Cannot boot flash/OS/etc from USB

[BMC_MT]

Hello all.  New user here.  I've been online for the last week trying to figure this out, browsing this forum as well as any others that google or yahoo would bring up to help me fix it.  I have an HP Pavilion 15t-n200 laptop given to me by my sister roughly 6 months ago.  She was getting ready to toss it because she kept getting the BSOD.  With some digging and diagnostics i found out that the HDD was faulting out and used DBAN to see if it would fix the problem.  Sure enough, it did the trick.  I'd been using it daily since that time with zero issues at all.  No slow booting, random freezing, anything of the kind.  I recently tried booting a Linux OS, just something to play around with and it was working just fine.  Then about a week ago my laptop wouldn't recognize my USB image to boot.  I've tried everything i've read about this, removed the RAM and moved them to different slots, reset the CMOS battery, did the stored power drain holding the power button without the battery/adapter plugged in.  Nothing works.  The only thing i had left to try was disconnect the HDD and FINALLY i could get back into the BIOS menu.  But now even with the boot manager I can't get my USB drive to detect.  I've reformatted several times, used different programs to do so, with no luck.  I also tried the HP Bios Recovery flash method with no luck, considering the USB is NOT showing up in the boot manager.  Also, this was after making sure that Legacy boot was enabled and the boot priority has the USB at #1 on both UEFI and Legacy modes.  I've tried resetting BIOS to defaults as well with no luck.  I"m completely stumped.  Does anyone have anything else i could try to get this working??

EDIT:  Forgot to mention, at this point, when i turn the laptop on with the USB drive plugged in it will just hang at the intial screen "Press Esc to pause startup".  I've tried this on 4 different USB drives, each work just fine so i know it isn't an issue with the drives themeselves.

[CherylG]

With the extensive troubleshooting you have done I am pretty sure you probably have tried a different usb port? Port on opposite side too? Not unusual/unheard of for  usb ports to fail on a laptop.

Does it still boot from hdd? A faulty hdd can cause the problem you had entering BIOS.

[BMC_MT]

Thanks for the reply CherylG.  No ma'am it does not.  When i originally got the laptop, my sister was mentioning she had checked a few places online and that the hdd was most likely the issue she had.  When i got it, i ran DBAN on it along with other diagnostics and they also pointed to the hdd.  After running DBAN fully through it (took about a day and a half), it worked just fine.  The few things i tried was disconnecting the HDD completely to see if i could access the BIOS and i could with every try.  I thought that may have fixed my issue, but from there i couldn't boot anything from USB.  And yeah unfortunately after trying out all the ports, none of them would boot.  But peripherals like mouse/keyboard work just fine in every slot (it has 3 btw).  Last night the very last thing i did was connect the HDD considering i couldn't do anything else at that point and i was SOMETIMES able to access BIOS, but i would say maybe 1 out of every 10 or so attempts.  And every time it would just hang when trying to boot from the USB.  A few times i was able to get my USB to show in boot manager through the BIOS, but when selecting the drive the screen would go black, like it was trying to boot but just hang there.  And it wasn't the usual "black screen" when you see the typical problems, i.e no backlight.  This looks just like the boot up screen without the text.  I'm at a complete loss.  I have an older HP G61 laptop kicking around that has a 250GB HDD, so i gave that a try too, figured it couldn't hurt anything.  And still nothing.  I'm going to tinker around a little more and do some more research online to see what i may be able to try.  Honestly i don't know of anything else to try.  I contacted 2 of our IT guys from my job via email last night detailing this and they are leaning towards an issue with the BIOS as well.  But they offered to take a look at it for me, so hopefully i can drop it off in the morning if i can't get it figured out today.  Also worth noting, not sure if i mentioned this yet, but i did also try removing the ram sticks (2 of them) and using both in different slots and individually with zero success.

EDIT: I also forgot to mention this; around a week before this happened, i DID try to split the internal hdd into another partition just for dual boot purposes, that way i wouldn't need to depend on the USB method, instead i could just select which method to boot from on the internal drive at start up.  Considering that the BIOS can be accessed when the HDD is disconnected, i could see that causing an issue?  Maybe a bad partition that i didnt catch?  But then again, i wouldn't think that would explain as to why the system wouldn't boot from USB without the hdd attached.  In the small case that it would though lol, i thought i would bring that up.