Compaq 6305 SFF not booting

[howdyhamster]

I'm trying to boot up this older computer we had in storage so I can reset it. When I go to start it up, it beeps once and goes straight to a black screen that has only the text "No option to boot to." First thing I thought was "ok, the hard drive is either bad or not connected." Tried a different drive, SATA cable, and SATA port on the motherboard with the same results. Even tried a bootable USB drive to see if it could boot from that. Next step was trying to get to the BIOS settings. Tried pushing the keys ESC, F2, F9, F10 on different startups, same results. Doesn't get to any sort of boot or BIOS screen, just straight to the black screen with the error message. Even tried holding the power button to drain power after unplugging it, reseated the clock battery, and cleared CMOS. I've tried everything I could find from searching the error message, and not sure where to go next.

Edit 1: should probably also mention there is no POST code on the front light, it's just solid green.

[savvy2]

HOW OLD IS IT? 2012 is not old.!

IF OLD THE COIN CELL IS BAD.. past 5 years , always suspect this first.... 7yr is max spec life. less PC parked. less in hot attic parked.  2.9v min, less is bad.

tried another HDD, with what on it????? empty drive is useless, its empty. as all new drives are.

better is any live cD/dvd or best is linux Koppix. v7 boot stick , make one and test the hdd.

Tried pushing the keys ESC, F2, F9, F10 on different startups, same results.

that means you lost power.... inside somewhere

does the fans all blow, PSU fan, CPU fan and GPU fan if fitted does it, clean the case yet>?????

never seen any 5 years old pc not full of tons of lint, why even turn it on , look inside first. for pack up.

what monitors, does the monitors OSD screens work?

using  PCI video card or the on MOBO jack, VGA?

it not the screen the screen works has  text so really this is not black screen post its a dead OS

 post. 

window login screen is missing.

but the dead BIOS is more serious.... . for sure.

this Business PC also has optional RAID, got RAID?

this pc has UEFI, so if the safeboot is on in BIOS, then you can not boot to stick or CD or DVD. until turned off

making tests imposible.

so bios is first , as it always has been 1981 to now.

your F10 page is here , 

the PC should prompt you with this. messessage,  hit xxx to enter Setup (HP bios./uefi)

it must work, this or try another keyboard.

try another USB port is wiser. with kbd.

the PSU might be bad.

there can be shorted modules on the PC  mobo

pull all SATA cables, all hdd, and dvd cables.

pull all PCI card,

does BIOS work now?  lean it down, pull things, try 1 mem stick. in back 0

do not flash BIOS, or get a brick .

[savvy2]

you have text,  so its not dead.

unplug it from wall, power one 3 seconds, as you told

wait 1 hour for caps to discharge more.

chips can latch up, so we do this.

the text tells you 2 things. some power is ok

screen works as does GPU chip not dead.

BIOS is the problem. I can be still a power problem , or PC overheats in seconds. CPU fan must blow and fins on Heatsink not packed in lent, make sure heatsing on cpu is not falling off. or lose, or CPU chip lock not sprung to unlock (omg)

BIOS dead is the true failure here....  most times is loss of power.  or PCI card shorted. or ram stick

http://h10032.www1.hp.com/ctg/Manual/c03481740