Hi, all
I just wanted to give you a half-time update.
BUT let me say this first, AND it is said already various times:
KEEP IT SIMPLE. Set a goal of what you want! And of what you are capeble of.
if it is just a display that you want -> just do that.
In my case; I am very handy and have basic understanding electricity/PC building. That means; I can put parts together but don’t ask me how to build parts (however I can copy).
After a lot of reading, watching videos and research I had set my goals:
(if possible of course. Never opened an iMac myself)
- 5K display
- Internal PSU
- Original iMac fan
- Original speakers
- Reuse original USB ports ethernet
The parts I used are named in earlier posts so I will not repeat that.
Building/preparing:
1st problem: It is hard to find parts in this 5th biggest country they are or super expensive or need to be imported (high taxes).
After I had cleaned out the iMac case the 2nd problem was placing the USB hub(s) and USB C adaptors. This meant that the ports needed to be altered. My Dremel came in handy, but it is a slowly process. Trying, sanding trying sanding. I slipped a few times damaging the case a bit. I still don’t get it how Aiwi got it done, but I had not the space and so the adaptors came out a bit. Even so the Hub I bought had the same distances as the original USB ports I needed to make the slightly bigger so the two C ports of that hub could be reachable. I got the ethernet in place with a lot of difficulties (see remark later)
The 3rd problem arose quickly; this PSU has a Manual voltage 115/240v selector! As we have here both the voltages next to each other, I needed a solution for that; an automatic voltage PSU (could not find one that fitted) or replace the selector. YES, I had contact with an electrician regarding replacing this selector! DON’T do this if you have only one voltage system.
4th problem; I could not fix the PSU to the case rather than (metal) glueing. That would make replacing impossible. So, I decided to tear the PSU down, added heatsinks and altered the original HDD holders so that the PSU board sat below the high line. Perfect fit and the 2 side heatsinks also touched the holder for extra heat flow. The PSU fan I removed and fixed it to the case connected with a separate PWM controller.
For both fans I used a DC-DC stepdown 24v to 12v.
The PWM controller for the original fan I wanted to be in a place where I could easily alter values. So, I placed it above in the RAM opening. The sensor I fixed on the heatsink of the display board.
The other DC-DC stepdown is for extra power for the USB hubs.
ALERT!! Check and recheck polarity. I made the stupid mistake and blew up some DC-DC step-downs before I realized I had connected the wires wrong on the PSU. (reading upside down is difficult)
For the 5K display board I reused/replaced the original board holders. It was a bit hard to get it in a good place so that cables could run beside it.
SPOILER
After putting al together and doing a test …..I had NO DISPLAY signal, …. NO USB ports connection…… what the heck!?!?!? Tested the display board again with a direct cable and it worked both C and DP. ?????? Lost my mind. Disassembled all and checked connections; all good as far I could see but testing showed otherwise. So. Now cable by cable testing….. and yes found the problem… seems that if you use too many cables/adaptors the chain stops after the 3rd connection. Weird but true!
M4 mini - Tb4 cable – Tb4 90º adaptor – tb4 female/female adaptor - tb 4 cable – board = NO GOOD!
HMMMM! I had no Tb4 male/female cables, so I ordered them. Hoping taking the female/female adaptor out resolves the problem. Fingers crossed. I hope I get my C port case connection back.
Regarding the internal hub I had to replace the hub, so I had to give up the ethernet port. All that work for nothing! But I think now it was not necessary at all.
DP and HDMI cables: I will connect the DP cable to the board and send the cable trough the RAM door, rolling the cable behind the iMac case. Just as reserve (windows) connection. The HDMI unconnected, it is reachable in case of need.
What is missing is the crossovers (and amplifier). This due a misunderstanding with StoneTaskin. After rethinking I opted to add a Bluetooth amplifier and skip the connection by the display board. It makes the system more multipurpose.
Waiting time for the last parts. 4 weeks. Will test more meanwhile.
For now I am very happy with the build.
