New Build no power-up: case's power supply or MB?

By Row1
Oct 22, 2014
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  1. Hello, everyone - I have just assembled a new build. It will not power up. I need a suggestion to figure out if the problem is the case or the motherboard.

    This is a mini-itx build. The case is Linkworld LC820-01B. This case comes with a 12 volt 65 watt external, laptop-style power supply that plugs into the rear of the case just like a laptop power supply plugs into a laptop - a barrel connector. Inside, this power connection connects to a power supply component that is not like a regular ATX power supply, but is on a printed-circuit board mounted on the case. This has several capacitors and other stuff. From that comes the 20-pin and 4-pin power supply lines for the motherboard.

    I assume the 12-volt power supply for this external power supply unit is right, since it came with the case. It was 65 watt.

    The processor is an IBM 1155 3220t, with TDP of 35 watts. Lower-powered CPUs can be put in a small 1155, so I assumed the power supply might be under-powered. I ordered a 90-watt 12 volt power supply with the right size barrel - and same polarity (pos inside).

    The MB is an ASRock H61MV-ITX. It is 1155, mini-itx form factor.

    Still, same problem.

    Everything is connected correctly.

    When I press the power-on button, an external CD drive I have plugged-in spins up for a while. But no power light comes on in the front of the case, there are no POST beeps, the fan for the CPU does not spin up. No other signs of life.

    So, power is getting into the MB - the external CD drive is plugged into a USB socket in the rear panel of the MB.

    After trying a 65watt and 90watt power supply, I believe the problem cannot be the power supply cord.

    Can it be that I have too little load? I don't think so. I plugged in another 90mm fan and an ol-fashion floppy drive (just the power connection) to add more load - same thing: no power-up, no POST, nothing, but the CD drive will spin up when I open-then-close it yet again.

    So, here is the help I need:
    [ ] what else can I try? -assuming the MB and case are fine?
    [ ] is it more likely the case/power supply is bad, or the MB?

  2. Row1

    Row1 TS Guru Topic Starter Posts: 326   +13

    Well, I figured out the problem.
    I am planning to re-do the older mini-itx system I have; it has gotten riddled with Trojan software for kids downloading games; it basically has been de-commissioned already.

    So, I took the pico-psu power supply from that older computer, and hooked it up to the one I am making. Everything went perfectly.

    So, I un-did that, removed the MB from case, disconnected the barrel-power connection from the case, unscrewed and removed the power supply that had been mounted in the case, put the pico-psu power supply back in place (I had to drill the hole for the barrel-connection out to be a little bigger since the pico-psu internal/external connection is threaded and held in place by nut with lock washer), and routed wires to be clear of cpu fan, screwed MB to stand-offs, and closed it all up.

    now, everything is great. I like this linkworld case, but the power supply is worthless. I may try to get a few dollars back from the ebay vendor, to make me happy with a case that is less than what I should have gotten, but is working for me; I don't want to wait on returns, etc.
    SNGX1275 likes this.
  3. Row1

    Row1 TS Guru Topic Starter Posts: 326   +13

    This computer is working great. We are using it for audio processing. It has high Windows Experience scores, except for the video, as we are using the onboard video as planned all along. The small case is really a great feature in the home. The only problem is it is so light - when you go to plug in a USB, the case will move around. But if you have low-power CPU, like this one, at TDP 35watt, you don't have to fret about cooling that much - so you can put something on top of the computer to weigh it down; covering the top air intake grid leaves you with the two on the sides, which is more than adequate.

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