Antonis' Imac G4 17 build. Ongoing and in need of some help.

Antonis' Transmac G4 17''.

UPDATE no.4: The iMac is 95% ready. Build pictures will follow!

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UPDATE no.3: I report the screen is working as it should and it is perfect!!! The cables on this Euro model were a little bit different than the one shown at various illustrations.
I m calling my build the Transmac, in other words, the 1Ghz Imac that wanted to be an 800 instead. I wired the screen with the 800mhz instructions and.... voila. Pictures further down this page.

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UPDATE: Video on the opening post with the problem that seems to come from the 3.3v connection of the grey wires.

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Dear friends,

Inspired from Nucimac G4, Dremeljunkie's info and MacTester's build, I decided to move on with my own G4 17''. Since I am in Europe I really wanted to have a 220V model. Fact is that a decent working one, cost me around $360 (around 285 Euros). I proceeded with my build as per the instructions of Ersterhernd's Nuci and Dremeljunkie. I have connected everything up and I have the following problem.
1) I should tell you that the computer was working fine as a normal G4. Lights, screen, audio everything.
2) When I tried to test the inverter on its own with the pico psu, I had the flashing backlight issue where I read that it could be a problem from the crocodile plugs for the ground connections.
3) I hard wired everything so as to be sure that the connections were ok.
4) I turned on my pico psu grounding pin 14-15. I tested all connections that they were giving the correct voltages.
5) I unplugged it and I connected all cables to it with snuggly fitting pin connectors.
6) When I turned it back on the pico's red led flashed quickly while making a very fast relay switching noise. After 3 seconds the led turned off. I reapeated this process 2 or 3 times and it still did the same thing.

Does anyone know what this means?

Thank you guys in advance.

Antonis

https://www.youtube.com/watch?v=FY8QmBabnzE&feature=youtu.be

UPDATE: Blinking led issue resolved. I was using a 12v psu with low amperage just for testing.
I plugged in the nuc psu and the leds lighted up constantly for 3 seconds but again they went off.
Any input would be very much appreciated.
I am attaching my pico pinout and my 3... well 4 way splice.


Edit: The pink wire from the grey cable is detached from the v on the left of the picture for illustration purposes.

Pico's have built-in overvoltage protection. I had this issue with my 20" iMac G5 build. I would suggest testing each rail (3.3V 5V and 12V) separately to see if you can isolate the cause. The picopsu is fussy, and are very easy to damage, as I have found out the hard way.

Good Luck and lets see some more photos...


Cheers!

Could it be that the power from the 65w nuc brick isn't enough??
I will check the pico with just a led circuit on when I get home again to see if it works ok.
I ve read so many bad things about the pico, that i fear it is the weakest link in this build.

aaantonis said:

I ve read so many bad things about the pico, that i fear it is the weakest link in this build.

Click to expand...

You are absolutely correct. The 65W PSU should be plenty for a 17" G4 build, I verified that with my Kill-A-Watt meter.

ersterhernd said:

You are absolutely correct. The 65W PSU should be plenty for a 17" G4 build, I verified that with my Kill-A-Watt meter.

Click to expand...

I read that you did it thay way, and thats why i didnt bother buying a 90w extra brick.

Updated opening post with video of the problem.

The Transmac finally has a working screen!!!!
I 'm not sure if you can see the black and white cables on pins 6 and 7. It is the 800mhz pinout from dremeljunkie's tutorial.

I want to be honest and tell you that this inverter is very forgiving.... Out of despair at some point, I wanted to try something and I didn't even notice that I was holding the pico the wrong way... Well, I send 5V to the 12V and... 12V to the 5 volt red inverter cable.... ouch! It is still alive...

P.S. I am absolutely sure that mine was a 1Ghz model since it was a working unit but I also doublechecked the printing on the G4 chip itself.

Keep the good work going.

Although I am pretty sure all iMacs are 100-240V, works equally well anywhere in the world, and all you need is to find the right power cord.

The iMac is almost ready.

Work still to be done:

Waiting for USB 3.0 short extension cables and for 802.11ac/Bluetooth 4.0 pcie card to arrive
Build pictures will be posted when everything is set and ready
Make a carbon copy of the drive to an external hdd before executing the last step on fakesmc (From WonkieDonkey's tutorial for the 4250. First time I tried it, it messed up my perfectly working installation.
I have inserted a usb cable and an ethernet cable through the modem hole at the back to test ride my baby.

I want Ester's, MacTester's and whoever has ever built a G4 opinion, on the only thing that didn't go according to plan.
The red inverter cable had to be connected to 5V instead of 3.3, otherwise I had no backlight. I could faintly see the nuc boot up logo. What do you think went wrong?