I delayed posting my rather anti-climactic solutionbecause I felt rather like an idiot + I didn't want to say something I wouldregret?¦and then life happened.  The notethat I wrote to myself then:  

I expect to be happy about this tomorrow.  Right now I just feel bruised from the mostlyunnecessarily long journey it took to get here.Seriously.

Suggestions to ASRock:
 

Whyperpetuate the incorrect descriptor 'error' codes -- why not call them Dr.Debug 'post progress' or 'post sequence' codes?
 

Wouldn'tit be helpful to share a FULL list of Dr. Debug codes and relatedtroubleshooting steps?

Why not share which Dr. Debug code indicates that all is well and no obstaclesto booting remain?
Perhaps a 'GO' success code?
No LEDs lit? 
 

If havingone stick of (maximum) 2133MHz DDR4 memory on the QVL is essential for theinitial boot (before installing more or faster RAM) -- shouldn't this be in themotherboard documentation?

Likewise, isn't the DIMM population priority sequence basic information thatshould be in the mb manual? 

@parsecdiscussed mem configs here Posted: 11 Jan 2016 at2:47am

<http://forum.asrock.com/forum_posts.asp?TID=1704&title=x99-extreme-6-code-b0-or-60>

As @parsecpoints out, "Unfortunately, when usingtwo DIMMs as you are, their location is ambiguous given thisinformation.  A non-intuitive bit ofinformation from Intel about the order of use of the DIMM slots isthis: 

Populate the the DIMM slots that are the farthest from the processor first.
Based on Intel guidance @parsec reasonably concludes that "Two DIMMs in a quad channel X99 boardshould be put in slots A1 and C1."

and "Very important, every time we move memory from one slot to another, we MUSTclear the UEFI/BIOS! If you don't dothis, you're on your own."

From<http://forum.asrock.com/forum_posts.asp?TID=1704&title=x99-extreme-6-code-b0-or-60>

Yet this(guidance to prioritize DIMM_A1 and DIMM_C1) conflicts with 'mem configs forX99 boards' image shared by 

@wardogthat indicates populating DIMM_D1 + DIMM_B1 (for two sticks), and DIMM_D1 forone.  From 11 Jan 2017 at 8:59am  post

<http://forum.asrock.com/forum_posts.asp?TID=4217&PID=22004&#22004>

I'm deeplygrateful for forum and tech support - yet it seems that a few basic manualclarifications could prevent a lot of confusion and conserve valuable time. 

MYBREADBOARDING DETOUR

As mentioned above, I had already taken the breadboarding steps recommended by @jsc <http://www.tomshardware.com/forum/262730-31-breadboarding>  Despiterepeating the breadboarding steps after multiple deep overnight resets, Iremained 'stuck' at Dr. Debug code 99?¦until I questioned the troubleshootinginstructions.

Mybreadboarding sequence, (w/ ASRock X99 TaichiDr. Debug LED codes).

53: Problem related to memory. (Ire-installed the CPU & HSF (no visible bent pins on mobo)). Got 53 again.

Q: Doesthe fact that I did NOT get 55 indicate a problem?  "55: The Memory could not bedetected. Please re-install the memory and CPU. If the problem stillexists, please install only one memory module or try using other memorymodules."

I added one stick of 2133MHz DDR4 memory on the QVL (specifically, Crucial 4GB 288-Pin DDR4 SDRAM DDR4 2133 (PC4 17000)Desktop Memory Model CT4G4DFS8213). Then get Debug code "d7: The Keyboard and mouse could not be recognized.Please try re-installing the keyboard and mouse."

  So Iplugged in the USB keyboard and mouse.

Got

"d6: The VGA could not be recognized.Please clear CMOS and try re-installing the VGA card. If the problem stillexists, please try installing the VGA card in other slots or use other VGAcards"

 

ClearedCMOS, using the CLR CMOS jumper and removing the battery (for 10min??.
Installed three different VGA cards
Each time I got code 99. Both with andwithout the monitor connected to the card.
 

1.Videocard from a Dell XPS, ATI Radeon HD3650 (PCI-e 2.0 x16, uses onboard power).  Got code 99.
 

2.GTX9800(6pin power connected) Got code 99.  Then when retried after the Radeoncard, got stuck at d6 (had cleared CMOS prior, but might not have waited quite10 minutes?¦what? Try again. oops. had unplugged both ends of the power cord). Now stuck at 99 again.
 

3. GTX1070 (8pin power connected).  Code 99

(Added keyboard and mouse prior to graphics card, to get past code d7) Stuck at 99 again.
 

Debug codes "92-99 Problem related to PCI-Edevices. Please re-install PCI-E devices or try installing them in otherslots. If the problem still exists, please remove all PCI-E devices or tryusing another VGA card."

Debug code 99? Specifics anyone?
No.

I had not proceeded to connect drives - because the codes kept tellingme that there was a problem. And the forums kept telling me to strip thingsdown to basics, without any SATA or M.2 devices.

Should I?
Why not?

 

Connectedthe SATA SSD to SATA3~0. Rebooted. Got to codeA2

 

Connectedthe SATA HD to SATA 3~0. Rebooted. Got to A2.

"A0-A7: Problem related to IDE or SATA devices.

"Please re-install IDE and SATA devices." Did that. Still got A2.

"If the problem still exists, please clear CMOS and try removing all SATAdevices."  Back to 99

Connectedthe SATA SSD to SATA3~2. Rebooted. Got to codeA2.
 

Re-connectedthe SATA SSD to SATA3~0. Rebooted. Got to codeA2.

Decided to ignore the 'problem' and connect themonitor anyway.
Debug says A6. Yay?

A6: Problem related to IDE or SATA devices.Please re-install IDE and SATA devices. If the problem still exists, pleaseclear CMOS and try removing all SATA devices.

Decidedto continue ignoring the 'problem' code, andkept devices installed. Rebooted, this time hit F2.
 

GOT TO UEFI.

*Deepthanks to @James999 for his post:

"This is bizarre, because it is contradicted by the(extremely brief) section in the manual on error codes.

If the errorcode is steady on 99 after power up, the BIOS will load.  (with 1 or 2 sticks of RAM).

"So bottom line, I think Dr. Debug code 99 is not actually anerror. I think it indicates that the final step of boot-up has finished and theBIOS is loading. One additionalitem: on both boards, with one stick of DDR4, you will not get to the 99 codeunless the memory is in a particular slot. It was different on each board whichslot worked. I had to use trial and error to findthe right one on the ASRock board because the *&#^% manual does notindicate which one to use first."#9James999, Jan18, 2015  <https://forums.anandtech.com/threads/error-code-99-asrock-x99m.2417200/>

*Thanks to @parsec for clarifying " Thecodes do not identify an error, they simply identify each POST test/procedure??/span>IF a POST code is shown on the Dr Debugdisplay, and it remainsdisplayed, that means that particularPOST test failed for some reason??  From @parsec's 02Jul 2016 at 11:20pm post here<http://forum.asrock.com/forum_posts.asp?TID=2966&title=fatal1ty-x99x-killer-problem-starting-up>  Note that in my case -- that word 'failed' kept me in a breadboarded looptroubleshooting 'error' codes without my peripherals attached. 

*Despitethe manual, that says "Dr. Debug is used to provide codes that representdifferent errors that your system has encountered. Please see thediagram below for reading the Dr. Debug codes and how totroubleshoot." 

Thanks also to @DJViking for sharing the sequence of POST tests on anX99 board.  <http://forum.asrock.com/forum_posts.asp?TID=2966&title=fatal1ty-x99x-killer-problem-starting-up>

Post edited by DJViking - 02 Jul 2016 at 1:55am

Very useful general guidance for newbuilders:

+STICKY: PERFORM THESE STEPS before postingabout POST/boot/no video problems!

<http://tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems>

That sticky also suggests:

"...jsc's breadboarding thread:

http://www.tomshardware.com/forum/262730-31-breadboardi...

(see my BREADBOARDING DETOURnotes below.)
 

If you make it through the entire checklist without success,Proximon has put together another great thread with a few more ideas here:

http://www.tomshardware.com/forum/264823-31-progess-tro...

More about : performsteps posting post boot video problems"

+Build guide from Paul's Hardware <https://youtu.be/XQEwQ-sRUZU>  (via @Xaltar, <http://forum.asrock.com/forum_posts.asp?TID=3599&title=build-guide-how-to>)

MYBREADBOARDING DETOUR

I turnsout that I had already taken the breadboarding steps recommended by @jsc <http://www.tomshardware.com/forum/262730-31-breadboarding>

Despiterepeating the breadboarding steps after multiple deep overnight resets, Iremained 'stuck' at Dr. Debug code 99?¦until I questioned the troubleshootinginstructions.  See next post... 

Heystookie72 - sorry you're having a similar experience. ptsd déj? vu!  

Take adeep breath - you might be in the home stretch!

Maybeyou'll need to do more troubleshooting to find YOUR obstacle.  Yet before you do, you might try somethingsuper fundamental.

I took many detours to around the 'Error' code 99 roadblock. How I FINALLY* gotto UEFI? 
 

• Recognized (thanks to @James999 and @parsec)* that the Dr. Debug codes are NOT 'error' codes, but rather mal-documented post process codes.

• Acquired 1 stick of 2133MHz DDR4 memory on the QVL.

• Reconnected my devices.

• IGNORED the 'error' code, and kept devices installed.
• Rebooted, this time hit F2.
   

GOT TO UEFI!!

~~~~ more naïve n00b saga excerpts below ~~~~

I think my post was too long -- got 500+Chinese characters again, so I'll try this in chunks. 

Received 1 stick2133MHz QVL-listed RAM as recommended by @parsec*, and tried it in D1** andA1***, clearing CMOS between, but still stuck on 99.

Alsotried 1 stick in each of the 8 slots, clearing CMOS between.

@parsec: *"Some cheap DDR4 memory I can guarantee will work in your boardis the Crucial model below. I've used it with my ASRock X99 board, and ani7-6800K:

http://www.newegg.com/Product/Product.aspx?Item=N82E16820148856"

Crucial4gb DDR4-2133 UDIMM 1.2V CL15, CT4G4DFS8213

• One stick in D1** per X99 memory config, population priority diagrams shared by @wardog, this thread.
• One stick in A1***, implied by the Taichi manual, and as the ASRock TSD explicitly instructed  Zachary:

ManufacturerResponse:

Dear Zachary,

We sincerely apologize for anyinconvenience this may have caused you. 

Please trouble shoot themainboard whether the issue is resolved.

If problem still persist, checkthe last code that shown on the board to report us when contacting techsupport.

??Unplug the ATX power, removeall components from mainboard.

??Remove the mainboard fromchassis, place it on mainboard?�s box.

??Clear the CMOS.

??Reseat the CPU and heatsinkfan.

??Test with single memory moduleon Al slot.

??Reseat video card firmly and6+6 PCIE power (if applied).

??Connect the monitor.

??Plug the 24 + 8 or 4 pins ATXpower.

??Connect the chassis powerswitch to mainboard.

??Turn on the power to check ifits post.

If you have any technical supportinquiry, please contact us at http://www.ASRock.com/Support/tsd.asp

We will assist you shortly.

Thank you

ASRock Support

Tech Support Email: http://www.ASRock.com/Support/tsd.asp

From <http://www.newegg.com/Product/Product.aspx?Item=N82E16813157719&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-PCPartPicker,%20LLC-_-na-_-na-_-na&cm_sp=&AID=10446076&PID=3938566&SID=>

I've done everythingsuggested in  ASRock TSD's list ofinstructions to Zachary.  Still stuck on99.

I've alsodone everything suggested on this most excellent post "PERFORM THESE STEPS before posting about POST/boot/no video problems!"

<http://www.tomshardware.com/forum/261145-31-perform-steps-posting-post-boot-video-problems>, except:
 

• #17. My board does not have a system speaker - however it does have the Dr Debug LED.
• #22, I need to try DVI still. I've tried HDMI and VGA so far.  (22. If you have integrated video and a video card, try the integrated video port. Resetting the bios, can make it default back to the onboard video. (AFAIK, the Taichi has no onboard video). If you are trying to use HDMI outputs, try using DVI or VGA instead. Sometimes the HDMI ports won't work until the correct drivers are installed.)
• Also, I've not checked voltages on my PSU, but it's not dead - the fans whiz and lights glow - and I didn't exactly cheap out on it. (SeaSonic PRIME 750W 80+ Titanium Certified Fully-Modular ATX Power Supply)
• I have not yet gotten to these additional threads:
   
• jsc's breadboard
  
  Edited by 22curious - 15 Jan 2017 at 1:18am]]> Fri, 13 Jan 2017 21:17:59 +0000 https://forum.asrock.com/forum_posts.asp?TID=4217&PID=22129&title=asrock-taichi-debug99-never-posted-n00born-build#22129 https://forum.asrock.com/forum_posts.asp?TID=4217&PID=22128&title=asrock-taichi-debug99-never-posted-n00born-build#22128 Author: 22curious
  Subject: 4217
  Posted: 13 Jan 2017 at 9:14pm
  
  Last two times I've tried to post, I get 500+Chinese characters? This is a test.]]> Fri, 13 Jan 2017 21:14:09 +0000 https://forum.asrock.com/forum_posts.asp?TID=4217&PID=22128&title=asrock-taichi-debug99-never-posted-n00born-build#22128 https://forum.asrock.com/forum_posts.asp?TID=4217&PID=22046&title=asrock-taichi-debug99-never-posted-n00born-build#22046 Author: 22curious
  Subject: 4217
  Posted: 12 Jan 2017 at 8:45am
  
  Well, I tried my friend's GTX 9800 on my out-of-case stripped down build.  No joy in Taichiville.  Still stuck at 99. 
  ]]> Thu, 12 Jan 2017 08:45:01 +0000 https://forum.asrock.com/forum_posts.asp?TID=4217&PID=22046&title=asrock-taichi-debug99-never-posted-n00born-build#22046 https://forum.asrock.com/forum_posts.asp?TID=4217&PID=22045&title=asrock-taichi-debug99-never-posted-n00born-build#22045 Author: 22curious
  Subject: 4217
  Posted: 12 Jan 2017 at 6:14am
  
  Short straws (contact pins) are intentional?
  
  So it finally occurred to me that I should conduct a closer examination of my GTX1070 board,  and found two contact pins that are not as long as the others.  As I was on my way to imgur to set up an account to post my pictures of this disturbing discovery...I did a quick search and found that these short straws are apparently by design, according to 
  <http://superuser.com/questions/1030382/broken-connectors-pins-on-graphics-card>.
  My short pins are in the same places described therein.
  
  So this is both re-assuring and disappointing, because I thought maybe I'd found the dysfunction leading, inexorably to code 99.
  
  While rebuilding outside the case, it seems that the graphics card is sloppy in the slot, lacking the case support.  Is this normal?  The lock did flip up and clicked, and would go no further as it's against the edge of the massive GPU unit.
  
  ]]> Thu, 12 Jan 2017 06:14:32 +0000 https://forum.asrock.com/forum_posts.asp?TID=4217&PID=22045&title=asrock-taichi-debug99-never-posted-n00born-build#22045