BEEPS ARE CODES, MOST TIMES, LIKE SAM,.MORSE CODE BUT NOT. SEE?
THE COIN CELL BATTERY IS DEAD, ON ALL THESE AND CAN NOT BE Ignored, below 2.9vdc is bad. (the cliff of deathh)
SO RAN BEFORE, NOT BOUGHT USED DEAD.
A 2004 PC mobo, AND NO COIN EVER LASTED THAT LONG EVER. 13 years old and is sold at wal-mart for a buck. CR2032
SORRY BUT IT CAN NOT BE IGnored ever.
so old it has AGP slot. and is to be avoided that as 1/2 the cards made for that slot fail hard. or go mad used, chaos mode. see?
so only use mobo VGA , and I think you did but not sure , not clear.
the goal is BIOS screens only, no HDD present no dvd drives.
just mobo and 2 power cables. seen here both\
https://www.manualslib.com/manual/732481/Aopen-S651m.html?page=4#manual
it uses the old 20pin PSU's back from the darkages of PSU PC
but most PSU have 20/24 pin conversion plug and Im sure that is here.
the min system is easy
PSU good, mobo, 1 stick of ram bank0., vga from mobo only to monitor. use the power button correctly and pushed for 10 seconds and released. NO PCI cards, no agp, and not drives !!!
focus on BIOS only. get BIOS working do the cmos clear jumper steps , in the manual.
also after coin cell battery the BIOS needs to be reset.
this relic has lots of mobo jumpers to get right, seen in the manual.
all must be set correctly that and bios settings and is not easy then.
newer MOBO were made smarter and less jumpers and far better bios . (best is mobo with no AGP slots at all, and one x16 PCI-slot.
AGP is a pain, nothing ever made then was worse. even voltage rules and BIOS card black lists. then, no kidding.
in BIOS set the VGA (igpu) local to here, not AGP defeat AGP
wow page 7 is super good, not seen today, back then they did this great page, trouble shooting, do not use any AGP card.
they did have PCI video card then and on some cases then
the PCI must be used first before AGP. yes dirty tricks
but forget that NO CARDS testing is first;.
https://www.manualslib.com/manual/732481/Aopen-S651m.html?page=7#manual
more,?? sure
IDE disabled in bios fully
Floppy disabled same place
Del key is BIOS hot key (numpad) and numlock
must be OFF.
worse yet, some relics only work on P/S2 jack to keyboard.
ouch (i still have mine ,just in case, deep in attic archive)