JetWay JNC9C-550-LF and PicoPSU-90 problems


I got a Jetway JNC9C-550-LF mini-ITX mobile Atom board from Newegg to run, and the plan was to run it off a Pico-PSU 90W [amzn] power supply for maximum efficiency.  But I could not get the darned thing to boot on that power supply.  It worked ok on a 250W ATX ps, though.  I had originally gotten an 80W picoPSU, and that failed to boot, so I RMA’d it.  The folks at mini-box were very nice and helpful, but the 90W behaved exactly the same way.  I was stumped.  As a long shot, I asked Jetway tech support about it, and was rather astounded to get this reply:

(reposting here in the hopes that it will help others)

Dear customer,

Thank you for taking the time to write to us with your concerns. I am happy to assist you further.

We have reviewed your request regarding JNC9C-550-LF. According to your statement, we think it is something related to the power supply.

We have experienced some minimum load issues with the following power sources:
1. IEI ACE-4518AP
2. PicoPSU-90
3. M3-ATX 125W
4. Power-win PW-085B-5Y

Our solution for above powers is:
1. remove D9
2. remove R163
3. change Q30 from C01-E7002-F to C04-EAPM2300A-F
4. change R270 from E01-42B1.8K-F to E01-42B3.3K-F

You can try to remove D9 & R163 first. Our test has shown it can work with picoPSU when only remove these two parts.

We hope this update has been helpful. However, if you have any additional questions, please don’t hesitate to contact our Technical Department.

Best regards,

Jetway FAE / Tech Support Team
Jetway Computer Corp.
38507 Cherry Street, Suite E
Newark, CA 94560

I’m rather amazed that they would suggest reworking the board, and I’ve asked what this will do to my warranty (!) and whether newer revs have this fixed.  Still, this is quite an interesting reply IMHO, I didn’t expect to learn this much!  They also attached pictures of the components:

I don’t know if I’ll go after it with a soldering iron or not, but at least the mystery is solved!

Update: Jetway tells me that newer boards have this problem solved.

Update 2: It works!  Removed the diode and the resistor and it’s booted up fine.  20W server here we come!

11 thoughts on “JetWay JNC9C-550-LF and PicoPSU-90 problems

    • I’ve considered ARM boxes, but storage is always the issue for me, at least with anything affordable. Can I hook 4 drives to that thing (and if via USB, what does that do to my power budget with 4 wall-warts?)

  1. Wow, so I took a deep breath, broke out the tweezers and the low-wattage soldering iron, and tried the suggested removal of the 2 components:

    1. remove D9
    2. remove R163

    and … it worked! Booting up with the pico-psu 80W, 1×2.5″ and 2×3.5″ green drives.

    System is at about 30W while booting, 25W when booted, 23W after a little tuning, 18W when the 2 big drives spin down. Woohoo!

  2. Hi Eric,

    It’s probably a issue because they are still unabordable but these new SSD drive seem to be perfect for your resident main OS. Their consumption don’t go over about 0,8w even if they are full solicited and more, they have outstanding performances.

    Either, even if they get old quick because of their writing problems, I think they probably are more reilable than motorized drive and you are not obligated to build a raid system. Less drives, less consumption.

    • I did consider an SSD root drive, and you are right, they would probably use less power. But cost was a primary consideration… I simply have very little trust for the “cheap” SSDs, and the ones I trust are quite expensive. For now, it’s laptop drives… they seem reliable, affordable, and pretty efficient.

      Maybe someday …. :)

  3. While I can understand having little trust for “cheap” ssd’s It makes a big difference in performance response time of even a *nix server.

    I have a 32gb Corsair SSD that I picked up used for 50 bucks off of the [H]ard|Forum FS/T forums as the boot drive in my server running Fedora 14 w/ amahi & a 10tb greyhole array (spread between 6x samsung eco drives). Having the OS on the SSD has at-least to me proven to be much snappier then when the OS was previously on one of the storage drives. Simply the wake-up time between accessing a dormant drive & transfers beginning seem to be much faster which is I believe due to the SSD not spinning down so it can immediately start the spin up process of the needed drive without having to spin up itself.
    I have no proof of this, but I suspect that this probably improves the overall effeminacy since there isn’t a 2nd mechanical drive pulling excess power when its not needed.
    On a Side note that is a quite impressive little build you did there. I had similar a while back using an Intel d510 atom board with 3x samsung eco drives before I decided I needed more power (was hosting SageTV on the server) and moved up to a used Phenom 9150e (65w tdp 1.8Ghz quad).

  4. Hi Eric,

    I have made some tests since two months with a laptop “ACER ONE D255” who’s holding a single Atom N455 with 1 GIG of DDR3 RAM. I’m using it for the “remote desktop” capabilities with Window 7. Well, I guest it should be enough powerfull to run a small Web site.

    I checked for days the consumption with my “kill-a-watt” meter and I mostly get about 5w in idle time and about 12w in hard working time (with the screen turned off since I don’t need it).

    I should say that I have made some others test with Ubuntu 10.01 LTS for server purpose but I admit that my knowledge in Linux is limited. So I didn’t find out how to use the power management quietly right. Well, In Idle time with Ubuntu 10.01 LTS, the less I got in consumption is around 10w. So, It’s about twice much than Window 7. I think that the Ubuntu 10.01 LTS packages hold not right the last power management features of these CPU. But I’m not sure.

    Finely, my point is that is someone is looking for a very low power consuming X86 computer, the N455 seems to be a good option.

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  6. Really appreciate your blog article as I ran into the same problem with picoPSU. My version of the NC9C-550 did not have (as far as I could see) the R163 but did have the D9. I removed it, and picoPSU now powers the board. Thanks!

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