So I’ve taken over for a friend. Trying to get his son’s PS4 back and running again.
The original issue was just simply to change the APU paste and he replaced the CMOS and cooling fan. After that it wouldn’t boot or anything.
So I’ve taken over. I’ve looked over this entire console. I can’t figure out the issue?
I’ve tested the PSU voltage, changed the 4-pin cable from PSU to the board, checked the pin connector on the board and I can see all four making contact, checked the actual power button on the board, checked all the ribbon cables and connectors, put the old fan back in and tried to boot again… everything I can think of. I can’t get anything???
What am I forgetting to check?? What should I do next???
Was it running before your intervention?
It was only running before his work, never have I personally had it running. It just sounded like it was running too loudly and inefficiently, so he describes. Then it stopped for him. I did disassemble of my own PS4 to compare, as they are identical model numbers. I tore mine down, did a repaste, compared all the parts and then put them back together(trust me no parts were confused with each other lol). And mine has continued to run like a champ… no idea what he did, but it really doesn’t look like much. There was only a slight crimp on the 4 pin power cable that prompted me to maybe replace it. It was so cheap and I figured it might be holding the power back to the board… to no avail…
are you trying to turn it one by the plastic button (assembled)? have you tried to touch directly the button on the motherboard? have you tried to turn it on inserting a disc? have you tried with a working power supply (could be your ps4 power supply)?
I didn’t swap the actual PSU, but I tested its voltage out, it’s getting and holding 11.9 from its main two rails… so I’m a little hesitant just throwing another one in, when it’s holding power correctly and sending out to the board correctly.
I’ve tried the actual button on the board and it’s fine, and yes I’ve tried with a disc and ejecting it and trying other ways to power it on.
Totally stumped by this system? Lol but I’m not giving up yet!! I really appreciate the help! 
did u check the circuit of the 4 pin (5 volt) connector on the board? some times when this 4 pin cable is removed for first time is pretty tight and you can rip off this connector or even cause damage to board…
also check caps around that area looking for a short…
Yeah man. I don’t mean to say this anyway other than just a heads up, all these questions I answered in the first post my friend.
some times the simpler step is the one we forgot and that’s the solution, i’ve learned about this that double checking is never too much, and there is not a guideline to solve a problem… after saying that… if i were in your shoes, i would start doing random testing… by the way, which console version is it?
haha sorry, i just saw the version on the topic
this version has a push button that usually fails, but as you said you already have checked this one, i guess it closes the circuit perfectly when you press it… so, i guess i’m not helpful this time…
You’re totally correct!!! I’m totally just making sure my original information came through, as it should have. Even if I was perfect at everything, I know it’s often the simplest fixes staring right at us the entire time. I have had this for about a week now and between that I’ve very slowly gone over piece by piece. Assembled multiple times slow as hellllll to see if I’m missing ANYTHING. I’ve been trying to understand what can stop a boot versus what boots into safe mode. I’ve thought about this problem till the cow comes home, so I definitely am at that stage where the obvious starts to blur.
Model- PS4 CUH-1215A
PSU - 4-pin, ADP-200ER
Anything else? I can open it up and take more pics, but I can’t post them here, so I can email em or send em anywhere. I do have some pictures of the actual power port on the mobo itself, already labeled too(I sent them to the original client who knows very little so I labeled it for him haha).