Presario F756NR strange boot problem

Hey everyone. My Compaq has the strangest problem....

When I turn on the power button, it gets stuck at the Compaq boot screen for about 15-30 seconds (I haven't timed it), and then restarts. It does this EXACTLY three times before it will boot from anything. Currently, I am running my OS off of a USB stick because I have no optical drive or HDD. I know it is not the OS or USB stick because I have tried multiple OS's and USB's and they all have the same problem.

It isn't a huge issue, but it does make startup annoyingly slow.

I have ran a memtest in the bios and didn't get any errors so I am assuming it is not the RAM. About a year ago, I found out that after my optical drive died, it would make startup slow. After I disconnected it, the computer would boot quickly, but I am experiencing slow boot-up again and this time it's stranger than ever.

I tried turning the laptop once without the power cord, and once without the battery, but the power cord plugged in. Both times the strange issue persisted, so neither of these seem to be the problem either.

I also tried a hard reset, but it didn't do anything.

Now, on another forum, one user suggested that the motherboard may be the culprit. Would any of you know how to test this?

Could it be the motherboard, something else? I'd love to hear your suggestions.

Thanks for your time.