Optiplex 9020 MT blinking amber power button 23 no post

According to Dell documentation:

2, 3
2 blinks followed by a short pause, 3 blinks, long pause, then repeats
Bad Motherboard, Memory or Processor
If you can assist to troubleshoot, narrow down the issue by reseating the memory and swapping a known good memory if available.
If nothing works, replace the motherboard, memory or processor

That leaves something to be desired, but what I could find.

3-2 is a Video problem.  I suspect yours is the 2-3 code.

I'm leaning towards bad cpu.  I think I will remove the fan and see it the cpu is heating up first.   Pretty sure the memory is good. 

CPU gets very hot after about 30 seconds.   Have another on order for a Lenovo board that I will try.  Memory swap next. 

Tried multiple memory sticks.  No difference.  If you remove all memory,  the board beeps a pattern.  Seems like it's alive. 

Clear the CMOS memory and see if that changes anything.

With it powered off, remove the CR2032 battery located on the motherboard for at least 10 minutes.

do not remove any CPU heatsink ever, and run any PC, ok. DO NOT DO THAT, torture test.

I know you said fan but that  too is not needed ever, all CPU burn power (waste, so let it work let the fan run)

would you do that to $500 CPU, no. yes it self shuts down but way do that and TEMPT FATE ?

first off did you do the long hard reset. and check RTC Battery voltage first, 1st things 1st?

LATCH UP HAPPENS, in power rails and INPUTS to all CMOS chips.on the later by design.

below 2.9vdc is a dead coin cell. We never skip this step. (on any funny acting PC of ANY KIND with COIN)

That is always first and BAD CPU is always last, ever seen one really bad,? no, unless hit by lightening.

 moving CPU to other PCs not certified to run the CPU is just a total wasted effort, (or last in the long list of tests if ever... ) (Intels chips are super super robust)

Do you want  to test or GUE$$?

if you must guess why not a new  PSU, they do fail.(easy too they run HOT and HOT= lower life, in ELECTRONICS for sure caps baked dry, etc...)

if the PC coin cell is ok, and the hard reset fails.](posted 100 times here, 1million times world wide)

next is  not guessing it is testing and the strip down testing next,  as seen here.  clearly,. A MINIMUM SYSTEM TEST ! is NEXT.

your fans run, but does the DVD tray eject? button there near tray, if DVD or BD present.

or bench testing the PSU,  easy ,ask, (level 1 tests work,  full load tests you can't do)

Beyond this is only  trying new part on minimum system

saw one guy with PC like this  and  had shorted USB cable, and the PSU (VBUS Driver chips) make the PC lockup and even reboots. or stalls.  (no 2 PC made act the same way with USB shorts to pin1.) that is a fact

so that is why USB devices are all removed first. (have proofs of that is you want to read it)

but good luck,  (seen one guy replace mobo 3 times and still  failed) oops the HDD power feed was shorted.

learn that all devices in all PCs can short, some do that until reset other are DEAD shorted for ever.

The PSU in your PC should shut off. for any overload, but the 9020 is the odd duck DELL PC with no 24pin power plug  and how it does overloads , ive no clue. but all mine are not converted to ATX and known. by me.

This PSU have is 12vdc only PCU, totally unlike the rest of the world uses on desktops atx.

I bet the hard reset fixes your PC,  as does millions of others..... endless story on latchup or ESD caused.

if hit by lightening I do wish you luck as that has no limits at all on damage.

I tried the CPU (I5-4690) in the Lenovo M73 tiny and it will not boot.  This CPU, however, is not on the approved CPU list for that model.  The I7-4765T is the fastest of only 3 on the list.   I know that 9020 MTs commonly shipped with I5-4570s but have not been able to find a compatibility list for the 9020 MT MB.  The 4690 is only slightly faster with the same specs so I thought it would work.   Maybe not. I changed the CMOS battery to a fresh one but it didn't change anything.  

23 ,means unknown main board error (key word unknown)  after all if the screens dead ask self how smart can it be, and ePSA diagnostics dead TOO)  change words mainboard error to main board not happy. (works better)

32 is usb shorts. (simple no?) remove em.

The facts are the BIOS screens are dead ,(coin cell dead) some PCs go dead when coin dies, to fool hackers.

The BIOS dead means the video port is dead, or the CPU can not processes the FIRMWARE instruction  codes.

If you have PCI video card, (no system CONFIG, told by you, what's inside PC in slots)

then try the IGPU video  port. next,  or is is this plugged in wrong now?  my PC has 6 video ports, do you?

But all this smacks to me of VRMs have shut down on the MOBO or even one of the 2 power cables from  PSU has dead 12vdc RAIL. there are 2 cables both must show 12vdc.

the VRMs on the mobo will shut down for any overload, what the PSU does , IDK, and id never cause short on mine just to learn what dell does here. (unlike real ATX , the MOBO tells the PSU to shut down for any kind of overload. (VRM = voltage regulator  modules) Dell uses more that any other with ODD PSU lacking same.

so if this is true , then any thing plugged in to any motherboard can cause and overload, PCI, USB, SATA power. and all that. that is why we do the strip down tests. 3th,    (coin first, hardreset 2nd, strip down 3rd)

1,2,3

In electronics , power is first, clean and accurate and noise free clean power, or all else fails.  a key skill to learn.

Are all the RAM sticks the same capacity, speed, and brand?  Some Dell's, notably the ones that are little bit older, and some other PC's, can be finicky about that.

In case it is the RAM, I'd reseat the sticks, powering on in beween to see if the same error repeats.  Of course, make sure PC is unplugged anytime working on the MB.

If it helps:  Optiplex 9020 MT Owner's Manual 

Optiplex 9020 Spec Sheet 

I could never find a tech guide for the 9020, yet there's one for the 9010.

Dell Diagnostic Indicators 

9020 MT uses proprietary power supply.

7VK45 365w, Huntkey
T1M43 365w, Delta

365w PSU =
Huntkey  CN-07VK45       HU365EM-00
Delta      CN-T1M43         DPS 365CB

There is a Moddiy Adapter for this OR there is an OPTIONAL 365w power supply.

EVGA 700BR with Moddiy Adapter is recommended.

https://www.moddiy.com/products/Dell-OptiPlex-9020-PSU-Main-Power-24%252dPin-to-8%252dPin-Adapter-Cable-%2830cm%29.html

the ram is tested at the strip down process

its just one thing of many that can fail, for sure any module can do that, for  sure any and all shared major resources, power , data, address and controls ,etc.

the only way to diagnose  any PC is the full power reset, then stripped down.

Image you had a home and when one room door is opened, all the air in the whole home goes to a 0"HG vacuum

zero bar, air is now gone,  same as the MOON.(scary no, sorry)

what would you DO?,  well for one close that door. fast. (or remove the room (it has blackhole inside)(as seen on TV horror channel1)

same on the PC remove all modules first per instructions. already stated by me and for sure others 1000s of times here... really!

a.k.a: a minimum system.  (even the case is optional )

all cables from MOBO not PSU  pair . pulled, even the front panel i/o on a dell could in fact short. (do that too)

This PC has 1 power button cable and must be connected and working. for power on to work and does here.

all cables to sata gone. power and DATA cables both.

all USB devices. all. (front rear and on some dells 1 inside, rare latter)

all ram but one test them 1 by 1,  the manual shows you where bank 0 channel A is, use that slot,

even no ram at all beeps, telling you BIOS is not 100% dead. just mostly dead?lacking some RAM.

the goal is get F2 screens up get the dell splash screen up get the splash bar  (post progress) bar reach the end. (I cant  watch your screen so answer get long lacking such facts)

if the screen  bar sticks (stalls) mid way, POST IS FAILING.!  why only remains.

have PSU, MOBO and CPU connected. just that, and last 1 stick of ram try all sticks of ram  1by 1.

if ram was ok before you can bet 1 still works, right?  unless hot swapping them (dead wrong that)

pull the AC cord and the push power for 10 seconds, I do it 3times for 3 seconds, some dells I have twitch fans 3  times this way then go dead, telling me DC bus is now dead,  (do so) even wait 1 hour AC pulled is prudent.

"the first rule of services is, DO NO HARM"  same as the Doctors used to do ".

learn that MOBO and Friends, can in fact latch up at any surge, (large)

and must be reset correctly to end those CMOS devices that did,  all PCs have CMOS so.... there you know.

CMOS VDD destructive latchup (smoke too)

CMOS VDD nodestructive....

and CMOS inputs latching up (no harm if lucky) and resets easy,  (this is for self protection too)

the cure is easy , get all rails in the PC to 0.0vdc and 99% of the time the MOBO wakes back up.  seen this 1000s of times now,  do not replace any MOBO until you learn this, ok? or go broke fast.

if confused ask trained tech to do this, some are.

I use a ESD grounding wrist trap to work inside PC for sure expensive ones.....  if not you make it worse.

Do not ESD zap anything inside, for sure if ICE is outside home and humidity is zero percent in the shop !!!

Both computers turned out to have bad motherboards!  Lightning strikes twice!  Lesson learned?  - Avoid used barebones units with CPU removed.   Why remove parts from a newer working computer and sell them instead of selling a working unit?   One has a warranty, so I can return it, and the other company is no longer listed.   Thanks to all posters.   I used a PCI MB tester that showed multiple board fault codes. 

so true

buy mobo with cpu , present, even some near useless $1 celeron.

many used boards are bad, its what ebay sells. many   that say sold as is, are for sure bad.

get the NO DOA promise and get refunded more easy.

the answer some are no CPU on board is because the cpu can be very valuable to sell top gamers,

the remove it, and sell on 2nd listing.

keep some old Celeron in your KIT, use it to test the Mobo. 

but sure ebay is a crap shoot.   (make sure the say no DOA) ok>?  and have no negatives, ( but 3 out of 100000) ok. make sure  they have store , if not  it can be a kid selling out of moms basement. clueless what he just sold... really.