5820 beeping

1, 4 One amber blink followed by a short pause, four white blinks, a long pause, then repeats. Bad Coin Cell Battery 

CPU configuration activity is in progress, or a CPU Failure was detected

Contact Tech Support

A Reference Guide to the Precision Workstation Diagnostic Indicators

Replace the size 2032 motherboard battery and see how it does.  Used and refurb places usually don't replace the battery.

@bradthetechnut​ it didn’t blink white. It had a beep and an amber flash. Then 4 more beeps with 4 amber flashes

Boot the system up and immediately tapping on F12 for one time boot menu.  There, you can select to run diagnostic scan.  As beep codes or LED light codes may not cover all errors or issues.

As this is a newly received system, perform some cleaning, change CPU thermal paste, and give system a new coin cell battery.

@Chino de Oro​  I’ll try replacing the battery and see what it does

The 5820 dates back to 2018.  "2017 to current" is the drop-down I used in the link.  I couldn't find a 1,4 beep pattern in Dell's diagnostics.  Just a 1,4 amber blinking pattern.

Sometimes some people wish for it to be something bigger than the battery.  But when it isn't, they just sidestep solving the problem.

A bad battery affects BIOS and therefore PC operation.

I see Chino beat me to my last post.

@bradthetechnut​  I just tried two different batteries, and the same results. Granted both those batteries were used so tomorrow I’ll buy a new battery and test it. And The beep sequence was 1, 3, 1 then it will play the musical tone again and keep repeating the same sequence.

It seems that your system has some memory issue.  Run diagnostic from BIOS boot menu for full system checkup.

@Chino de Oro​  I can’t do it tonight. I don’t even have a gpu installed in it yet.  I’ll run the test when I get a chance and report back. 

@Chino de Oro​ if my bios is corrupt, I won’t be able to boot into bios, correct?

Correct, a corrupted BIOS "bricked" the system.  Can't even pass POST.

Just wait 'til you get all necessary requirements for system diagnostics and performing maintenance works at the same time.

Review system manual to get familiar with your new system  https://www.dell.com/support/manuals/en-us/precision-5820-workstation/precision_5820_om_pub/internal-view?guid=guid-714924cc-95cd-48ce-ba7c-4928a50c0e15&lang=en-us

@Chino de Oro​ I have a dell 7810 also with ecc memory. Will those modules work on this system also? That way I can see if it is faulty memory?

Yes, the T7810 uses RDIMM ECC memory.  Although at slower speed, it can be used for testing if your T5820 is with Xeon CPU.  It won't work if your T5820 has Core-X.