on the PC for it to power off.
• Disconnect the power cable from the PC and also disconnect all other devices and cables.
• Now, press and hold the power button on the PC for 10 seconds and then release it.
• Reconnect only the mouse, keyboard monitor and the power cable to the PC.
• Power on the PC.

In case the issue persists then please review the steps from the HP no power/no boot troubleshooter guide. 

Finally, if the PC still does not work then I suggest you to reach out to our HP phone support team to check the available service options for your PC.

Hope this information helps. Keep me posted. All the best! 🙂

[BepisOverdose]

Thanks for your response MKazi,

Turns out 2 motherboards had 1-4 bent pins in the CPU socket (what luck i have), perhaps these have disabled the handling of keyboards and monitors, a third motherboard with an untouched CPU has provided the ability to use the computer once again.

with the keyboard and mouse, both are backlit so all is good when they light up, the mouse was lit up, the keyboard wasn't.

anyway, my problem has been solved.

Thank you.

[MKazi]

@BepisOverdose

You're welcome. 🙂

Your observation is very good. I'm glad you were able to figure it out. 

It was an honor to share this platform with you. Cheers! 

[SuurKoll]

Hello! I wanted to know,  did you change your power supply and graphics card and thats all? Does it work properly? Cus I have the same exact PC and I don't want to buy a new pc, so I think upgrading it is much better. If you still use this site, please answer 🙂