[New Upgrades] PC turns on for a second just to turn off

astuka

Distinguished
Apr 3, 2014
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18,515
Hello,

I think (hopefully) I know the problem to this, but seeing as I'm fairly a novice at this I'd like someone more experienced to confirm. I recently added some new stuff (mobo, cpu, graphics card, RAM) to my computer. It took a very stressful and long time and ended abruptly when I heartbrokenly found out that it wouldn't boot up. However, nothing else really seemed to shoot out at me -- it seemed like it was going to be a totally normal boot up before it stopped. So here was my hypothesis:

The only part that I didn't change, the PSU, did not have enough wattage to support the rest of the computer. The mobo read this, and immediately turned off to prevent any damage.

Now I just need to know some stuff to confirm:

1. Is this the most likely thing that is happening? If not, what is?

2. I turned it on and off twice before I figured out what was wrong. I know its only a little bit, but is there any chance I might've damaged anything in the process?

3. IF it is the PSU, what amount of wattage is recommended for this build?

Sapphire Radeon R7 240
Intel Pentium G3220 3.0Ghz
MSI H81M-P33 MOBO
4 GB of RAM

PCPartPicker says 145 I believe, but it might need higher (the PSU itself is from the original prebuilt and has no markings signifying wattage)

4. IF it is the PSU, what store can I go to to quickly pick up a new PSU? I spent 10 days waiting for all these parts to come in, and I'd rather not wait another 5 waiting for a PSU :p


Edit: While looking at some PSUs I've noticed some refer to either being a ATX or Micro-ATX power supply, and I was wondering -- is this refering to the case of the mobo? If the latter that might also be a reason as the original mobo was ATX but this one is the micro.
 

astuka

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Apr 3, 2014
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18,515
Alright, after finding a few more posts more similar to my problem saying it was just the PSU, I decided to go ahead and get the PSU. Yet now that I have it, it won't even start for a minute! The power button does literally nothing. What's going on?
 

zlayerz

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Mar 24, 2014
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4,530
I take the power button you refer is the one on the case? Can you turn it on with the power on switch that come in most motherboard, Im no expert but i would start there

What you need to know is what kind of power the mobo need a 20 pin or 24 pin mobo