Full solution can be found here:  http://forum.asrock.com/forum_posts.asp%3FTID=9764&PID=56644&title=ab350-pro4-no-post#56644" rel="nofollow - http://forum.asrock.com/forum_posts.asp%3FTID=9764&PID=56644&title=ab350-pro4-no-post#56644

----------

Hey guys, new to forum and new to PC building. This is my first rig but I've been around computers my whole life and understand quite a bit in regards to building computers. I've repaired damaged components and even upgraded and flashed computers for the military. That being said, I'm savvy but far from perfect.

I finally got all my parts in today and with my work schedule didn't get a chance to install them until ASRock had closed for the day. I spent the last several hours troubleshooting and attempting to figure out what's going on that I can't get this machine to POST.

The PC turns on, I get a Power LED indicator, the CPU and chassis fans spin up for about a minute, then the system power cycles, indefinitely with no display.

First, I'll include my hardware list, then I'll cover the troubleshooting tips I've tried.

Parts:
Motherboard: ASRock AB350 Pro4 Rev 1.03 (Ryzen 2000 Series Ready)
CPU: Ryzen 5 2400G
PSU: Corsair VS550 550W
RAM: Corsair Vengeance LPX 16GB (2x8GB) 3200Hz
CMK16GX4M2B3200C16
DIMM Slots A2 & B2
Case: Corsair 200R
Storage: ADATA 256GB SSD
Western Digital 1TB HDD

Everything was originally plugged into the MoBo when I first turned it on but have since disconnected almost all case and storage plugs on the motherboard. This board has no LEDs or buzzer so troubleshooting has become incredibly difficult.

The board specifically shipped with the Ryzen 2000 Series Ready Sticker on it and was promised that indicates it should work the new APUs as well, including the 2400G I'm using.

The RAM modules are not only listed on the Raven Ridge QVL, but they are also supposed to run at their listed speed with no issues. If you missed it above, they are installed into the priority slots (A2 & B2). I have tried removing both, reinstalling, trying different slots as well as trying only one stick. No changes in behavior.

I have unplugged and plugged the 8pin (4+4) CPU power connector back in (specifically marked as the CPU power connector on the cable as well) and did the same for the 24 pin cable. I ensured that both are completely down with no gaps.

The APU literally fell into its socket with 0 force. Once the bar was lowered, it did not move an inch. The fan installed relatively easily minus a bit of sliding while attempting to secure it to the back plate.

The RAM modules make a sort of velcro or zipper sound when installing, but I hear an audible click from the "fixed" tab, then continue to press in the non fixed tab which also clicks and closes by itself. The RAM doesn't move once installed and both clicks are heard regardless of stick or DIMM slot.

I have 2 different monitors, which were purchased new recently and verified to be good prior to installation. I have tried VGA, DVI, and HDMI. No changes in behavior.

I have tried resetting the CMOS a few times as well.

Im seriously at a loss here as the only thing I can't verify is that the MoBo actually supports my APU. Please, if there is any support you can provide, I'd be ever grateful. I do plan on contacting ASRock eventually, but work prevents me from doing so as I'm on the other side of the nation and work the hours they're open. Will also try any ideas you can think of and provide any necessary pictures or other details.

Edit: Clarified the use of the 4+4 CPU power connector.

Edit 2: Added RAM Model Number.

First up, great post, you listed your specs, what is happening and what you have tried already in a very clear and easy to understand way, thanks.

Power cycling on Ryzen systems is almost always memory related, either the RAM is not supported or the CPU IMC isn't being correctly identified (CPU not supported). Given your symptoms and specs the first thing to check is the sticker on your BIOS chip. It isn't always replaced when boards are flashed post production but if it was it will help rule out CPU support. If the sticker states an old BIOS version (pre 4.xx) then the next step is to check if the serial number on the board matches the one on the box. Sometimes returned boards get put into the wrong box and resold by retailers, this can lead to a "Ryzen 2000 Series Ready" labeled board not actually supporting the new(er) APUs.

If that all checks out then the next thing to look at is RAM. I see you have already tried one stick but you did not mention if you tried it in each slot. If you have not already go ahead and try each module, one at a time, in each of the slots and see if you get post with either. Checking your RAM on Corsair's website does not list support for any AMD platforms. That doesn't strictly mean it isn't supported but it does mean Corsair have not verified compatibility themselves. Another issue is that RAM manufacturers will often "update" RAM models with different RAM chips and a new revision will not necessarily be compatible with an older one. When they run out of a particular RAM chip they frequently can't get the same chips in again and have to change to another type or brand.

RAM specs from Corsair website: https://www.corsair.com/uk/en/Memory-Size/Tested-Speed/vengeance-lpx-black/p/CMK16GX4M2B3200C16

Note only intel is listed as supported.

It is encouraging that the kit is listed on the Raven Ridge QVL but that only means it is compatible with the CPU IMC, not necessarily the motherboard. 

AB350 Pro4 memory QVL: https://www.asrock.com/mb/AMD/AB350%20Pro4/#Memory

Click the drop down tab under "Vendor" and select Corsair to narrow down the list and you will see your RAM is not officially supported on this board. That said, I have noticed that most manufacturers do not update these lists very often and ASRock is no exception, you may require a newer BIOS to support it.

I hope this is of some use to you, good luck and post back with your findings 

That RAM is rated at 1.35v, try setting the voltage manually to 1.35 with the working stick installed (no other changes) then power off and install both sticks in A2 and B2 and see if they will work then. You could also try updating to the latest BIOS version for your board (5.00 I believe) and see if that gets you going. If not, return that RAM and get something different. 

RAM and Ryzen can be a real PITA but once you get it working Ryzen is great value. 

Be sure you have reset to factory defaults before flashing and use the instant flash method as it is the safest.

Sorry about that, I totally missed that there is a second qvl explicitly for Raven Ridge. It does appear you got a defective kit, it seems to be all too common these days, you are the second case of this I have seen on the forums in the last 2 weeks.....

I know quite a few people that swear by G.Skill for Ryzen, most particularly the Flare X Series that are apparently designed specifically for Ryzen:

https://www.gskill.com/en/press/view/g-skill-announces-flare-x-series-and-fortis-series-ddr4-memory-for-amd-ryzen" rel="nofollow - https://www.gskill.com/en/press/view/g-skill-announces-flare-x-series-and-fortis-series-ddr4-memory-for-amd-ryzen

Not living anywhere where newegg delivers I have never had any experience with them but generally I haven't seen too many issues with them on the forums here and other Tech forums. 

Most likely it's a DOA RAM or just a compatibility issue.

I'm one of the guys who swears by G.Skill for Ryzens. As is half the Internet. :D Flare X is a beast, especially for an APU where mem bandwidth is critical.

Since you mentioned the navy, do you have some spare ICBM in your garage maybe? Willing to trade it for a pair of Flare X. You know, I promised the daughter a big firework party and I hate to disappoint.

Newegg got a bit soft after the recent hack, so that's to be expected.

Ryzens on the other hand were quirky only with their first generation. Next one has really improved memory controller and are definitely not that picky when it comes to RAM.

What' you're seeing as a quirk with Ryzen can easily be an issue with the mobo itself. Just do a quick search for ABx50 in this forum, sit back and enjoy.

If your new Corsairs run fine at their advertised speed I guess a pair of Flare X would not warrant its price. Besides, I doubt you're running that much of performance-critical apps.

Faulting application name: PathOfExile_x64Steam.exe, version: 0.0.0.0, time stamp: 0x5bac3be8

Faulting module name: atidxx64.dll, version: 24.20.13019.1008, time stamp: 0x5baafb30

Exception code: 0xc0000005

Fault offset: 0x00000000000a2e68

Faulting process id: 0x1d80

Faulting application start time: 0x01d457bfb4f3694a

Faulting application path: C:\Program Files (x86)\Steam\steamapps\common\Path of Exile\PathOfExile_x64Steam.exe

Faulting module path: C:\Windows\System32\DriverStore\FileRepository\c0333764.inf_amd64_239226e8c322a98d\B333740\atidxx64.dll

Report Id: 7dbaa744-370c-4d9c-aab1-fbf05b5e8592

Faulting package full name: 

Faulting package-relative application ID: 

After doing some research, it's a DirectX DLL and that the most common issues is with Anti-Aliasing. They typically said that games weren't stable when using better AA and that you would need to turn it down or off to prevent crashing. AA was already off in PoE (!) but I said let's try it and enabled 2x MSAA. No more crashes but frame rates were all over the place, constantly dropping down to 30 FPS in simple areas with no combat. This was unusual but acceptable for me as it didn't crash.

Moving forward, my friend suggested that using AA to combat the crashing isn't the correct issue and recommended lowering the clock speed. After considering what I felt was an acceptable speed of 3000Hz @ 1.35V, we decided to put it through it's paces. We gamed heavily all day Saturday without a single crash. He was definitely on to something. I wasn't quite happy with that by itself and wanted to see what other settings might need to be changed to get 3200Hz to work. We discussed a bunch of different possibilities and looked at all of the XMP values. They can be found here (Abbreviation: Value w/o XMP -> Value w/ XMP -> Value of Auto @ 3200Hz (optional)):