Fitting an iTuner PW-200-M ATX PSU inside A1200

[Painkiller]

This tutorial is still a work in process and will be updated from time to time whenever I have the time to work on my new investment

So everything you do you do at your own risk!

If I have posted misinformation then please correct me and I will edit the tutorial.

So here is a little background. I started this project because I wanted my A1200 to remain in its original case with minimum modificatioins and the PSU needed to have the juice to power up BlizzardPPC 200Mhz 060@50Mhz and bVision. I also didn't want to use a big normal sized ATX PSU outside the case, because the additional power connectors would be just too ugly on my desktop

What you need:
There is a little PSU called iTuner PW-200-M  can be found from http://www.mini-box.com/PW-200M-DC-DC-power-supply?sc=8&category=13

You will also need a good 12VDC power adapter for that, also found from http://www.mini-box.com/110w-12v-8-5A-AC-DC-Power-Adapter?sc=8&category=13

That 12VDC power adapter has a total ouput of 110W which should be enough for the configuration I mentioned above. PW-200-M can manage a 6A constant load on 5VDC line and peak at 10A which should also be enough.

Here is what you need to do to fit the PSU under the floppydrive. Desolder the ATX connector from the PW-200-M PSU. I would also reconmed to desolder the original Amiga PSU connector, so that you can run thick enough wires directly to the PCB.

Here is a picture of the connection on the Amiga PSU connector end after desoldering and running the wires directly to PCB. I used 1mm² wire for the O VDC(COM) line, and 0.75mm² wire for 5 VDC line. The thicknes for the 12VDC line and -12VDC line aren't so important so I used a 0.5mm² wire for those.



Sorry I'm unable to upload the picture for the ATX PSU end now. Anyways here is a pinout for ATX 20pin connector. I'll upload the pic ASAP

EDIT: How stupid of me I forgot that one can upload pics to here So here it is and more pictures coming



http://www.hardwarebook.info/ATX_Power_Supply

[Painkiller]

Here are rest of the pics from the installation:



I had to cut a little plastic to make it go lower so that the floppy drive would fit over it. But nothing that would show outside the case.



Added some cartong to insulate the floppy from the PSU as it made a little contact to capasitor shielding on the PSU.



Here it is in place. I used hotglue to secure it.



And here is how it looks like from the backpanel.

With this modification I was able power up my BPPC and BVision + I got the power switch right in the back of my A1200

[Painkiller]

@adonay

The ATX PSU barely heats up (if at all). Most of the heat will be generated by the 12VDC PSU outside the case.

[Painkiller]

I'd say that trickiest part would be cooling down the BPPC card, but I have seen some great solutions in the photo gallery. I personally had a flat fan in the bottom, but for that I had to lift up my amiga and I didn't like that. Now that I'm selling my BPPC and BVision away I'm just happy to have 12VDC solution in my amiga + no fans (I just hate'em, even my PC doesn't have any fans).

[Painkiller]

How was the powerswitch fitted? It doesn't seem like it's a part of the PSU that you bought?

I bought the power switch from local electric shop. Just make sure that it isn't an push button that releases contact after pressing othervise it wont power up. To have the PSU powered up you need a constant connection between the wake up and ground after you break the connection ATX psu will power down.

[Painkiller]

After all this, you are parting with the magic parts???
With this wonderful mod, I'd think it would be time to BUY a BPPC and BVision for it and go OS 4

I still have a BPPC, but I decided to go with tower case and G-REX PCI which I haven't been able to get working... I just don't have the time and will power at the moment to streach my nerves with Amiga... I really hate the software problems and lack of good documentation or a simple tutorial from start to finish how to get your PPC working etc. I was in plans on doing one, but my plans has been pushed to distant future and might be that I will never try it as I still have my Peg II and seems like MOS 2.0 is hopefully around the corner.

[Painkiller]

Hello.

I've made the hack but I have one problem.
12v never stops to supply power!! (when the on jumper its out too)
5v works normal. On when its on and off when its off.

Any idea?

What jumer are you talking about?

Have you tired other 12V connections from the ATX PSU side, there are plenty of 12V outlets.

[Painkiller]

looking at the photo you do not need keyrah,you can still attach the standard A1200 keyboard.

one thing does concern me is heat under the floppy drive. pico PSU are silent PSU'S but here under testing i found the pico 120w needs cooling under *extreme loads* otherwise voltage will stray.

but this is a 200w PSU so under extreme loads keep a eye on temperture as this is under the floppy drive.

it's still a excellent project.

In my sterstest I found ou that it did not heat up much don´t remember exact readings but it was below 50 celsius. The PSU it self is quite efficient so most of the heat comes from the power brick attached to it.

[Painkiller]

im talking under **extreme** loads.

here is my deaktop config:

PICO 120W
A1200 desktop PPC 268Mhz with Bvision,128Mb ram,
indivision ( runs on seperate 3.3v from PSU )
elbox eide mkIII.

Well PICO 120W shouldn't even be able to handle MAX currents that your system draws from 5VDC.

[Painkiller]

Oh yeah, I remebered that PicoPSU 120 had 5VDC rating at 4A, but now reading at the manual it says 5VDC max load 6A  peak load 8A where as the PW200M has the same max load of 6A, but peak load is at 10A. So not much difference in there.

[Painkiller]

Yes, I tryed all the 12v points.
Jumper: well, the power on

Please dont tell me that you are connecting a jumper to the pins sticking out of the PCB at 90 degrees? If so that my friend is a 5VDC outlet and you are short circuiting it to the ground! PS On Switch on my picture means that red switch that I have drawn.

[Painkiller]

It really sounds like your system is drawing too much power from the PSU which is odd. What type of 12VDC PSU do you use to power PW200M?