Discussion New to "Pico" style PSUs. Need some help

Mansen

Efficiency Noob
Original poster
Oct 13, 2020
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Hey Y'all.

I'm working on a project with a gutted Macintosh Classic. There's enough room for an ITX board, so I was thinking I'd toss a 3400G based system inside and power it with one of those slim PSUs - because there isn't really room for an SFX PSU inside or any need for it, since I'll be running it with just the iGPU, 2x8GB RAM and an NVME for emulation.

That's as far as I've come though - I have zero experience with these tiny form factor PSUs, SFX in a Sentry 2.0 case is the smallest I've ever done. I've looked at the Pico 160-XT as well as HDPlex as possible solutions. Since I won't be using any kind of GPU or HDD, I figured it might be possible to adapt the Molex output of either of these to work with the LCD adaptor board (shown in the gallery below) which requires 12V 4A to drive it using a DC plug.


Quick overview of the project and size allowances.
 

Choidebu

"Banned"
Aug 16, 2017
1,196
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I've made molex to dc barrell jack before for hdplex 160w plugin board. It plugs to 4 pin pcie output from the board to lcd driver board's dc jack input.

Works fine, added bonus is your lcd turns on and off with the pc, just like a laptop.
 

smitty2k1

King of Cable Management
Dec 3, 2016
967
492
HDPlex is 19v BTW.

GUnqiue and J-Hack also make 12v plugin boards. J-Hack is very active (and Gury is also somewhat active) here so you could reach out to them.
 
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Mansen

Efficiency Noob
Original poster
Oct 13, 2020
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Yikes - Yeah this is why I asked before buying anything. That would have been a ... fun magical smoke moment I'm sure. ?
 

Choidebu

"Banned"
Aug 16, 2017
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We're talking outputs here, right? Then pcie OUT outputs 12V.

The hdplex takes 19v input.

I did it. See my build in the sig.
 

Choidebu

"Banned"
Aug 16, 2017
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The question of hdplex or j-hack or other pico, is what ac-dc brick you have or plan on using. It's either 12V or 19V.

The pico unit will then outputs one or more:
1.ATX 24 pin
2.EPS/cpu -> 12V
3.PCIE/gpu -> 12V
4.sata -> sometimes 12V, sometimes 12V+5V

So you can bet whichever you choose WILL output 12V.
 

Mansen

Efficiency Noob
Original poster
Oct 13, 2020
7
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I guess that mostly depends on the wattage needs. Doing a bit of google people seem to agree that something like the 3400G tops out at around 120W with both CPU and iGPU at full load. So something in the 160-200W seems optimal.

As for the brick. I could probably fit it inside of the bottom of the case if it's your typical laptop sized brick, and then do a proper AC power socket and power button to match and mount like the Mac used to have on its built in PSU-board out the back.
 

Choidebu

"Banned"
Aug 16, 2017
1,196
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This is the latest state of this build:



(I've since used proper M6 bolts to mount the monitor arm, moved it to the left a bit and the monitor to the rightmost so it's more centered, which also made room for my internal USB3 SD card reader mod in the third skyslot from the right)

That's an 11.6" ex-netbook monitor, gutted and remounted to its original case, with display interface board mounted to its back like so:



The display board is connected via (20cm cable) hdmi, and it is powered by a custom 12V pcie to barrel jack connector I made, coming out from the dynamo mini through a skyslot beneath the arm mount. So it powers up and down with the pc.

The monitor arm is just a regular two joints 20x20 vesa mount, two arms ended up being too heavy and bulky that I removed one of them. Originally I planned on using the hinge assembly of the donor netbook, but couldn't quite figure out how to reliably secure them without scratching my case so...

This has been our daily driver (my wife uses it more, really) for over a year already. My only gripes with it are:
  • RX550 is only slightly better than 2400G. Could've dropped power requirement from 180W max to 120W max, 120W avg to 85W avg. Unfortunately...
  • Asus B350-i is great, but no display output meaning I'm stuck with dGPU.
  • I got an internal USB2 x2 connected to the header directly and two wireless dongles plugged to it, but a metal case means now my wireless keyboard and mouse cannot be operated reliably over 2 meter from the pc.
Things to do next, in order of priority:
  • Display interface board's enclosure is currently needlessly hits the arm making it cannot flush when folded.
  • Implement manual brightness control with rotary thumbwheel, maybe somewhere on the bottom of the display.
  • Open up my m.2 wifi card and try connecting the antenna input to use the ones built into the monitor case.... see and compare how it works.
Spec:
AMD Ryzen 5 1600
Noctua NH-L9a (with AM4 bracket)
Asus ROG STRIX B350-I
Team Vulcan 16GB (2 x 8GB) DDR4-3000
Sapphire Radeon RX 550 2GB
@Kmpkt 's Dynamo Mini + HDPLEX 160W AC-DC
Samsung 970 EVO 250GB
Samsung 850 EVO 120GB
Seagate HDD 2TB
 

Mansen

Efficiency Noob
Original poster
Oct 13, 2020
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Choidebu

"Banned"
Aug 16, 2017
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The amazon link showed up alright.

For the rest: in paper, yes. Although if you're in the US of A I'd reccommend j-hack's combo units

That red cable is very misleading. Should have been yellow for 12V, red for 5V. Sheesh. But pinouts are okay - it is taking 12V.

I'd check for the barrell polarity though, if it is reversed you can just pull out the pins on the molex side and swap the red and black.
 

Mansen

Efficiency Noob
Original poster
Oct 13, 2020
7
0
Good to know. Europe sadly. Denmark at that which is worse in terms of import fees - The postal services will happily slap big fees on anything from outside the EU here. ?

(Very curious to see what the final price for the LVDS board I bought from China will be...)
 

Mansen

Efficiency Noob
Original poster
Oct 13, 2020
7
0
Oh that one is neat - Can't seem to find anyone selling them though.

Not that it matters. I chickened out with the "low" concerns wattage and bought a cheap (but respectable) SFX PSU, since there's more than enough room for it, with a motherboard tray on top in the case. It also happens to be half the price of a pico/hdflex solution and readily in stock.

Maybe for revision two when I have IO plates done for the back. ?
 

Stevo_

Master of Cramming
Jul 2, 2015
449
304
Oh that one is neat - Can't seem to find anyone selling them though.

Not that it matters. I chickened out with the "low" concerns wattage and bought a cheap (but respectable) SFX PSU, since there's more than enough room for it, with a motherboard tray on top in the case. It also happens to be half the price of a pico/hdflex solution and readily in stock.

Maybe for revision two when I have IO plates done for the back. ?

I got mine(actually 2 of them) from the place in the link below, you have to order the 120W as directed and they send the 150W though shipping may be prohibitive for you. https://www.atxpowersupplies.com/120-watt-power-supply-FSP120-50GNF.php