first off , the coin cell battery RTC CMOS is now dead. no COIN lasted 12 years,? so... replace it.DO NOT INSERT ANY USED BATTERY HERE< buy one fresh, or it WILL FAIL. or learn how to use a voltmeter DMM on the battery sides (top bottom) below 2.9vdc is bad.Did you buy this USED PC dead? ????? if yes anything can be bad , or just jumper set wrong, so easy to do.there is a story here, I am sure. not told, a short history.The PSU is custom (NON-ATX) on in this HP work station as is how the Xeon CPU works. and has no iGPU inside.This PC does nothing if the GPU card is missing, in top slot. x16. blue socket coded.PC right cover open second slot up is blue and is GPU card only. as the manual shows you clearly page 43.put in a new $1 coin cell from walmart (lane #15 exit buy it get it put it ) battery rack, see CR2032,? BINGO.motherboard jumpers set wrong, PAGE 15 IN THE MANUAL, SET THEm correctly.CPU socket pins bent?The PC must beep., if CPU or PSU aRE DEAD.bad PSU" if PC is a no beep PC for sure not beeping with GPU card missing, that is a beep code.https://downloads.dell.com/manuals/all-products/esuprt_desktop/esuprt_dell_precision_workstation/precision-t3500_service%20manual_en-us.pdfread page 12/13 for the fabulous, HP , LED POST ERROR panel? that works even with no MONITOR AT ALL?the LED there form a 4 bit post error codes.and the extensive BEEP errors,, lots of CMOS beep errors here, possible and expansion card, errors too.SILENCE IS NOT A GOOD SIGN NOW.this PC is backwards workstation, the insides are BTX class backwards, right side access only backwards.the video card must be in the correct X16 slot, per the manual and look like no other PC made, due to BTX layout rules.https://pcdied.com/cmos.html
2009 year, 15 years old, and all that older are dead, never fully serviced ever)Dell Precision T3500 Workstation Technical Specifications ProcessorsIntel® Xeon® 3600 or 3500 series processorsOn some rare cases all the above is good and the PSU is bad, (logic inside for power on; power_OK)the ORANGE LED is STAND-BY power OK on the MB ( do this.reset now) 1,2,3,4, reset, https://pcdied.com/PSU/hard-resets.htmlhere is a list of steps (macro) to do.new coin cell battery never (USED) brand spanking new and at 3.3vdc, never below 2.9vdc allowed ever.then in BIOS page 1 and more, set data and time, set PXE to disables, set boot order to HDD0 top of list.then click SAVE key ( the screen tells you clearly this key chioce)then click EXIT, Do not skip SAVE or you will fail every single time.hard boot the PC cold boot and make sure bios held what you just set, if not the PC mobo is failing.then do https://pcdied.com/PSU/hard-resets.htmlthen make sure PC passes Diagnostics form DELL.com (power on hit F12 see diag choice?)now get a good HDD and load your OS< for sure 15 year old HDD are NO GOOD now this OLD.NO OS runs on bad hardware ever.NO OS runs on any BAD HDD, ever.rules are not flexible in the hardware world. or find a SHOP To fix it , YES !or with any kind of dead or weak coin cell ever, nor marginal ever.here is short list. based on BEEPER dead and the 4 LED errors dead too on front panel, dead too, no codes, POSTARE THE FANS ALL DEAD? THEY MUST NOT BE SO. EVER.unplug PC from the wall , new RTC CMOS coin cell battery, then,..1: fans dead, say so.? never skip telling what fans do or beeps, or the 4 magic LED codes, for POST errors.2: PSU dead. 3: missing GPU card or using the wrong one, not told yet, what card is in there nor in what slot. blue slot is best.4: jumper wrong.5: CPU socket pins bent. by other owners, (if PC bought used and bad)6: wrong ram used test them 1by1 in bank0 slot0 channel A , one by one, 4GB max per strick 24GB max PC total1333Mhz DDR3 unbuffered SDRAM memory, ECC RAM also in matched sets. same.DDR3 DIMMs have 240 pins, the same number as DDR2 do not USE DDR2 RAM of FAIL hard it will. do not force the sticks contrary to the key in the card (keyed they are)learn 4 things, beeps, not told, 4bit binary POST errors LED on front panel not told use GPU card X16. and what fans do, answer all must pins for sure CPU and PSU, and if GPU has a fan it too must spin (this era)that is it for now, lacking all visual facts not told. Can not see your screens.can not hear your fansnor here the beepsnor see the 4 bit binary codes on front panel display.No USED CMOS batteries used, ever, spend a buck and buy a new one ,fresh and perfect. or the ROAD to success will fail.Manual coverage for power LED acts !power button single LED ( 5 acts possible and not told yet)No light—System is in the off state (S5, or mechanical (AC power not applied) OFF).Solid Amber—System fault, but Power Supply is good—normal operating state (S0 ).Blinking Amber—System fault error condition including Power Supply (only +5VSB working), Vreg failure, missing orbad CPU.Blinking Green—System is in power saving states S1, S3 or S4. (Blink rate is 1Hz). No fault/error condition.Solid Green—System is fully functional and is in S0 (ON) statethen total:there are 4 green post lamps LED in the front panel (4 bit POST error codes)there one lED in the mobo, center for standby powerthere is 1 power led amber or green.be clear whan talking LED< I can not guess which ones, and all 6 must be seen, to know WHAT'S UP.and beeper, the 7 thing to see and reportand last fans dead or not. hear , seen or felt.