Three long beeps followed by two short beeps

[Dave_Lonsdale]

Hello support community

This PC is only about 6 weeks old.  It came with 8GB RAM but I added another 8GB.  All fine showing 16GB for about 4 weeks but then noticed the % memory used was higher and discovered that settings/about and Speccy were now showing 8GB.  Tested both slots with the good memory so motherboard OK but then made the mistake of powering up the PC with only the bad memory as final confirmation.  Result was three long beeps and two short beeps.  Having put the good memory back, I still get the same beeps.  The PC does not start and no display.

I unplugged the PC overnight but did not resolve.

Please advise what keys to hold down on power up or whatever I need to do to restore.  If successful, will I need to refresh the BIOS and if so how to I get to the BIOS on startup with this model?

Thanks for your support

Dave Lonsdale

[old_geekster]

@Dave_Lonsdale , welcome to the Community.

I suggest that you reset the CMOS with the original memory modules installed to see if that solves your problem.  Here is the Maintenance and Service Guide.  On Page 87 is a guide to help you reset the CMOS.

[Dave_Lonsdale]

Thank you for your helpful reply Old_geekster.  Reading I can see that the CMOS needs resetting.

Unfortunately, my HP 290 G4 MT motherboard is not quite the same and the position where the blue link is shown in the manual, connector position E2 marked CMOS does not have pins 1 and 2 in the solder pads on the pcb.  Instead, immediately adjacent is a block of six pins, marked E49, on which two blue links are fitted.  Looks like pins 1&3 and 2&4 are bridged.

I removed both blue links, plugged in power and pressed the power on button.  Unfortunately, the result was the same - the power on button flashing (blue) repeatedly together with three log beeps followed by two short beeps.

I was unable to find a manual on the Internet that shows my arrangement, the area for E2 and E49 is marked CLR-CMOS/PSWD.

What do you suggest?

[Dave_Lonsdale]

Hello again Old_geekster (or another also having expert knowledge)

If a manual for my HP 290 G4 or the normal way of returning the CMOS memory to the factory default is not known within the community, when reading the HP 280 G5 manual, it appears that removing the RTC battery “clears the CMOS settings”.  Does that mean that when the battery is replaced, the memory will be reset to the factory default as per the (non existent) blue link and everything will be hunky dory?  Or will something bad happen?

[old_geekster]

You are welcome, @Dave_Lonsdale!  Thank you for the additional information.

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@Dave_Lonsdale wrote:

Hello again Old_geekster (or another also having expert knowledge)

If a manual for my HP 290 G4 or the normal way of returning the CMOS memory to the factory default is not known within the community, when reading the HP 280 G5 manual, it appears that removing the RTC battery “clears the CMOS settings”.  Does that mean that when the battery is replaced, the memory will be reset to the factory default as per the (non existent) blue link and everything will be hunky dory?  Or will something bad happen?

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Yes, removing the battery for approximately 20 seconds should reset the CMOS.  I didn't mention this since the motherboard appeared to have a jumper to do it.  It won't hurt the motherboard and we can only hope that this will solve your problem.

The CMOS is a chip that stores the BIOS/UEFI settings.  Once you make changes to the system they are not always cleared if changed back and this is what causes the problem.

[Dave_Lonsdale]

I was really sure this would fix it Old_geekster.  But unfortunately it didn’t.  I left the battery out for 10 minutes, then 1 hour and finally 8 hours.  Result the same - 3 long beeps followed by three short beeps and does not boot.  I suspect even you may now be out of ideas (hope I’m wrong).  But the PC is almost new so I guess tomorrow morning I will have to refer it to HP’s formal support facility and see where that takes me.  If I can get through over the phone or online chat and they fix the problem I’ll report back to the community.  (PS I’m in the UK but didn’t see the region setting until it was too late).

Many thanks again for trying so hard to help.

[old_geekster]

You are very welcome, @Dave_Lonsdale!

I am sorry that we didn't solve your problem.  Sometimes it is difficult from afar.  Here is a guide that may give you some ideas.  You will look at the section 3.3.  The explanation doesn't mention anything about the memory.

[Forsakenlance]

Idk if this helps but I have had beeps happen when I left a card out of its slot in my pc make sure everything is plugged in vibrations and bumps can loosen something

[Dave_Lonsdale]

Hi Old_geekster and Forsakenlance

I’m pleased to report that the PC is working again.  A HP engineer had to replace the motherboard.  I have also this evening discovered why the 16GB memory became 8GB.  I hadn’t realised it coincided with me fitting a I350-T4 network card in the PCIe-16 slot.  Apparently this card, along with some others, blocks the SMbus (whatever that is) and disables one of the two DIMM slots.  The SMbus signals aren’t needed on the network card so I cut the track to the relevant pins and now everything seems to be OK including having 16GB memory back.

[old_geekster · Accepted solution]

Thank you for the update, @Dave_Lonsdale!  It is great to hear that you solved your problem.  Here is an explanation of the SMbus that I found online:

"The System Management Bus (abbreviated to SMBus or SMB) is a single-ended simple two-wire bus for the purpose of lightweight communication. Most commonly it is found in computer motherboards for communication with the power source for ON/OFF instructions."