Slimline PicoPSU Power Mod

[sirnephilim]

Fairly simple variation on a common power mod. Take a PicoPSU and remove the ATX connector and all unnecessary other connectors from the board. Solder in your 5 wires, add a 12V power supply of sufficient wattage and golden.

https://imgur.com/gallery/hQFIaDF


Step 1: Cut ATX connector from PicoPSU. I used flush cutters to remove the bulk of it then used a soldering iron to remove the pin remnants and most of the huge solder blobs left on the board.


Step 2: Remove unnecessary connectors. In my case there was a size discrepancy between the existing 12V input plug and my supply so I replaced that. For the white SATA/misc connectors I pulled off the plastic with pliers (they're only held on by tension) then used the soldering iron to remove each pin individually. Could also have used a desoldering tool to remove the entire assembly but this ends up being easier.


Step 3: Solder on your 5 wires. I followed the color code used in the ATX wiring standard (Red for +5V, Yellow for +12V, Blue for -12V, Black for the 2 ground wires) to make things easier. Again, in my case I also had to desolder the existing 12V input and replace it with my own barrel plug. For the sake of streamlining I biased the ATX wires toward the opposite end of the PicoPSU than the 12V input so the end result would have a smaller profile. (In plain English, flatten the wires against the board and solder them flat so they don't stick out, and aim them away from the 12V input side.)


Step 4: Add heatshrink. If you don't do it now you won't be able to later.


Step 5: Assemble 5-pin Amiga power connector. I got mine on eBay for about $10 shipped, YMMV. Make sure to slide on the black plastic casing first - voice of experience. For first timers, heavily pre-tin your wires then insert them into the correct holes on the 5-pin connector, then apply heat from your soldering iron to the small amount of tinned wire still protruding from the top. Clean results every time with no accidental bridging.


Step 6: Insulate. I didn't have heat shrink large enough to enclose the PicoPSU, even stripped down. So I used silicone tape instead, which is basically electrical tape's steroid using older brother - it's not coming off without cutting. (I bought some to repair my desoldering gun's tubing and now find so many uses for it.) After a full night of running my Amiga 600 with 40MHz Furia it was about 90 degrees, so heat is not an issue.


Sorry I don't have any assembly pics, I'd already stripped the PSU so it would have been nothing more than soldering some wires and wrapping it in tape. If I repeat the mod I'll be more diligent.


An easy alternative to this mod if you have a 500 or 1200 would be to make it an internal PSU mod. The ones I've seen are just massively oversized with the unnecessary adapter board and trying to accommodate the ATX connector.