repairing an HP Z420

[Ferrous]

I have HP Z420 Workstation that on startup beeps six times as the power button flashes red. to my understanding this is a mother board failure how do I go about  repairing or more likely replacing the damaged component.
can I simply buy a replacement board from Ebay, or are newer alternative parts suggested?

I want to avoid as much tinkering as possible as I am not skilled in PC repair but I am also interested in upgrading the processor if at all possible.    

[erico]

Here is a link to the possible LED blink codes and the colors of the LED when blinking. 

https://support.hp.com/us-en/product/hp-z420-workstation/5225033/document/ish_1997210-1528385-16

Take a close look at the blinks you are seeing and post the result here in your thread.

You would probably be better served by letting a knowledgeable PC technician take a look at the error code issue. Before you do that, try resetting the BIOS if you feel that you can do that.

Reset the Complementary Metal Oxide Semiconductor (CMOS) data for your computer.

CAUTION:

This product contains components that can be damaged by electrostatic discharge (ESD). HP recommends using an anti-static wrist strap and working over a non-carpeted floor with a conductive foam pad to reduce the to reduce the chance of electrostatic discharge (ESD) damage.

1. Turn off your computer, and then disconnect the power cord and any cables from the computer.

2. Make sure that you have the model number for your computer, go to HP Customer Support, and then navigate to the product page for your computer.

3. Open the specifications document or service guide for system board information, and then find the steps for resetting the CMOS.

   The steps for resetting the CMOS might be named Clearing CMOS or similar.

   • If the guide lists steps to reset the CMOS: Follow the instructions.

   • If the guide does not list steps to reset the CMOS: Continue with these steps.

4. With the computer turned off, press the power button ten (10) times to fully discharge electricity from the system.

5. Ground yourself to discharge any static electricity. Place one hand on the case of the computer, and then place the other hand on a metal surface or grounded object, such as the metal part of a lamp.

6. Open the computer to access to the system board.

7. Remove or disconnect the CMOS battery from the system board.

   

8. Confirm that all sources of electricity are removed or disconnected from the computer, including the CMOS battery.

9. Press the power button for a minimum of 60 seconds to drain all power from the computer and reset the CMOS values on the system board.

10. Reconnect or reinstall the CMOS battery, and then close the computer.

11. Plug in the power cord to the desktop, and then turn on the computer.

    A message is displayed that confirms CMOS reset. The message varies by model.

    
    

12. Confirm that the Time in BIOS is set to 00:00.

    If not, repeat the steps to reset the CMOS, but press and hold the power button for 120 seconds when draining all the power from the computer.

[Ferrous]

after resting the CMOS I have the same error blink code six long red blinks/beeps that repeat five times.

[erico]

"The Diagnostic LED blinks red 6 times and the system beeps 6 times (once per second), then a 2-second pause follows: This indicates a pre-video graphic card error. To resolve the issue, complete the following steps: 1) Reseat the graphics card."

If that does not work, you may find yourself having to replace the video card.

[Ferrous]

the PC now wont turn on at all

[erico]

That is what happens when the video card check that is part of the pre-power on test fails.

[Ferrous]

so I am looking to replacing the video card then? 

[erico]

Yes.

[Ferrous]

thank you for your help.

[Brian1965]

Hi Ferrous,

6 beeps indicates a graphics/GPU issue. The below is from the HP Z420 Maintenance and Service Guide;

If your graphics card requires auxilliary power then ensure you have the power connector fully seated.