DL380p Gen8 | ILO Health Degraded & Display is turning black soon after OS starts to boot

Team,

I'm facing the problem mentioned in the below url's. To start with, one day i noticed my server has stopped responding to mstsc but reachable via ping and C$ share is accessible. When I checked in Data Centre, I found that Display is not coming on KVM screen. I hard booted the server many times but no luck. Every time I used to see the Initial Boot Screen for HP Server, then actual HP logo with options to choose from F9, F10, F11 etc and finally windows used to start loading with the activity wheel running under Microsoft Logo for a while and then disappear to black screen. I connected an external monitor to front VGA port and later tried with back port too but the same results.

Since ILO was not configured, I configured ILO hoping to work from my desk and also see the errors in IML log. I noticed that my firmware version was very old (1.xx) so I immediately downloaded the latest SPP for DL380 Gen8 and tried to update firmware. Everytime ILO kept disconnecting with session time-out error. I somehow managed to create a USB and luckily after many attempts it installed the updated firmware. ALso, 1 hard drive from Raid 1 (2 drive mirror) was failed and I replaced the drive.

I manually downloaded ILO firmware and updated separately to make sure I'm running the latest for the server. I then noticed in my ILO page about ILO health is degraded and further navigating lead to the articles below.

I followed the articles and formatted the embedded flash/sd card and unplugged the server from power source and later plugged it in back. I noticed that the error used to disappear and again appear after 30 seconds. I tried two more time but same result.

REF URL:

https://community.hpe.com/t5/ProLiant-Servers-ML-DL-SL/HPE-DL380p-GEN8-iLO4-Self-Test-Error/td-p/6979847#.XoHNOvFRXmw

https://community.hpe.com/t5/ProLiant-Servers-ML-DL-SL/SD-CARD-Embedded-media-initialization-failed/td-p/7017878#.XoHN8_FRXmx

https://support.hpe.com/hpesc/public/docDisplay?docId=emr_na-c04996097

https://support.hpe.com/hpesc/public/docDisplay?docId=emr_na-a00048622en_us

Having described the problem, my queries are:
1. Since it is ILO embedded flas/sd card, can we disable the ILO completely for now and proceed with OS boot.

2. What could be the issue with OS booting? Is it the display or vga or OS itself?

3. The articles are telling about motherboard replacement, is that correct?

Thanks in advance

Khan