Question Malfunctioning 80W 12V DC Power Converter ?

[bit_user]

I have a mini-ITX case that has a 12V DC input and an 80 W converter board. When I connect it to my mini-ITX motherboard and plug in the external power, a red LED on the converter board alternates between a long blink and a short blip and the PC won't boot. I know it's not the motherboard, because if I power it with a known good ATX PSU, it boots fine.

Any ideas what's the issue? I have never successfully used it, so it's not as if it previously worked and has since stopped. I searched for documentation on it, but the only sort of model number on the board is LST-DC-ATX. Then, there's a big space (so it might be unrelated) and a V2.1. Underneath LST-DC-ATX, there's what appears to be a date: 20160928 (Sept. 28, 2016?). I bought the case back in 2017, so I don't expect I can get support on it, and I know they no longer use that same model of converter board.

The external power brick is made by Seasonic. I've also never used it, except for the last time I tried to use this case for a build. It has a green LED that remains constantly illuminated, while it's plugged into the wall.

One more clue: when I connect the external power brick to the converter, but without connecting the converter to my mini-ITX board, the red LED doesn't come on. I take this as a sign that the converter isn't complaining about the input voltage.

 

[Lutfij]

I have a mini-ITX case that has a 12V DC input and an 80 W converter board.
I'm assuming you don't have a link to the product. Can you pass on images for the internal PSU and the power brick's info?

What are you trying to power up with the adapter/brick?

 

[bit_user]

I have a mini-ITX case that has a 12V DC input and an 80 W converter board.
I'm assuming you don't have a link to the product. Can you pass on images for the internal PSU and the power brick's info?

The board & power brick are like this, but slightly different and I can't find anything like that model number printed on the board:

http://www.morex.com.tw/products/product_view_en/71
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The power brick is a Seasonic SSA-0601HE-12

https://seasonic.com/pub/media/pdf/industrial/datasheet/SSA-0601HE-SERIES.pdf
​

What are you trying to power up with the adapter/brick?

ASRock J5040-ITX mini-ITX board:

https://www.asrock.com/mb/Intel/J5040-ITX/index.us.asp
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The CPU is rated at only 10 W. The only things I have plugged into it are USB mouse, keyboard, and HDMI. I even tried it with only one DIMM, which is a configuration I verified using a normal ATX PSU.

 

[bit_user]

If you're curious, here's the case.

MITXPC MX500-USB 2.0 Industrial Fanless Mini-ITX Case w/ Wall Mount Bracket

The MITXPC MX500 supports Mini-ITX form factor motherboards. The enclosure is designed to fit an optional 120W powerboard or a 80W powerboard. The enclosure features a variety of mounting options such as wall mounting brackets, or an optional VESA Bracket for 100mm and 75mm patterns. The MX500...

mitxpc.com

It shouldn't be relevant to the issue. I made sure the boards were properly fastened to the standoffs and that there wasn't anything which could be shorting them on the underside (extra standoffs, stray screws, etc.).

 

[Lutfij]

By any chance are you working with a PICO style PSU. Can you gain access to another power brick, something from a Dell(Alienware)? For the sake of troubleshooting, see if you're able to get everything out onto a board, devoid of the case, in case the PSU's PCB might be shorting to the case...?

 

[bit_user]

By any chance are you working with a PICO style PSU. Can you gain access to another power brick, something from a Dell(Alienware)? For the sake of troubleshooting, see if you're able to get everything out onto a board, devoid of the case, in case the PSU's PCB might be shorting to the case...?

I've gone ahead and ordered a MX-0608F to replace this board. Maybe the board just never worked. I'll update this thread when it arrives.

I had a faint hope that someone might at least know what that flashing pattern meant, but it seems the most likely possibility is simply that the board is somehow bad.

Thanks for taking an interest.

 

[Lutfij]

Yeah I was going to suggest that perhaps the PSU PCB was what came defective, though looking forward to your followup. Just out of curiosity, how much is the PSU setting you back? I would've looked into something a little reliable, for the sake of longevity

 

[bit_user]

Yeah I was going to suggest that perhaps the PSU PCB was what came defective, though looking forward to your followup. Just out of curiosity, how much is the PSU setting you back? I would've looked into something a little reliable, for the sake of longevity

The replacement DC-DC converter board cost me $31 on ebay, shipped. I decided that, if ever want to use this case, either that or a Pico PSU are my only options. I guess there are a few mini-ITX boards that have 19 V barrel connectors built right into them, but the board I'm trying to use doesn't.

As for DC-DC converter options, the standalone board seemed like the better option, as it has cables for more peripherals. I also feel like such a diminutive converter as the Pico-PSU can't perform as well as a larger board, assuming they're both designed to the same standard.

The Seasonic power brick seems to be available for about $30, also. Hopefully, the one I have is good. I always use Seasonic-branded PSUs for my standard desktops. I hope their power bricks have comparable quality. The specs look good, at least.

 

[bit_user]

Update: the Morex MX-0608F arrived and is working beautifully with that same Seasonic power brick. I ran some stress tests (using stress-ng, on Ubuntu 22.04) for about 30 minutes, as well as 4 full passes of Memtest.

So, I have two guesses about what's wrong with the original converter board.

1. It's simply defective.
2. Because the DC barrel connector isn't mounted on the board, itself, maybe the board was actually designed for 19V input.

Note: Each converter board came with its own barrel receptacle and cable. They use the same 2-pin connector for attaching to the DC converter board (see below), so I assumed they were interchangeable and used the one already mounted in the case. To my surprise it turned out that the polarity of their internal connector is reversed! I verified that the new lead didn't work with the old converter board (it triggered the same fault-protection in the power brick), so the difference appears to be by design .

That just goes to show that you should check all assumptions. Luckily, the power brick had a short-circuit protection feature that surely saved it and my converter board, if not also the motherboard.

The fact that both converter boards are the same dimension and have the same mounting holes really makes me wonder if there's some kind of standard for it, or maybe it's just a defacto standard created by a couple manufacturers. I've seen a few other mini-ITX cases that seem to accommodate the same converter board setup.

Here are two variants of the new board. I have the top one, since there's no hole for the DC-In jack, at the spot in the case where the board mounts.

​

 

[Lutfij]

Thank you for awarding my post as the Best Answer!

 

[bit_user]

Thank you for awarding my post as the Best Answer!

You reached the correct conclusion, as far as I can tell*. Plus, you were the only one to take interest in my problem.

* I still can't rule out the possibility the board was for different input voltage.

 

[Lutfij]

you were the only one to take interest in my problem.
Just helping out, man!


* I still can't rule out the possibility the board was for different input voltage.
Could be, there have been instances of PCB's being wired the wrong way(blame the pandemic and pressure from an assembly line manager).

 

[bit_user]

* I still can't rule out the possibility the board was for different input voltage.
Could be, there have been instances of PCB's being wired the wrong way(blame the pandemic and pressure from an assembly line manager).

I ordered the case + converter + PSU in April, 2017. The company also sells preassembled systems, and presumably knew what they were selling me.

I have the invoice and it describes the external brick as "Seasonic 60 W/12V Level 6 AC Adapter". The internal DC converter is described as "80W DC-DC Powerboard with ATX Power Cable and DC Input Jack Cable". Since I can't find the specs for it online and they no longer carry that model of power board, it seems plausible that it's for the wrong voltage.

An interesting detail is that I had misremembered it as being 19 V. I think I actually ordered it over the phone, because I wanted to make sure I got the Seasonic power brick, as they also had a non-Seasonic brick, and perhaps that one was 19 V. Anyway, it's all in the past and I'm prepared to let it go. Someday, I might be tempted to try using it with a 19 V power source.