Server Constantly Rebooting

[Nunciate]

I have an Apollo 4510 G9 Chassis with a ProLiant XL450 Gen9 Server installed in it.
I have used this server for several years and it suddenly started rebooting all the time.

I have Windows Server 2019 installed on it.  All the most recent firmware, bios, and drivers are installed.

I use this as a backup repository for Veeam.  I have 2 fiber cards, and 2 board NICs.
The fiber cards connect back to the production SAN via FC Switches as well as a Quantum Tape library.
If I start backup to disk jobs that pull from VMware over Fiber from the SAN the server just reboots within minutes.  No event logs other than the normal startup logs.  No Blue Screen.  No dump files.  No alerts or events in the ILO other than a message about an unexpected reboot.

At one point the PCA Riser board (where the PCI cards are installed) was misaligned and one of the pins bent.  I had that replaced and don't seem to have any issues with that.  Still, I asked to have it replaced again just to be sure, and after that things seemed to be OK again for about a week and then the reboot started again.

Another oddity I noticed both times that part was replaced was the server would post to about 2 percent and power off.  I'd have to power it back on about 5-20 times before it would post and boot.  Even though it would state that the fans were not working though I ever touched the fans.  Powering off, pulling out all power supplies, and reseating those seemed to fix it.  It booted to about 45%, powered off, and then when powered back on it was fine.   The entire thing is acting very odd to me.

I will also mention that I am using a Smart Array P840 Controller with 54 6Tb drives attached.  I also have 6 800Gb SSD drives installed and use those for the smart cache.  I have tried with and without cache turned on with no luck.   I have not seen any alerts from the controller about issues with drives.  Only alerts that there was data left in the cache after unexpected reboots.

I am out of things to troubleshoot. 
I did find this article and I applied this setting in the bios just now so we will see how that goes.  My CPU are Intel(R) Xeon(R) CPU E5-2630 v3 @ 2.40GHz.  This article says the issue is on v4 but who knows.

I guess if I have continued reboots I'll ask for the system board to be replaced on the blade server.

[Nunciate]

This was the advisory I applied and it appears it did not fix the issue.  The server just rebooted again.

https://support.hpe.com/hpesc/public/docDisplay?docId=emr_na-a00060570en_us

[support_s]

System recommended content:

1. Microsoft Windows Server 2003 - HP DL385 G2 Server is Constantly Rebooting

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[Anu_K]

Hello Nunciate,

Do you see any errors in IML entries or during the POST while servers is rebooting?

If not, you could try bringing the server to minimum configuration (For instructions, refer to page 17 of this doc. https://support.hpe.com/hpesc/public/docDisplay?docId=c04444029) to isolate the component causing this issue.

Hope this helps!