Contribute
Register

Buurin's first Mac build - Dumpster Flowerpot

Status
Not open for further replies.
Joined
Sep 6, 2014
Messages
34
Motherboard
Intel NUC D54250WYK
CPU
i5-4250
Graphics
HD5000
Mac
  1. 0
Classic Mac
  1. 0
Mobile Phone
  1. Android
Hello, first post, first Mac, what have I done? :p

It all started with a complete, working iMac G4 I hauled out of the dumpster in my office building. It was 15"/800/512M/60G (and the screen being 1024x768), very inadequate by any standards. But this is so pretty I just have to make something working out of it.

First, a group photo: (click, original is way too large)



Anyway, what I have on hand:
15" iMac G4
20" iMac G5 for the screen and its inverter (pulled the wifi antennas out of it as well)
20" iMac G4 native power supply
20" iMac G4 neck
LG SATA DVD burner

What I have on order:
20" iMac G4 back cover and bezel
Intel NUC D54250WYK kit

What I am going to get:
4GB of DDR3L memory
A number of short USB3 and mini-DisplayPort extension cables to run to the base
The Molex DVI-D connector DremelJunkie mentioned
A picoPSU
Assorted hardware to hook everything up

I chose the Haswell NUC because it can run Mavericks with minimal work, and CAN take 12V, eliminating the need for an upconverter. This has been confirmed at an Intel forum. The Ivy Bridge NUCs still needs 19V.

Having read much of this site and DremelJunkie, I figure I am going to run into problems.
- I only have a 15" dome. Once the 20" screen is installed it may very well tip over. There doesn't seem to be any 20" dome listed on ebay at this time.
- I'll be removing the logic board in one piece hoping to sell it off to finance the mod, so I need something to fill the space and keep the connector plates in place.
- The 15" neck has wires that terminates in the same 0.1" pitch terminals ubiquitous among PCs, but the 20" ends are much smaller. Sigh. There will be much splicing.

What I learned so far:
As I said, Haswell NUCs can be fed 12V.
My G5 screen is LG LM201W01-A5 with TMDS feed and the 20" neck just plugs right in. Sweet!

This is the inverter side pinout of the inverter wire in the 20" neck:
imacg420_invertersidepinout.jpg

Inset pic is from DremelJunkie for reference only.

Most inverters as I read have just 4 inputs: power, ground, enable, and dimmer. The yellow wire above is very likely the enable pin. I happen to have the right kind of connector laying around (had I not tossed my entire Compaq LTE5000 stock, I'd have much more at my disposal!:banghead:), so I re-pinned it from 8P to 6P, closing the gap and leaving out the purple pin. This guy then plugs into the 9mm thick G5 inverter, which I'll try to fit anyway.

The 20" neck has the right connector on screen end only, and the 15" neck has the right connector on base end only, so no simple swapping wires, and I will need to splice.

I also read about Ersterhernd's problems on artifacts. I may slip a ferrite bead over the cables in case it really is EMI interference. I got an assortment on hand.

Let (another) build begin!
 
Wow this is quiet around here! :banghead:

On hardware side, my NUC has arrived. The day before I bought a 4G stick of memory so I now have a complete NUC system to do things on. The store sold me a CL11 stick, the part number indicates a CL11 stick, but its description says it's CL9 stick! Damn you Canada Computers! :twisted:

Front panel, USB2, and that custom solution header (for which I have no hardware for) on the NUC are all 2.0mm pitch headers, but all my IDC ribbon headers are 0.1" headers and don't fit. BUT, turns out the LED/Mic/Inverter plug from the 20" neck does fit. :mrgreen::mrgreen::mrgreen:

There are also some wires from my laptop parts stash that fit this connector.

The result: a 2x5 segment cut out of that neck plug and re-pinned for the NUC.

The 20" power supply is also being rewired for two 2.5mm barrel plugs with spare leads for the screen.

On software side, two ISOs and five DVD+R DL discs later, I finally have the Mavericks installer downloaded. Borrowed my HTPC running ASUS P8Z77-M for the Snow Leopard install then going through the guides...

This coming week I'll have most fun putting together the hardware.
 
First off welcome to the club.

You have certainly chosen a complicated build, putting different pieces together from different machines. Anyway, I am not sure how much help I can be on this project, since I have actually never seem an iMac G4, but I have had experience converting an iMac G5.

One question about your build is the iMac G5 20" inverter, to power the LCD. Will it actually fit in the LCD housing? in the iMac G5 it is in the main computer (of course) and is not small !!!

I do have the pinout for the inverter, I think you have the same 20" non-isight model so assume it is the same.

http://www.tonymacx86.com/imac-mods/107859-kiwis-next-project-imac-g5-3.html#post661004

In your first post you showed a Dremel Junkie picture for the inverter, not sure why since you will be using the G5 inverter, this diagram doesn't mean much. Really its just about using an available neck wire to get the necessary power to the inverter housed in the LCD screen.

The 20" neck has the right connector on screen end only, and the 15" neck has the right connector on base end only, so no simple swapping wires, and I will need to splice.

I also read about Ersterhernd's problems on artifacts. I may slip a ferrite bead over the cables in case it really is EMI interference. I got an assortment on hand.
I would discourage splicing the actually LCD wires, they are very very thin!!, and also the signals are very high frequency so every join will cause interference and potential artefacts.

I would recommend you go with the cable for the 20" LCD and work out how to terminate it for the NUC. I know this technique works, but its not easy.

http://www.tonymacx86.com/imac-mods/107859-kiwis-next-project-imac-g5-7.html#post763190

Also a ferrite bead will not fix artefacts, what will fix it is ready good shielding around your cables. The best thing is conductive tape wrapped around the cables and connectors.

Let (another) build begin!
Keep the updates coming.

Kiwi
 
First off welcome to the club.

You have certainly chosen a complicated build, putting different pieces together from different machines. Anyway, I am not sure how much help I can be on this project, since I have actually never seem an iMac G4, but I have had experience converting an iMac G5.
And thanks for your reply. I saw this area went silent for days and thought this mod has fallen out of favor. :lol:

Yeah I figure I will run into many problems, like:

  • Getting a "gray DVD" instead of a retail SL DVD
  • Base not having enough mass to keep stable with a 20" panel on top
  • Artifacts!

One question about your build is the iMac G5 20" inverter, to power the LCD. Will it actually fit in the LCD housing? in the iMac G5 it is in the main computer (of course) and is not small !!!

I do have the pinout for the inverter, I think you have the same 20" non-isight model so assume it is the same.

http://www.tonymacx86.com/imac-mods/107859-kiwis-next-project-imac-g5-3.html#post661004

In your first post you showed a Dremel Junkie picture for the inverter, not sure why since you will be using the G5 inverter, this diagram doesn't mean much. Really its just about using an available neck wire to get the necessary power to the inverter housed in the LCD screen.
It's a "for the record" thing; I put it in my picture to show how the wire was terminated on inverter end. I have your pinout pic downloaded and have repinned the inverter end of the wire so the pinout on dome end matches and I can follow all the other guides. I happen to have just the right plug in my stash. I left the purple wire hanging.

BTW DremelJunkie said he did try a G5 inverter among something else and said there isn't enough clearance. I did some digging and measuring and found out that the aftermarket inverter he tried (looks like the ones offered by lcdparts.net) is 11.5mm thick; the G5 inverter is 9mm thick. I ordered a 20" bezel and back plate and they have yet to arrive, but I figure I'll need to cut some holes in it to make it fit, and even that may not be enough.

Finally yes I picked up a non-iSight unit.

I would discourage splicing the actually LCD wires, they are very very thin!!, and also the signals are very high frequency so every join will cause interference and potential artefacts.

I would recommend you go with the cable for the 20" LCD and work out how to terminate it for the NUC. I know this technique works, but its not easy.

http://www.tonymacx86.com/imac-mods/107859-kiwis-next-project-imac-g5-7.html#post763190

Also a ferrite bead will not fix artefacts, what will fix it is ready good shielding around your cables. The best thing is conductive tape wrapped around the cables and connectors.

Keep the updates coming.

Kiwi

Knowing I can't even properly solder a DC power plug using lead-free solder, I won't even try to actually splice anything that thin. I did resolder a set of 18AWG wires for the 12V output

My most handy source of DVI jack is on a AIW Radeon card (AGP!) that won't be used anymore, but that yields a DVI-I jack with solder on the pins after I hot-air it off. Next I'll have to turn to Digi-key.

------
More build updates

I did some googling trying to find more resources on converting G4s and found some more info from China on these "desk lamps" (ok, more like iLamps).

http://bbs.feng.com/read-htm-tid-4154130-page-1.html

This guy says he did some measurements on the G4 20" power supply and found the white ON/OFF lead can be connected to 12V via a 6.8k ohm resistor. The voltage is about 9-10V instead of 5V. Since I have a 120W picopsu clone on order, I'll link it to the picopsu's 12V output via the resistor, since it is switched, to keep the inverter off when the NUC is off, to reduce phantom power draw when the machine is off.

I test fitted some cables and found that 30cm is enough for extension cables from NUC board to the base. I'll need three USB 3.0 A-A extension cables, one mini-displayport and one 3.5mm TRRS cables for audio. Although it is easier to forget about the microphone, I still want to figure out how to keep the embedded mic functional, since the bezel/back plate I ordered would have one still attached, if the listing's pictures are accurate. That would make web conferencing that much easier.

For the ethernet jack, I'll have to hack a keystone jack (bought 10 before to upgrade the wiring in my home) and glue it in. That is relatively easy though so I'll worry about it later.

These I will not be disassembling if I can help it, maybe flattening the USB male end flange a bit so I can squeeze it through the holes and cutting off just enough plastic to have it sit flush.

While I will leave the TMDS cable alone, what I could try is to build a mini-HDMI to DVI cable. I broke apart a DVI to VGA adapter (I got too many :lol:) and got myself a solder male DVI-I plug. With the solder tabs staggered, soldering the wires one by one, I think I could manage.

What I did do though, is taped the two wifi antennas from the G5 to the dome. It bends and did get in. Unfortunately I'll have no way to test it until I get a supported wifi module, but it's no big deal.

Next: Figure out the rest of power supply wiring and how to add 1.2kg of mass to the dome.
 
Good news and bad news

Good news: I connected all the wires for the iMac G5 LCD and inverter, and the 5V wire from the NUC front panel header, and it is alive!
DSC_7685.JPG

... With a leftover win7 installation that cannot boot anyway.

It probably just means I got the pinout right and I am a step ahead in the right direction.:headbang:

I did connect the native PSU's white wire to 12V via a 6.8kohm resistor rather than straight to 5V.

Now when the screen comes up as NUC boots, it went off and on twice before finally staying on. Is this normal?

Bad news: The iMac G4 LCD housing and bezel I ordered from ebay has been lost. :( Canada Post must have misdelivered on the day it said it delivered, because there was no delivery made at my home that day. I have opened a case with paypal.
 
Last edited:
Good news: I connected all the wires for the iMac G5 LCD and inverter, and the 5V wire from the NUC front panel header, and it is alive!
This is good news, well done. Can you post some pics of your work.
 
More Good news and bad news

Good news: The 20" back bezel and back panel FINALLY showed up today! I've closed the paypal case.

Finished the Mavericks installation and did a time machine backup. The NUC is back in its own case while I figure out the hardware mods.


Kind of expected: I put the Flowerpot together less NUC, reinstalled the neck, installed the back panel, LCD panel and bezel, less inverter, for a weight test. The 15" base is very prone to tip over when the panel is lowered more than half way. The G5 inverter really does not fit. The short length of the inverter cable on panel housing end limits where I can put the inverter, and either the housing's structural ribs or caps on inverter get in the way and I can't close the housing.

Bad news: Trying to determine if it is dual color, I might have fried the LED on the bezel by probing it with a multimeter. :banghead: Because one of the 3 screws securing the bezel of the back is right there, it'll be hard to slide in a pair of SMD LEDs, let alone 3mm ones. And the 5mm dual color LED I have is just not going to fit.

I hooked the LCD up the simplest way there is, and when the build goes on standby, it goes into a sorta burn in mode or something and cycles between R/G/B/white/black. Now I need to go find the way to off the monitor in this case.

Next: Need to get some very slender M3x12mm screws to bolt the panel together, and I may finally have to bite the bullet and get a G4 inverter. Now just need to find an ebay seller that will ship outside the "global shipping program".
 
More Good news and bad news, #2

The last few weeks have been spent on figuring out how to weigh the 15" dome down to support the 20" monitor, and that have utterly failed. Some quick search tells me I need to add 18lbs of weight, but the most I could find so far is 12lbs and that requires me to give up the optical drive, put my weights where the drive was, and make too many cuts in metal with anything from Dremel to 4.5" angle grinder to 6" and 14" chop saws. I am going to order the 20" faraday cage and see if they can get me the matching drive carrier.

For the LCD connection, I ordered the Dell Mini-HDMI -> DVI-I adapter straight from Dell, and built this:

img_20141102_212237.jpg


This is a male DVI-I plug that I got by breaking apart an extra DVI/VGA adapter. I then cut the leads from a DIP chip from 1972 (!) and soldered them on. Also soldered on is the 1kohm resistor for hot plug detect and wires for 5V and GND. The TMDS wires fit just like they would on a Molex jack's pins. When wires are assembled this thing will mate to the Dell adapter and secured against it, and the whole thing plugs into the NUC.

I now have the proper LCD inverter installed and hooked up. The monitor is now considered one piece. The bezel is hard to close, and a few attachment points in the lower right corner of the bezel have broken off, and teases me with the opportunity to pry out the white LED in there and put in a dual color one, except it won't come out! and I don't feel like prying it more than I have to, for I may likely have no way to reattach that bezel should it completely breaks off.

I have mostly figured out the solder points where I can bring connectors from the NUC to the iMac logic board. I have laid out the cut line of the motherboard but yet to actually make the cut. Then I am going to solder some wires to go up to the NUC. The ports complement are:

2 USB 2 ports retained
1 USB port removed. A USB3 extension wire will be secured here to provide the third accessible USB port.
Ethernet port retained.
2 1394 ports retained but no longer hooked up
:oops:
Apple pro speaker port removed, hole to be enlarged for a panel mount 4-conductor "phone headset jack" to go through.
Headphone port retained but no longer hooked up

Looks like I will need to get a backup picoPSU locally because ebay shipments from China is taking unreasonably long. While I figured out the imac hardware I moved the NUC to my room with a Samsung 19" monitor etc to continue to software setup. And I am not going well there too. :(

I am experiencing the "world fast forward" problem where everything is like 10x faster in the Mac install than it really is. This was supposedly an old issue long resolved, but I have no idea what of my software was out of date, and after doing the FakeSMC change steps I couldn't even boot properly. :( But I managed to download the 10.9.5 updater and installer again so I may have to reinstall 10.9.5 from scratch, probably following the new guide... AND this time using Clover because I like a full UEFI setup - I already converted my laptop to full UEFI booting.

Next:
Order 20" dome
Order another picoPSU, this time locally
Reinstall 10.9.5 on NUC
Cut up motherboard and hook up extension wires for ports

 
Sigh. I have just been informed from my source that their iMac G4 20" dome supply has run dry. I am now back to either adding 18 pounds of weight or wrap the dome with metal crutches. :(
 
Status
Not open for further replies.
Back
Top