OP
Not just HDD, disconnect front audio, front USB ports too. If you hook any pen drives to back ports remove them too.
At this juncture the most common troubleshooting step is to try to install RAM and GPU in another slots and keep on trying a few more times. Try RAM in all possible slots one by one. Try it again and again in Slot A2. A simple loose connection somewhere might prevent PC from POSTing.
Pl. read the manual here *dlcdnets.asus.com/pub/ASUS/mb/Sock...E13723_PRIME_B350-PLUS_UM_V3_WEB_20171114.pdf
Refer Section 1.4 for optimum memory installation
Refer Section 1.2.1 sub item 14 to know how to reset CMOS and reset BIOS to defaults.
There does not seem to be any button on this board, if any would have been there, the manual would have specified so. It seems from the photo that it’s just a mounting post for the attached heat sink. Do you feel it as a button?
Recheck that all power plugs are firmly connected to CPU, GPU, Board etc
What PSU do you have? It might also be possible that it’s not supplying adequate power to the system.
However in my own observation no POSTing after some sort of maintenance may be just attributed to loose connections or slightly disturbed component installation at a preliminary level.
On this board Grey colored slots are the ones that are to be populated first (For optimum performance). Hence RAM slots A2 & B2 as well as the very first PCIex16 slot is colored Grey here!
It has two or three don't recall. Tried in all but same result. Are you referring to this-How many HDMI outs does your GPU has? I hope you are connecting thru HDMI. If more than one, did you try plugging it in another HDMI out?
If dusting has resulted into dust being displaced and again deposited elsewhere in the slots, (Especially if you don't have a powerful blower) then simple IPA cleaner spraying or cleaning the slots with soft light brush might also help.
Not just HDD, disconnect front audio, front USB ports too. If you hook any pen drives to back ports remove them too.
At this juncture the most common troubleshooting step is to try to install RAM and GPU in another slots and keep on trying a few more times. Try RAM in all possible slots one by one. Try it again and again in Slot A2. A simple loose connection somewhere might prevent PC from POSTing.
Pl. read the manual here *dlcdnets.asus.com/pub/ASUS/mb/Sock...E13723_PRIME_B350-PLUS_UM_V3_WEB_20171114.pdf
Refer Section 1.4 for optimum memory installation
Refer Section 1.2.1 sub item 14 to know how to reset CMOS and reset BIOS to defaults.
There does not seem to be any button on this board, if any would have been there, the manual would have specified so. It seems from the photo that it’s just a mounting post for the attached heat sink. Do you feel it as a button?
Recheck that all power plugs are firmly connected to CPU, GPU, Board etc
What PSU do you have? It might also be possible that it’s not supplying adequate power to the system.
However in my own observation no POSTing after some sort of maintenance may be just attributed to loose connections or slightly disturbed component installation at a preliminary level.
On this board Grey colored slots are the ones that are to be populated first (For optimum performance). Hence RAM slots A2 & B2 as well as the very first PCIex16 slot is colored Grey here!
SATA port should not matter, however depending on the chipset/CPU architecture certain SATA ports may share the bandwith with M.2 slot. So in that case manual specifies (if applicable) which SATA/PCIe ports get disabled if you install an M.2 device in the M.2 slot. However in your case from your pics it seems there's no M.2 device installed. However do refer the manual for any future expansions.
How to clear CMOS - Turn off the power. Remove power chord or put power button on back panel of PSU to OFF position. Press the Start button on front panel and keep it pressed for 15 seconds. Now using a metallic screwdriver short the Reset CMOS or Reset RTC pins for about 10 - 15 seconds. OR simply remove the CMOS battery for 5 - 10 minutes and reinsert. Now BIOS shall reset to lowest defaults.
However since basic troubleshooting has not helped and if you are not comfortable with advanced troubleshooting, I suggest you take it to a local repair shop. The guy might have spare components to check or even test it outside of the cabinet etc.
It could be as simple as dust causing poor contacts to any failed components, or even corrupted BIOS.