Furthermore, I have several of these systems and tried sourcing 3rd party power adapters online. For this aspect, not one of them worked correctly.
I did a write up here: https://old.reddit.com/r/homelab/comments/11o0x5o/dell_3050_...
Edit:
I ran the `cpufreq-info` command in your write-up and it gave me the correct:
> hardware limits: 800 MHz - 3.00 GHz
Maybe it's because the usb-c to barrel jack cable I picked up was marketed for dell laptops?
https://hclxing.wordpress.com/2014/02/09/hacking-a-dell-powe...
046 is the output current 4.6A instead of his partitioned as 46(there are power supplies output more than 10 amps).
The 22 bytes is the Dell PPID, which should be also present on the charger's label or the box: CN: Manufactured in China, some of them are TH which means made in Thailand. 09T215: Dell Part Number. 71615: Manufacturing factory code. 438: 2004 or 2014, March, 8th (Dell use YMD 3 bytes thus it is a lossy conversion always). 35EAL: This should be the serial number.
The last part 03 is a CRC16 (x16 + x15 + x2 + 1) checksum.
The great thing about these Optiplexes is that they use a standard 20v 4.5x3mm DC jack for power. I run mine off a UPS with a usb-c to barrel jack cable.