HP ProDesk 400 G5 Mini Blinking white and doesn´t turn on

[X-E-Qt-R]

Hello there,

I just saved an HP ProDesk 400 G5 Mini PC out of the trash and troubleshooting it to bring him back to life again.

I tried everything now, changed CPU, added RAM, changed BIOS Battery, and took everything out, nothing helps.

Just if I take out everything and plug in the PSU it beeps and Power LED is blinking red. If I put it every Hardware in and plug in the PSU its doing nothing, just blinks white. If I press and hold the Power button the HDD LED and Power LED blinks white. If I do nothing just the Power LED blinks white. It doesn´t turn on in what ever situation I tested it. I don´t get it, whats wrong with it? Is the board dead or can I do something to save it? I´m running out of ideas 😞

I searched now everywhere for a solution but didn´t find anything.

Thanks in advance

X-E-Qt-R

[BeemerBiker]

Here is a list of beep or blink codes page 84-85

https://hp.it-shop.bg/uploaded/6/3/ProDesk-400-G5-DM-MSG.pdf

borrow a speaker if you to not have one.

I looked over at eBay for images of the motherboard and the HP board does not appear to have any of those problem electrolytic capacitors which is a good sign.

Remove the CPU**, get a good magnifier and a flashlight and compare the socket to images of defective intel sockets.

**A CPU should be removed by using a suction device such as the type used to remove small recessed light bulbs.  Alternately hold upside down and release so it falls into fingers.  Never slide a CPU to center it even a tiny slide can bend pins.  Dropping can also cause the pins to shift and short out.  Modifying a case using a drill or Dremel should always be done with motherboard removed.

It is also possible the CPU you tried may be newer then the bios on the motherboard.  I once put a high performance CPU on a motherboard that had too old a bios.  I had to buy a cheap CPU with built in graphics so I could upgrade the bios to get faster CPU to work.