[DoughnutVan]

6. Remove The Head Unit Cover (Continued)

Note that the cable on the bottom has it's retaining clip on the top, so squeezing the top and bottom of the clip is optimal and should be easy.
The warning lights cable however has it's retaining clip on the left side, note it's location in the following image.

The head unit cover should now be free and disconnected, it can be set aside.

7. Remove The Radio/CD Drive Unit

Unscrew the two T25 Torx screws on the left and right of the radio. Once unscrewed, the radio should slide right out. There are two cables on the back that can be easily unclipped. The radio should now be free and can be set aside.

8. Remove The Screen/Radio Unit Retaining Cage

There are four screws on the left and right of this cage that will need to be removed. Be careful not to drop these as they could easily be lost in the center console area.

Once unscrewed, there are clips on the upper left and right and lower left and right. As you tug outwards, these will be un-clipped. The upper clips cause the most snag, the lower clips are supplemental (Upper right un-clipped pictured below)

Carefully slide out the cage, minding the cables connected to the APIM unit behind the screen. The upper "blue" cable has a retaining clip directly below it, this may require plyers depending on the person.

Finally, undo the gray clip on the large black cable. Push down on the clip in the middle to release the gray clip.

Once the gray clip is released, it should rotate to disconnect the large black cable.

There is also a USB hub cable connected to the passenger side of the large black cable (This is not pictured, but is disconnected in the below image). This has a retaining clip on it that can easily be removed.
All three cables connected here should now be free, and the entire cage can be removed.

(Further Steps TBD)

 

[DoughnutVan]

NOTE: From here, the Head Unit has been removed. If this is all you needed, you can stop here, and follow the steps in reverse to reassemble if needed.

9. APIM Disassembly

With the cage removed, lay the cage with the screen face-down on a smooth surface to reduce the potential of damaging the screen. Remove the blue side of the blue and yellow cable, this connects the screen to the APIM unit. (Don't mind me breaking part of the blue cable's casing, lol. Be more careful than me, I guess)
With the blue cable unplugged, unscrew the three Philips head screws around the edge.

Note: If you're just replacing the APIM and not doing anything further... You can stop here and return from whence you came to reassemble.
Additional Note: There are capacitors as you go further. Generally speaking, these can lead to electrical shock or worse. Be cautious if you don't know what you're doing!

Flip over the APIM unit and unscrew the seven Philips screws around the edge. Once unscrewed, remove the metal cover.

The APIM unit's main board should now be visible. If you wish to remove it, firmly press on the "Press Here" printed image to release the board connector. The black shroud covering the WiFi radio slides off.

Here's the other side of the main board

Last but most certainly not least, unscrew the four screws on each corner of the daughter board, housing what I can only assume are the main processor and memory... I could be wrong though.

And a glamour shot with and without the thermal pads.

Done! Follow the steps in reverse to completely reassemble.

 

[DoughnutVan]

Of course, I should add I wasn't able to find why my head unit isn't working. All the resistors appeared to be fine from the naked eye and none of the capacitors looked worn or damaged from what I could tell. Cables and connectors seemed sound as well. All the other systems on the vehicle are operational besides radio/audio/head unit. For those interested, here is what is happening since the deep freeze.
-The ST has largely sat in the garage while I drive my second car since the head unit stopped working consistently.
-The radio no longer saves my general settings like day/night theme or 911 assist, but saves my bluetooth devices that have previously connected.
-The head unit will sometimes not power on upon door opening (I suspect this may be due to an old battery, so I may just be stupid, lmao.). I should note that the head unit will work after I've been driving for a bit, shut off the car, leave (running errands or work, whatever), and come back to it. I suspect the battery has had time to charge enough from the initial drive to power the head unit...
-Apple CarPlay no longer works upon USB connection.

EDIT:
A good friend also reminded me about the BMS cable which I had noticed when disconnecting the negative terminal. When all of this started happening, the negative battery terminal was pretty badly corroded, so I will look into replacing the BMS before replacing the battery altogether... Although I do need a new battery anyway.

Edit 2:
After looking into a post from @SSgtjrobertson on the BMS, I'm fairly positive that a good first step will be to replace the negative cable.

 

[DoughnutVan]

Damn that was detailed! Thank you for that info. That’s some impressive work my friend. BTW, what kind of camera did you use? Those pics are crystal clear

Thank you!! I'm glad to hear it. I used my iPhone to take the pics, I'm glad those came out well, too!

 

[DoughnutVan]

To keep this thread updated on the status of the head unit, it unfortunately still isn't working after I got a new battery installed, replaced the negative wire to the battery, and reset the BMS. Speaking of the BMS, luckily I ran into this thread, which was a huge help in finding out that I had my wires backwards (The windshield wipers stopped working). I made sure that the battery got a good charging earlier in the week in case it was a power issue and checked fuse 67 for the Sync system with no luck on either approach. Maybe there's another fuse that I should be checking? Not sure. Either way, I'm afraid I may be looking into taking my head unit apart again, either to take a closer look, make sure I plugged all the wires in fully/correctly, and... to potentially replace something...

 

[DoughnutVan]

I figured I'd finally update this thread. I've done a little bit more digging with my broken head unit with no luck. Unfortunately I had no luck contacting Brian Lovelace either, hopefully all is well with him, otherwise I'd have gone through him in this case. In light of that, I decided to buy a refurbished APIM as an initial step in beginning to fix this. I decided to do this so that I could retain most, if not all, of the original head unit's functionality... Mostly just preference on my end and I'm willing to invest into that creature comfort.

It pained me to do it, but at the end of the day, I suspected that it may have been an APIM failure...And hey, if it isn't the APIM, then I'll have a spare! I expect to get the APIM I ordered sometime next week, so I plan to update this thread on whether or not that was the solution. If it was indeed the APIM that failed, I'd like to tear it apart further to figure out exactly what may have failed!

 

[DoughnutVan]

Well, my suspicions were correct that the APIM had failed. This morning I replaced the old with the new and spent the rest of the day making sure the new one worked correctly (it does so far). In any case, I learned how to replace the negative battery cable and learned how to get my hands dirty with the head unit. I should also note that I updated the above posts with the correct Torx bit size. I originally said T20, but it's actually T25. Here's the newly working head unit after this journey and here's to many more years with this awesome car.