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Honor Student
Posts: 3
Member Since: ‎11-14-2009
Message 1 of 5 (2,656 Views)

Problem booting HP Pro All-in-One 3520 Business PC

Hi all,


I have the following problem with my HP Pro All-in-One 3520 Business PC:

when I turn it on, one of two things happens:

- either it boots up without any problem and I can use it, restart it, and shut it down without any problem;

- or it boots up (I hear the fan and harddrive) but the screen stays blank. Funny detail: when this occurs, the usb-connected keyboard does not work - like it is getting no power. None of the lights (scroll lock, Caps lock) work. The mouse (laser mouse) however does get power.


When I unpower the unit for a while sometimes it work rightaway, sometimes I have to press and hold the power button several times before the screen (and keyboard) works. There are also times when it just does not work at all and I have to wait to see if it works the next day.


I have removed and changed the CMOS-battery and checked all the cables. The thing that intrigues me the most is that it seems almost random whether it works or not. And when it works, there are NO problems whatsoever.


Any idea what might be the problem? Anyone have the same problem? The unit was bought 1,5 years ago so is out of warrantee.

0 Kudos
Posts: 44
Member Since: ‎05-13-2015
Message 2 of 5 (2,269 Views)

Re: Problem booting HP Pro All-in-One 3520 Business PC

There is a possibility that the power supply or motherboard could starting to have some sort of issue. If you have your Desktop plugged in a surge protector or back up power supply, that could be the issue, try using a different power outlet without a surge protector. You could take your desktop to a local HP Authorized support provider to get a better idea of the exact resolution to your problem


Here is the HP website to find a local ASP:

I work for HP
Posts: 1
Member Since: ‎12-24-2015
Message 3 of 5 (1,823 Views)

Re: Problem booting HP Pro All-in-One 3520 Business PC



Recently I got exactly the same problem.

I was told in the service that it might be the grafic card but as it is installed into motherboard, then I have to change the whole motherboard which costs almost same as pc. unfortunately there is no option to install dedicated video card at least to check if that is the issue without reaplacing motherboard.

Trick with power cables didn't work for us as well as manipulations with various cables (we have 2 of same hp  pro 3520 so had possibilities to try different combinations), computer continues to live its own life, most of the time blank.

The question I wonder is reasons why motherboard or videocard could have failed? PC was treated well and worked as usual, and one day it just happened. The question is also if it is worth investing so much money in motherboard which can fail so.



Honor Student
Posts: 2
Member Since: ‎04-06-2017
Message 4 of 5 (526 Views)

Re: Problem booting HP Pro All-in-One 3520 Business PC

Hej. Recently I inherited my late neighbours HP - it's showing exactly the same fault! It can boot flawlessly - but that's not one time out of ten! 'Everything' has been tried, contacts cleaned, RAM out etc, but nothing seems to help. Did anyone find a solution?

Honor Student
Posts: 2
Member Since: ‎04-06-2017
Message 5 of 5 (456 Views)

Re: Problem booting HP Pro All-in-One 3520 Business PC

Hej. Since you have two identical machines - have you tried to swap RAM? I suspect first 64 kilobytes of RAM to be defect. Mine is showing exactly the same, only are two weak beeps to be heard, POST is never fulfilled. The beeps could in no way be confused with the very powerful beeps when RAM is completely missing

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