iMac G3 mod - Video Connector

[DrJekyll_XYZ]

The Arduino Uno I ordered along with a linear actuator and a kettle lead socket all arrived today. I started looking into how to power the 12V linear actuator from the Arduino before I literally facepalmed at how stupid I was being. I want the actuator to turn on when the front button (push button) is pressed. The actuator works by being on or off. I don't need the Arduino at all, I just need to wire up the push button to a 12v circuit with the actuator. Talk about overthinking something! I think it should work fine for relaying pushing the power button to the Mac Mini itself, it'll just be a matter of positioning it right, which I can only do once I've moulded a mount for the Mac Mini. It should be able to translate things like holding the power button down to force power off etc. The LCD driver board uses a 12V supply so I can just slice into that too.
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That sounds so over engineered XD I can't wait to see that working too

 

[rockyhill]

The Arduino Uno I ordered along with a linear actuator and a kettle lead socket all arrived today. I started looking into how to power the 12V linear actuator from the Arduino before I literally facepalmed at how stupid I was being. I want the actuator to turn on when the front button (push button) is pressed. The actuator works by being on or off. I don't need the Arduino at all, I just need to wire up the push button to a 12v circuit with the actuator. Talk about overthinking something! I think it should work fine for relaying pushing the power button to the Mac Mini itself, it'll just be a matter of positioning it right, which I can only do once I've moulded a mount for the Mac Mini. It should be able to translate things like holding the power button down to force power off etc. The LCD driver board uses a 12V supply so I can just slice into that too.
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I can't wait to see it in action!

 

[Spanky Deluxe]

Although I've been super busy lately with work (healthcare which is a bit mental atm with coronaschenanigans), I did just manage to bodge together a frankendrive. I haven't tested it out in the iMac chassis itself yet but I'm hoping it will work fine in there as the slot lines up with the original.

Here is the SATA blu-ray drive sat above the original unaltered iMac DVD drive:



I then opened the iMac drive up and removed the guts. There are two tiny screws on the outside of the drive that you'll want to keep - the lid of the drive opens up like a car bonnet with them taken out (pull the edges at the front slightly to allow it to swing up). Everything inside, you can throw out. There is one raised bump near the front of the inside of the case that I needed to flatten. I used a hammer to bash it down but I'd advise against doing that and instead, just dremmeling it out in place. When you hammer it, it doesn't make it go flat, it just makes it go down so you end up with a bit of a bump on the underside. It should be fine for my purposes though anyway.

To keep the drive in place and at the right height, I used the same mouldable plastic as I used to mount the LCD screen - it's readily available on Amazon. You put the granules in boiling water, they go clear and stick together and then you can mould it to whatever you want. I smooshed it in and then put the drive on top. It's a bit ugly but it works and it means you can line things up with sight and feel rather than careful measurement of hard to reach areas.

Here are the insides of the drive after this:



It's just a standard blu-ray SATA slot loader drive. I got a cheap external USB case for optical drives (actually one meant for tray mounting as it was easier and cheaper to source) and I popped that open and removed the SATA->USB adapter. That's then plugged into the drive and routed out through the existing hole at the back of the iMac drive's case.

Once all close up, here's what it looks like:



I've tested it on another mac and it works fine:



I'm getting to the point now in my project where all that's left is basically to put together all that I've done before in a sturdy manner, solder some wires instead of using little jumper like cables, mount it all together and then clean the case up. It should all be relatively simple but it's finding the time that's the hard part! All of this other stuff I can jump in and spend 20 minutes on and make a bit of progress but now I need to spend a couple of hours wrapping it all up!

I'll keep you guys informed. I thought this drive bay approach might be of use to you guys working to keep the original iMac's screen though anyway as this all sits below it and might be useful if you want to connect an optical drive to your other hardware.

 

[rockyhill]

Although I've been super busy lately with work (healthcare which is a bit mental atm with coronaschenanigans), I did just manage to bodge together a frankendrive. I haven't tested it out in the iMac chassis itself yet but I'm hoping it will work fine in there as the slot lines up with the original.

Here is the SATA blu-ray drive sat above the original unaltered iMac DVD drive:

View attachment 899892

I then opened the iMac drive up and removed the guts. There are two tiny screws on the outside of the drive that you'll want to keep - the lid of the drive opens up like a car bonnet with them taken out (pull the edges at the front slightly to allow it to swing up). Everything inside, you can throw out. There is one raised bump near the front of the inside of the case that I needed to flatten. I used a hammer to bash it down but I'd advise against doing that and instead, just dremmeling it out in place. When you hammer it, it doesn't make it go flat, it just makes it go down so you end up with a bit of a bump on the underside. It should be fine for my purposes though anyway.

To keep the drive in place and at the right height, I used the same mouldable plastic as I used to mount the LCD screen - it's readily available on Amazon. You put the granules in boiling water, they go clear and stick together and then you can mould it to whatever you want. I smooshed it in and then put the drive on top. It's a bit ugly but it works and it means you can line things up with sight and feel rather than careful measurement of hard to reach areas.

Here are the insides of the drive after this:

View attachment 899891

It's just a standard blu-ray SATA slot loader drive. I got a cheap external USB case for optical drives (actually one meant for tray mounting as it was easier and cheaper to source) and I popped that open and removed the SATA->USB adapter. That's then plugged into the drive and routed out through the existing hole at the back of the iMac drive's case.

Once all close up, here's what it looks like:

View attachment 899890

I've tested it on another mac and it works fine:

View attachment 899889 View attachment 899888

I'm getting to the point now in my project where all that's left is basically to put together all that I've done before in a sturdy manner, solder some wires instead of using little jumper like cables, mount it all together and then clean the case up. It should all be relatively simple but it's finding the time that's the hard part! All of this other stuff I can jump in and spend 20 minutes on and make a bit of progress but now I need to spend a couple of hours wrapping it all up!

I'll keep you guys informed. I thought this drive bay approach might be of use to you guys working to keep the original iMac's screen though anyway as this all sits below it and might be useful if you want to connect an optical drive to your other hardware.

I was trying to figure out the best way to mount an optical drive but this is definitely something that hadn't occurred to me.
Great idea, when the time comes this is what i'll do.
Thanks!

Also, I've never heard of this mold-able plastic stuff. it seems fantastic.

 

[Spanky Deluxe]

I was trying to figure out the best way to mount an optical drive but this is definitely something that hadn't occurred to me.
Great idea, when the time comes this is what i'll do.
Thanks!

Also, I've never heard of this mold-able plastic stuff. it seems fantastic.

Here's the stuff I'm using: https://www.amazon.co.uk/gp/product/B01MZE4LYK

There do seem to be quite a few variants out there though. Once it's cooled, it's pretty darned solid. As long as it's not going to be in an environment that's going to be > 60 degrees celsius (140 degrees in Freedom units), it should stay that way. I've never had the inside of a computer case be anywhere near that so I think it'll be fine and it's only really malleable (kind of like fresh blu-tac) at >80 degrees (176 freedom).

 

[rockyhill]

Here's the stuff I'm using: https://www.amazon.co.uk/gp/product/B01MZE4LYK

There do seem to be quite a few variants out there though. Once it's cooled, it's pretty darned solid. As long as it's not going to be in an environment that's going to be > 60 degrees celsius (140 degrees in Freedom units), it should stay that way. I've never had the inside of a computer case be anywhere near that so I think it'll be fine and it's only really malleable (kind of like fresh blu-tac) at >80 degrees (176 freedom).

Great thanks for the link, I'm ordering some tonight. I sure hope it doesn't get hotter than 140 freedom units!

 

[DrJekyll_XYZ]

Although I've been super busy lately with work (healthcare which is a bit mental atm with coronaschenanigans), I did just manage to bodge together a frankendrive. I haven't tested it out in the iMac chassis itself yet but I'm hoping it will work fine in there as the slot lines up with the original.

Here is the SATA blu-ray drive sat above the original unaltered iMac DVD drive:

View attachment 899892

I then opened the iMac drive up and removed the guts. There are two tiny screws on the outside of the drive that you'll want to keep - the lid of the drive opens up like a car bonnet with them taken out (pull the edges at the front slightly to allow it to swing up). Everything inside, you can throw out. There is one raised bump near the front of the inside of the case that I needed to flatten. I used a hammer to bash it down but I'd advise against doing that and instead, just dremmeling it out in place. When you hammer it, it doesn't make it go flat, it just makes it go down so you end up with a bit of a bump on the underside. It should be fine for my purposes though anyway.

To keep the drive in place and at the right height, I used the same mouldable plastic as I used to mount the LCD screen - it's readily available on Amazon. You put the granules in boiling water, they go clear and stick together and then you can mould it to whatever you want. I smooshed it in and then put the drive on top. It's a bit ugly but it works and it means you can line things up with sight and feel rather than careful measurement of hard to reach areas.

Here are the insides of the drive after this:

View attachment 899891

It's just a standard blu-ray SATA slot loader drive. I got a cheap external USB case for optical drives (actually one meant for tray mounting as it was easier and cheaper to source) and I popped that open and removed the SATA->USB adapter. That's then plugged into the drive and routed out through the existing hole at the back of the iMac drive's case.

Once all close up, here's what it looks like:

View attachment 899890

I've tested it on another mac and it works fine:

View attachment 899889 View attachment 899888

I'm getting to the point now in my project where all that's left is basically to put together all that I've done before in a sturdy manner, solder some wires instead of using little jumper like cables, mount it all together and then clean the case up. It should all be relatively simple but it's finding the time that's the hard part! All of this other stuff I can jump in and spend 20 minutes on and make a bit of progress but now I need to spend a couple of hours wrapping it all up!

I'll keep you guys informed. I thought this drive bay approach might be of use to you guys working to keep the original iMac's screen though anyway as this all sits below it and might be useful if you want to connect an optical drive to your other hardware.

I'd just use an ultra ATA to sata and use the built in dvd drive myself. I hope you can squeeze it all in. Dying to see your power button solution

 

[rockyhill]

I got the boards today and I populated one .There are a couple of design flaws that I need to correct for the next
revision.

1 - I wired the power button someplace I din't want on the atmega but I fixed that in the code but I want to use the
input I intended so I have to change that.
2 - The power connector on the terminal strip is directly above one of the mounting posts so I need to move that.
3 - the VGA connector is in an extremely inconvenient location so I have to move that.


All that aside, it actually worked!

Here are some pics. I'll post a video later.

 

[DrJekyll_XYZ]

I got the boards today and I populated one .There are a couple of design flaws that I need to correct for the next
revision.

1 - I wired the power button someplace I din't want on the atmega but I fixed that in the code but I want to use the
input I intended so I have to change that.
2 - The power connector on the terminal strip is directly above one of the mounting posts so I need to move that.
3 - the VGA connector is in an extremely inconvenient location so I have to move that.


All that aside, it actually worked!

Here are some pics. I'll post a video later.

View attachment 899973 View attachment 899974 View attachment 899975 View attachment 899976 View attachment 899977

Hey that looks great, I see what you mean about the VGA position but to me that looks awesome. Fantastic job

 

[rockyhill]

Here is a link to the video

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Hey that looks great, I see what you mean about the VGA position but to me that looks awesome. Fantastic job

Thanks!

Yeah , I'll have to move things around but this board is a good starting point. It even sends the EDID info.

 

[pucher]

I hope your CRT isn't broken. Good luck

Update on this, quarantine has finally given me the time to hook the CRT back up with the original logic board. Everything seems to be in order, but my setup still is not working. Seems that a lot of progress has been made on this project here, so I think I'll probably just order a board once it's refined before trying to cobble something together with my mess of jumper wire again, haha. Thank you for all your work, rockyhill.

 

[rockyhill]

Update on this, quarantine has finally given me the time to hook the CRT back up with the original logic board. Everything seems to be in order, but my setup still is not working. Seems that a lot of progress has been made on this project here, so I think I'll probably just order a board once it's refined before trying to cobble something together with my mess of jumper wire again, haha. Thank you for all your work, rockyhill.

I was in Tenerife a couple of weeks ago seeting up some equipment on the RRS James Cook, a British vessel, during a corona virus
"outbreak". I got back to the U.S. and began my precautionary self-quarantine and began to tele-work. I now have an extra
1.5 to 2 hours a day because I have no commute so I've been able to play a little with this project.

COVID-19 is terrible but at least it has given us a little extra time to do stuff so I'm glad to hear you were able to use your
time to confirm that your CRT isn't broken!

Are you still planning to use a raspberry pi for your setup? If you are, I just finished a very good test with one.
I wired up the down-converter board and used it to power a raspberry pi and an audio amplifier. I played some movies
over several hours and left the pi and CRT running all night without issue.

One of the voltages the down-converter board provides is 5 volts but unfortunately the raspberry pi needs around 5.5 volts
to run properly and not give the under-voltage warning. I purchased a DC to DC converter and used one of the 12 volt outputs
from the down-converter board to power the raspberry pi and the audio amp. Next I'm planning on powering a USB hub
with it.

I like the idea of using the down-converter board because I already own it, it powers on and off along together with the CRT
and obviously, it fits nicely.

If it ever dies however I'm sure I can find a power supply that will take the 24 VAC and produce usable DC outputs
at a high enough current to power all these things.

The other reason I want to use the down-converter board is that I don't need to deal with mains power.

 

[Spanky Deluxe]

The power button works!

I haven’t connected it to the main switch yet because here it is working with a test switch on a breadboard. Next comes wiring it in to the main one and splicing power out of the LCD driver to power it, so a bit of soldering. You can see me power the Mac mini on with it and then force power it off (hold down for a few seconds).

More work ongoing but I figured you guys might get a kick out of this crazy switch solution!

 

[Spanky Deluxe]

Update: Made good progress this weekend. I moved it all down to the dining room table so that I could do some stuff close to my wife while she watched tv. Has the added benefit that she wants it all gone ASAP which puts pressure on me to get on with things!!

The front switch is now wired up and it works! The speakers work (although the foam fell apart from one of them yesterday after looking fine for ages so I’ve had to order some replacements from China), the microphone work (albeit it’s a bit crap), the slot load Blu-ray works in place and everything can be powered from a standard kettle lead socket at the back.

Now I just need to modify the side panel to fit everything I want on there and mount all the cables for that and then to clean up the chassis itself.

The hardest thing is going to be working out how to put it all together again as I have a bowl of screws which I’ve completely forgotten where they came from!

Insides atm:

 

[anotherelise]

@rockyhill Did you ever get the EDID for the slot loading iMac g3?

I'm using this edid code https://github.com/qbancoffee/edid_simulator

After getting everything working connected to my MacBook Pro over a usb-c to vga connect the color/brightness on the iMac's monitor is way off . I then realized the edid in that GitHub repo is for the emac display, which makes me think having the right EDID for the iMac display will fix the brightness/color issue.

I mixed your init and edid code into one Arduino sketch to make it work with a single ardunio. The Arduino controls a switch to change between slc/sda being connected to the monitor for init or the computer for edid.


Doing this mod has become my shelter in place project

 

[rockyhill]

Update: Made good progress this weekend. I moved it all down to the dining room table so that I could do some stuff close to my wife while she watched tv. Has the added benefit that she wants it all gone ASAP which puts pressure on me to get on with things!!

The front switch is now wired up and it works! The speakers work (although the foam fell apart from one of them yesterday after looking fine for ages so I’ve had to order some replacements from China), the microphone work (albeit it’s a bit crap), the slot load Blu-ray works in place and everything can be powered from a standard kettle lead socket at the back.

Now I just need to modify the side panel to fit everything I want on there and mount all the cables for that and then to clean up the chassis itself.

The hardest thing is going to be working out how to put it all together again as I have a bowl of screws which I’ve completely forgotten where they came from!

Insides atm: View attachment 900525

Yes, the wife factor, this has helped me finish many dining room table projects in timely fashion.

So you've forgotten where the screws go huh? Same thing happened to me so when I disassembled
my second slot loader I bagged and labeled the screws. Here are some pics, maybe they can help you at lease
eliminate the ones you don't need.


I just realized I should photographed a ruler for scale.......


Your mod is looking great by the way!

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Just Finished and ordered the breakout board for the down-converter board. This should help power everything I need to power.

 

[Spanky Deluxe]

Thanks for the screw bag shots, rockyhill, that'll be a big help!!

 

[rockyhill]

Received the J22 board today and it works!
Just need one more board......

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Here is a video of the board in action.

 

[Spanky Deluxe]

That looks great! Such a clean setup, you're doing a great job!

 

[Spanky Deluxe]

Managed to spend a few minutes making a bit more progress today; hooking up the cables to the side panel:



I replaced the FW400 connectors with USB ones, so had to carefully dremel out a little bit. It’s a bit messy because there’s not much room to work with. I also drilled out the microphone and headphone holes a little so that the 3.5mm extensions could fit in nicely. I cut most of the rubber back on the connectors so that they sit flush and I used a whole lot of hot glue to hold it all together. The phone connector’s been replaced with a MDP connector instead.

 

[rockyhill]

Managed to spend a few minutes making a bit more progress today; hooking up the cables to the side panel:

View attachment 900971
View attachment 900972
I replaced the FW400 connectors with USB ones, so had to carefully dremel out a little bit. It’s a bit messy because there’s not much room to work with. I also drilled out the microphone and headphone holes a little so that the 3.5mm extensions could fit in nicely. I cut most of the rubber back on the connectors so that they sit flush and I used a whole lot of hot glue to hold it all together. The phone connector’s been replaced with a MDP connector instead.

That's looking nice! what did you end up doing with the two buttons?

 

[Spanky Deluxe]

That's looking nice! what did you end up doing with the two buttons?

They're wired into the LCD controller board. I *think* one of the buttons changes input but I've not actually connected multiple devices to the display at once yet so I haven't tried it out; I figured when/if I get round to adding a video in port, I'll play around with the buttons and see what works best. It's easy to switch them to other buttons for the LCD controller board

 

[crozone]

Are you saying install Linux automatically then when it's done use the OS 9 disk to repair the driver partition with the apple drivers and that makes it work?

Yep, use a partition manager to create an empty space for Linux to install to (or just set up the partition table like that to begin with), then do the automated (L)ubuntu install. Linux should then appear in the option key boot menu.

Then fix the OS9 install by booting up the OS9 installer, running disk utility, and "updating disk drivers" from the menu strip. This fixes OS9, because classic macOS on PowerPC is an interesting and elegant hack on top of the previous Motorola 68K versions, and it needs to pull disk drivers from magic partitions for reasons.

I might also have a go at getting the EDID since I have Lubuntu installed already (also macOS9 and macOSX if they help) but I doubt I'll have much more luck. Is it possible these machines don't actually have a traditional EDID?
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Really nice to see the progress going on in here lately. I'm performing an iMac mod at the moment myself - something I've been planning to do for about ten years since I picked up a gorgeous Ruby iMac at a car boot sale. I've decided to get rid of the CRT for my one although I'm planning on making use of the existing speakers and mic if possible so the info in here will still be invaluable. My project should be much simpler, in theory as it's just using the iMac G3 as a case really and there's *loads* of room for something like that.

I took a nice step forward today with fitting the LCD. It's a test fit for now but I think it'll likely be ok as it is. Photo of it in place attached. Nothing is screwed and all the plastic is just resting there and there's lots more to do.

Whoa nice, I'm currently doing the same thing (but trying to cram in a gaming PC). May I ask what LCD panel you're using? It looks quite nice. I'm using a HYDIS HV150UX2 mounted like this:

The resolution is great but the response time and colours leave a little to be desired, but maybe that's just the reality of old 4:3 screens at this stage, even if they were designed for ThinkPads.

First things first will be to get this all put together. I don't have a huge amount of time to spend on this project so I'm prioritising 'getting it done well enough' over 'getting it done perfectly'!

I feel this... mine has been sitting there for about 6 months while I procrastinate doing CAD for more of the parts.

 

[rockyhill]

Update: Made good progress this weekend. I moved it all down to the dining room table so that I could do some stuff close to my wife while she watched tv. Has the added benefit that she wants it all gone ASAP which puts pressure on me to get on with things!!

The front switch is now wired up and it works! The speakers work (although the foam fell apart from one of them yesterday after looking fine for ages so I’ve had to order some replacements from China), the microphone work (albeit it’s a bit crap), the slot load Blu-ray works in place and everything can be powered from a standard kettle lead socket at the back.

Now I just need to modify the side panel to fit everything I want on there and mount all the cables for that and then to clean up the chassis itself.

The hardest thing is going to be working out how to put it all together again as I have a bowl of screws which I’ve completely forgotten where they came from!

Insides atm: View attachment 900525

So just got around to testing the mic and I found that I had made a wiring mistake in the schematic so I'll have to fix that
but after I wired it correctly , I found that the mic is like you said "it's a bit crap". After playing with it for a while
I think the problem is that it needs a pre-amp before going into the mic input of a computer. I'm going to try
to make a small 1st stage transistor amplifier to see if it helps. If it does I'll add it to rev 2 of the circuit.
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Yep, use a partition manager to create an empty space for Linux to install to (or just set up the partition table like that to begin with), then do the automated (L)ubuntu install. Linux should then appear in the option key boot menu.

Then fix the OS9 install by booting up the OS9 installer, running disk utility, and "updating disk drivers" from the menu strip. This fixes OS9, because classic macOS on PowerPC is an interesting and elegant hack on top of the previous Motorola 68K versions, and it needs to pull disk drivers from magic partitions for reasons.

I might also have a go at getting the EDID since I have Lubuntu installed already (also macOS9 and macOSX if they help) but I doubt I'll have much more luck. Is it possible these machines don't actually have a traditional EDID?
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Whoa nice, I'm currently doing the same thing (but trying to cram in a gaming PC). May I ask what LCD panel you're using? It looks quite nice. I'm using a HYDIS HV150UX2 mounted like this:

The resolution is great but the response time and colours leave a little to be desired, but maybe that's just the reality of old 4:3 screens at this stage, even if they were designed for ThinkPads.



I feel this... mine has been sitting there for about 6 months while I procrastinate doing CAD for more of the parts.

I think you're right and it probably doesn't have an EDID in the traditional sense. However, I was able to construct an edid
that works with all three supported resolutions. I added this to the second atmega chip on the J20 board it works well enough.

I've hooked into several computers with a VGA connector and it sends the edid and the computer automatically
configures itself to the correct resolution and refresh rate.

I'll put it up on the repo.

 

[Spanky Deluxe]

So just got around to testing the mic and I found that I had made a wiring mistake in the schematic so I'll have to fix that
but after I wired it correctly , I found that the mic is like you said "it's a bit crap". After playing with it for a while
I think the problem is that it needs a pre-amp before going into the mic input of a computer. I'm going to try
to make a small 1st stage transistor amplifier to see if it helps. If it does I'll add it to rev 2 of the circuit.

Yeah, the mic works but when I'm talking it's very very quiet but tapping on it sends a max signal (clipped), so my guess is that the mic is just really bad. I'll test it a bit more when it's all put together but I'm not too worried about it as if I were to ever use this computer for any real communication, I'd likely get a USB we cam, connect my Airpods or use a 3.5mm connected mic.

Whoa nice, I'm currently doing the same thing (but trying to cram in a gaming PC). May I ask what LCD panel you're using? It looks quite nice. I'm using a HYDIS HV150UX2 mounted like this:

The resolution is great but the response time and colours leave a little to be desired, but maybe that's just the reality of old 4:3 screens at this stage, even if they were designed for ThinkPads.

I feel this... mine has been sitting there for about 6 months while I procrastinate doing CAD for more of the parts.

Yours is mounted so much neater than mine - I went for the quick route of squidging in this mouldable plastic stuff. It's not perfect but it meant that I could get the screen mounted after about 15-20 minutes of work. My screen's a Sharp LQ150U1LW03 so similar to yours. I know what you mean about the colours - there's a bit of what looks like dithering at times on mine but it's not noticeable most of the time. I suspect they took a few shortcuts for colour representation in these older panels. Still, there aren't many choices for 15" displays. I think there's one panel that's higher than 1600x1200 res 'out there' but I couldn't actually find any available anywhere and I got this one for dirt cheap. The controller cost way more!

Are you using CAD to create models to 3D print? Is that how you did your panel mounts? It looks so much more professional than mine. Alas, I don't have a 3D printer and if I had waited until I got one, the old iMac would likely have sat in the cellar for another 10 years untouched. The only way I could get this done is by bodging it and hoping for the best.