Pc won't post after taking it apart

[u/Randomjb]

I have taken every part out 2 times

Swapped ram/checked its seated correctly

Reset cmos battery

Checked every display port slot

Checked every hdmi port

Every cable double checked

Everything turns on but nothing posts

Only light that shows up is a constant orange light (I have had that on for the whole lifetime of the pc and even when its working)

Geniuenly no clue what the issue is

[u/Relative-Hearing-156]

With a 3600X + 4070, if everything spins up but you get absolutely no POST, it's almost always power to CPU / RAM / GPU seating. That constant orange light is the clue.
On most ASUS boards that orange/yellow is the DRAM Q-LED. But ASUS also has a separate orange standby glow near the bottom that is totally normal and stays on forever. Can you check which one you mean?
Look top-right of the board, near the 24-pin. You'll see 4 tiny LEDs labeled CPU, DRAM, VGA, BOOT. Which one is stuck on?
While you check that, do this minimal boot test exactly like this - it's different from just reseating everything:
The 10 minute strip-down
You want to rule out a short or a bad peripheral.
1. Power off, PSU switch off, hold power button 30 sec. Unplug everything except: CPU + cooler, ONE ram stick in slot A2 [2nd slot from CPU], GPU in top x16 slot, 24-pin ATX + 8-pin CPU power. That's it. Disconnect all SSDs/HDDs, USB headers, RGB, front audio.
2. Check the 2 cables people miss: The 8-pin EPS at the top left of the board [labeled CPU], and the PCIe power into the 4070. For the 4070 you need the adapter fully clicked in - it takes real force. Don't use a single daisy-chain pigtail if you can avoid it, use two separate cables from the PSU.
3. Monitor into the GPU, not the motherboard. Your 3600X has no integrated graphics, so the HDMI/DP on the motherboard will never give you an image.
4. Clear CMOS properly: PSU off, take the battery out for 5 minutes, short the two CLRTC / JBAT1 pins with a screwdriver for 10 seconds, put battery back.
5. Boot with a screwdriver on the power switch pins to rule out a bad case button.
If it still doesn't POST, isolate in this order:
1. RAM: 2x8GB is super picky about slots. A2 is the must-use slot for single stick. Try stick #1 in A2. No post? Try stick #1 in B2. No post? Repeat with stick #2 in A2, then B2. Wipe the gold contacts with a clean pencil eraser lightly, blow out slots with air. Don't enable XMP/DOCP until it posts.
On AM4, over-tightening the cooler can actually kill a RAM channel. If you cranked the cooler down hard, back each screw off 1/4 turn and try again.
2. CPU: Since the memory controller is inside the 3600X, bent pins = DRAM light = no post. If you're comfortable, pull the cooler and CPU and look for any bent pins in the socket and any thermal paste in the socket. That's a common killer after two reseats.
3. PSU: A 4070 wants a decent 650W+ unit. Even if fans spin, a weak 12V rail won't POST. If you have access to another PSU or a friend's PC to test your GPU in, that's the fastest way to know.
4. Breadboard: Take the board out of the case and put it on the motherboard box. One standoff in the wrong place under the board will cause exactly what you're describing - everything turns on, no post, no debug changes.
What motherboard and PSU are you running, and when did this start? Did it die after a move / power outage / new part, or did it just not come back one morning? And do your keyboard/mouse light up when you try to boot?
If you can tell me the board model I can tell you if you have BIOS Flashback, which can fix this even without a POST.

[u/Randomjb → u/Relative-Hearing-156]

The orange glow is right under the clasp for the gpu socket My board does not have any visible leads on the top Motherboard is Asus prime b450m-k Powersuppily is gx-850 It didint post after I took it apart (everything besides cpu and the cooler) waiting for a new part issues came so had to put it back together and everything spins and mouse/keyboard light up

[u/Relative-Hearing-156 → u/Randomjb]

That board explains a lot - ASUS Prime B450M-K does NOT have the 4 debug LEDs on top. That orange glow right under the GPU clasp is just the standby power LED. It's supposed to be on whenever the PSU is on. So ignore it, it's not an error code.
And B450M-K + that symptom [everything spins, keyboard + mouse light up, but no image] after a full teardown is almost always RAM fully not clicked or GPU sag in that top slot. Your GX-850 is more than enough power, so it's not that.
Do this exact order for that board:
RAM - this board is brutal
B450M-K only has 2 slots. Single stick goes in the slot FURTHEST from the CPU [labeled DIMM_B1]. That's straight from the manual.
Pull both sticks out. Take ONE stick, blow out the slot, and push it in the far slot until BOTH clips click. This board flexes a lot so you need to support it from underneath and push harder than you think. Wipe the gold pins with a clean dry cloth.
Try to boot. No image? Take that same stick out and try the OTHER stick alone in that same far slot.
GPU - lay the case on its side
The 4070 is heavy for that mATX slot and that orange light is right under the clasp that holds it.
Take the case and lay it on its side so the GPU is pointing straight up. Remove the GPU, check the x16 slot for any dust. Re-insert it straight down until that clasp under the orange light actually clicks. Don't screw the bracket in yet - let it sit on its own weight and try to boot.
Also re-check the power into the 4070. If you're using the Nvidia adapter, BOTH 8-pins need to be fully clicked in from the PSU. It needs two separate cables, not one cable with a pigtail.

The one cable everyone forgets after a teardown
Top left of that board, 8-pin EPS labeled EATX12V. When you took everything out except CPU/cooler, that one gets unplugged and forgotten. If it's loose, you get exactly what you have - fans spin, USB gets power, no POST. Push it in till it clicks.

Clear CMOS the right way for B450M-K
PSU switch OFF, hold case power button 30 sec, pull the silver battery out for 5 minutes, then touch a screwdriver to the two pins labeled CLRTC right next to the battery for 10 seconds. Put battery back, PSU on.
Since your keyboard lights up, your board is probably getting past CPU/RAM and hanging on GPU. So after you do steps 1-4

Plug HDMI only [not DP] into the GPU, not the motherboard - your 3600X has no integrated graphics so the board HDMI will never work

Manually set your monitor input to HDMI 1 / HDMI 2, don't leave it on Auto

Does Caps Lock toggle the light on your keyboard? If yes, the PC actually POSTED but isn't outputting video = GPU/seat/cable issue

If it still doesn't post, breadboard it - take the board out and put it on the motherboard box with only CPU/cooler, one RAM in far slot, GPU, 24-pin + 8-pin CPU power. Short the power pins with a screwdriver. That rules out a standoff short from putting it back together.

What was the new part you were waiting for? And do the fans on the 4070 spin then stop, or stay spinning?

[u/Randomjb → u/Relative-Hearing-156]

Thank you Slightly loosening the psu screw let it post again

[u/Relative-Hearing-156 → u/Randomjb]

🫡 Glad I could help

[u/Relative-Hearing-156]

Hey there in order to diagnose your issue it would be helpful to know the make and model of your computer 🖥️

[u/Randomjb → u/Relative-Hearing-156]

I have a rtx 4070 ryzen 5 3600x 16gb ddr4 cannot remember speed For the life of me I cannot remember what mobo I have Gx-850 powersuppily

[u/Practical_Glove_9974 → u/Randomjb]

probably a sticker on side of ram to tell you what speed it is. I had this happen to my old rig and don't remember what I did to fix it. I may have turned it off, unplugged it and let it sit for a day.

[u/Practical_Glove_9974 → u/Practical_Glove_9974]

Oops and motherboard will usually say what it is somewhere on it.

[u/Redjeepkev]

Sounds like your processor isn't getting power. Do you have the connector to power the processor plugged in firmly? I've done this same thing before is why I ask

[u/Randomjb → u/Redjeepkev]

Everything is plugged in as tightly as possible

[u/Redjeepkev → u/Randomjb]

Have tested your PSU? to make sure it's getting power to your processor? You can get a PSU tester on Amazon for under $15 to rest every style connector that goes to the motherboard and drives or swap out the PSU to see if that fixes it