OS7100 resets for no reason occasionally. I suspect the MP10a processor. The LAN port has gone out on it also. No link lights on KSU or programming laptop. Would replacing the MP10 require me to get another license for voice mail? System is on battery backup which works fine. Or could this be a power supply/KSU cabinet related issue?

You can replace the MP10a and have vm still working. It is a built in feature and doesn't require a license. Hopefully you have a backup of the config for both the VM and Database. The other thing would be that the fan is going bad and will cause the system to reboot. Have you tried swapping out the KSU for the system? Could be a weakening power supply.

if it's a bad fan. this fan made by mechtronix from coolerguys works perfectly with the officeserv. the officeserv is very picky with fans if the LRA or Locked rotor alarm signal is not right coming from the fan to the MP10a the processor card will throw an intermittent fan failure code in the logs. that's what happened with me i got a compatible fan from a telecom reseller that said thier fan works in the officeserv as a replacement slapped it in there and getting fan failure messages in the logs every 30 seconds and the run light would turn red every 30 seconds.

found a tech on this forum who used this fan from coolerguys.com and said worked perfectly. So i tried it and for past 4 months no more errors or problems. i just cut the connector off the old one spliced it into the new one with solder and heat shrink tubing and works. the power draw seems to be little higher if i remember correct but doesn't seem to have any negative effects.

https://www.coolerguys.com/products...d-rotor-alarm-signal-model-g6015m12b2-rh

if your run light is green and flashing (normal operation)
run light flashing green then flash red then back to green (intermittent fan failure)
run light flashing red (fan failure) this is where it will start the rebooting process
run light off card issues or still bootup process

this is from my experience when my fan issues arose.

hope this helps any