Cezar's iMac G5 20 inch project

[cezar.lamann]

Introduction:
Hi all. After several months looking through Ersterhernd's, Kiwi's and Dremel junkie's projects, I decided to roll up my sleeves and try my own iMac build. There are several reasons on why I'm trying to do this:

• I always wanted to have an All-In-One PC, built by me.
• I like older iMacs look-and-feel.
• I think it will be a nice project to de-stress.
• All-in-ones are expensive in Brazil, even the weakest ones (those with Celeron/Pentium procs). Specifically, Apple practices sky-high prices here. According to my calculations, I need to work almost five months to buy a Mid 2016 21.5 inch Core i5 2.8ghz iMac.

So, I bought a reasonably good-looking condition iMac G5/2.0 20-Inch (ALS) (A1076/EMC 2056) at local "ebay-like" e-commerce (Mercado Livre), for BRL 300.00 (US$ 80, direct conversion).

Note 1: I don't know what those gray smudges could be.
Note 2: Light conditions were not ideal when I took those pictures, five months ago. I'm sorry for that.

The seller advertised it with an intermittent defect: It remains working only almost a minute after booting, then suddenly it turns off. Sometimes it works for an hour or two. Sometimes it couldn't even start. I was thinking that it could be some bulging caps.

When it arrived and I opened it, the caps were not bulging at all. All of them were already replaced. There was some coil whining noise, so I stated that the PSU was somewhat dying. There was no Ambient Light Sensor anymore. I think that the PSU were previously replaced with a non-ALS iMac PSU

This specimen uses an IdTech display, which is somewhat different from LM201W03 found on several tutorials out there (Dremel Junkie), albeit using the same connector and inverter cables/box found on Ersterhernd's G5.

I have some plans to this one, based on Ersterhernd's iSight G5 steps (use an aftermarket PSU with an 12-24v upconverter):

• The first, cheaper and faster idea, is to put a NUC inside.

or

• Squeeze the most hardware I can, removing bottom cooling fans, cutting the backplate and bottom frame, fitting an inverted, upside-down mini-ITX board, with a IPC FlexATX 1U PSU.

iMac's default PSU measures 187mm (L) 80mm (W) 44mm (H). FSP400-60FGGBA measures 150mm (L) × 81.5 mm (W) × 40.5mm (H). I'm daring. It's a crazy idea, but I think it could fit.

More notes:
Since I'll do everything in my spare time and somewhat tight budget, this project will run on "baby-steps".
Since english is not my primary language, please forgive some grammar mistakes and misspellings.

Cezar

 

[xgekox]

Hi, for me you can use a mini-itx, this is my "work in progress".For example this is the first photo of mine 17"model

 

[xgekox]

This...

 

[cezar.lamann]

Hi, for me you can use a micro atx, this is my "work in progress".For example this is the first photo of mine 17"model

Thank you @xgekox for sharing your progress. It's good to see that I'm not alone in my "craziness" of doing an iMac with spare GPU.

After some brief analysis of your picture, I saw you're using a spare controller/inverter board set, to drive your LCD. Could you share your experience using this kind set of boards?

 

[xgekox]

Hi my project isn't fineshed but I share whit you my progress. I've tryed to search any document about the on board lvds connector, but I haven't found nothing on internet and for that I've used a this controller board (purchased on EBay). On this card there is a hdmi with audio, a audio controller and with this I can use a full hd LCD. For the panel's data sheet I've seen on this site http://www.panelook.com/ and after I've buyed a used Lcd on the Bay.
At the Beginning I've used a motherboard Gygabyte b75tn with intel original thin heatsink and cpu Pentium G2100T (3M Cache, 2.60 GHz), but after a nsulation error of the lower part is broken
After I purchased a intel dq77kb.
For the power supply I want to use 2 external power brick (1 for the controllerboard and 1 for the moterboard).
For the motherboard screws I purchased a model in plastic material on ebay because It's more simple cut and adjust the length.
For to eject the hot air,I thought I'd use one of the original modified plastics for use as a conveyor towards the hole originally used for the power supply cable (suitably enlarged).
For the fan, I initially thought of using the black original sink but then I realized I needed an additional centimeter of space to close the body, for what I will have to try to convert the original fan in PWM.

 

[xgekox]

Initially I wanted to use a passive additional video card, but then I had to abandon the idea because the motherboard only supports 40w on pci-e 4x and this caused freeze.

You'll spot another old photos, when I have time, and I will go on, you will post the latest. Sorry for my terrible English

 

[ersterhernd]

Always great to see a new iMac build launched. Good luck with your project. My A1076 is coming up on 2 years old now. It still gets daily use and never skips a beat. Sierra is next, I'm hesitating because El Cap is working so well.

Cheers,
Ersterhernd