Computer doesn't start Motherboard or Power Supply?

By felixcat ยท 30 replies
Jan 21, 2005
  1. Hi everyone- This is my first time here and I need help!! I'm a newbie and not real technically advanced, but here's my problem... A few days ago I was trying to connect my scanner to a USB port and I noticed my mouse got stuck. I hit the power button on the front of the computer to turn off. I rebooted and then I couldn't enter my windows password because my keyboard didn't work either! I then turned off the computer from the reset button in the back. Then I flipped it back and tried to power on my computer and it has never turned on again! I should mention that when I try to turn on the computer there are no sounds, no fans moving. It's just silent and dead. It doesn't try to do anything. Could it be the power supply or motherboard? I tried using different outlets, and changed out the computer cord that runs to the outlet. My friend helped me build my computer about 2 years ago. I have left it running mostly 24/7, which I guess isn't good. Could I have worn out my computer faster? I don't even remember what kind of mobo I have or really anything (I have to look and my friend ordered the parts 2 yrs ago). The only repair I've ever had to do on it was replace the fan about 8 months ago. My friend instructed me to open up the computer and see if the wiring from the power button to the motherboard looked ok and it looked fine. I just wonder if the keyboard/ mouse problem first gives any hint to what could've happened. There were no weird sounds, no smells, nothing burned (that I could tell.) My friend and I are going to look at it this weekend, but we could use some advice! I am going through computer withdrawal at home! (am posting from work right now.)
    Oh, regarding the scanner, I guess I should mention that my USB port I was trying is in the front of the computer below the power button. However, I noticed I can't fit it in the USB port anymore because it's bent or something. Maybe this did something to affect the power button itself? So I never succeeded in getting the scanner in there because it didn't fit in the "bent" USB port, then the mouse froze, etc. Then I was checking my cords in the back to the mouse and keyboard and then the whole non-powering thing happened. I also tried a suggestion where I unplugged the power button from the Mobo and put a dime on top of the two pins to try to power it on and nothing happened.

    Help!! I'm desperate.
  2. vegasgmc

    vegasgmc TechSpot Chancellor Posts: 1,377

    It sounds like there was a short in the USB port and it damaged the motherboard. There is electrical current running through the USB port.
  3. edmundtran

    edmundtran TS Rookie

    Hi, I have a suspiciously similar problem to you. You may have noticed my posts on this website.

    My prob is exactly the same almost, no power, no nothing. I have 2 usb slots, one on top of the other on the front of my computer, and recently the bit of metal seperating them has been bent out of position. Although i can bend it back into position, my computer still doesnt turn on nevertheless. The day my computer decided to do this, I had a USB cable inside one of the front USB slots. I dont know if this is significant but I just wanted to post to let you know. The troublesome thing is that I've been using that cable several times before the computer died.

    The main difference between yours and mine is the fact that yours showed signs of distress and mine just went randomly one day.

    This post probably doesnt help but at least you know theres someone else with the same problem!
  4. dobygirl301

    dobygirl301 TS Rookie

    I seem to have the same problem as well. Mine started with an ethernet connection though. Regardless, it turned out to be the power supply, however now I think that it somehow fried my motherboard as my system locks up right after booting...good luck!
  5. felixcat

    felixcat TS Rookie Topic Starter

    I thought I replied to the posts, but I don't see my reply. hmm...
    Thanks to everyone for your thoughts on this issue. Unfortunately, several of us are going through this problem. I tried a new power supply over the weekend and it didn't help. I have reordered my motherboard, but it was 2 yrs old so I had to find it on ebay because nothing was compatible. I'm just afraid that if the USB port fried the motherboard, could the RAM have gone as well, or even the processor also? Yuck! :( I'm eagerly awaiting my mobo in the mail now... will keep you guys posted.
  6. edmundtran

    edmundtran TS Rookie

    I've sent my motherboard for testing, hopefully It'll be fixed. Problem is, if theres nothing wrong with it, I get charged. I'll keep updating on this situation. I have the same worries about all my other components also, felixcat. I really hope all my other components are ok!
  7. felixcat

    felixcat TS Rookie Topic Starter

    My new motherboard is supposed to arrive today, however now I'm wondering if I need to buy a new case because the wiring could be messed up- esp from the front USB port. I don't want to use those front USB ports again! I really hope I don't have other components messed up as well. Edmund- Keep me updated what they find out about your mobo.
  8. edmundtran

    edmundtran TS Rookie

    One thing I forgot to mention, dunno wether this is relevant but on my old computer, If you unplugged the USB cable when nothing is connected to it, the computer would restart itself. This was also a front USB slot. Seems that computers are quite funny when it comes to these things.
  9. Dcrewchief

    Dcrewchief TS Rookie

    try unplugging your front usb ports from the header pins on motherboard and see it powers up. just a thought maybe it will work.
  10. edmundtran

    edmundtran TS Rookie

    If my memory serves me right, I think I may have already tried that and failed. But thanks for you insight into this! Anyway if the motherboard was fried as a result it would'nt have worked even if that was the problem...

    It is looking more and more like a USB problem though!
  11. kpc1280

    kpc1280 TS Rookie

    turn it off first

    I may be wrong but I`m thinking You should turn off your computer before you plug in any new components.
    I know that some say plug and play and you should be able to just plug it in and play but I really think some computers are quite fussy about these things. and if you don`t have the proper power surge protector then the it`s possible to fry you motherboard by pluging in a new component without turning it off first.
  12. Caerbannog

    Caerbannog TS Rookie

    Front Panel USB Problems

    Plug and play should work fine with the front USB problems but I have seen people connect these front panel USB ports incorrectly in the past. Unlike some of the rear USB add-on modules which generally have block type connectors that really only plug in one way I have seen a lot of exceptions to this for front panel USB.

    I have one case that has two seperate connectors. Not too bad to figure out as one connector has 5 pins and the other 4 pins. It is obvious which connector goes on the top and which on the botton but if you don't watch which pin is VCC you can put them on wrong and mess that up.

    Another case I have came with 9 seperate pin connectors one set of 5 with two ground pins labeled VCC-1 through GRND-1 and the other a set of 4 labeled VCC-2 through GRND-2. This kind of configuration is much easier to get a pin wrong on by mixing up the - Data and + Data pins etc. If the person building the system is not careful he could set it up to fail when a device is plugged into the port.
  13. felixcat

    felixcat TS Rookie Topic Starter

    Computer fixed!

    Hi everyone,

    My computer is now up and running again! Whoo-hoo! My friend and I fixed it this weekend. I started this post by asking "power supply or motherboard" - well it turns out it was both! I replaced the mobo with the exact same one (found it on ebay). But when I'd try to power it up, fans would run and then turn off before not much else could happen. So I replaced the power supply as well and now it's working fine again! I'm so happy to have my "baby" back. I had tried replacing the power supply only at first and it didn't help. But it looks like I needed the combo replacement. Thanks for everyone's posts and good luck to those with similar problems!
  14. edmundtran

    edmundtran TS Rookie

    Nice one felixcat, good to know something good came out of this. Shame you had to buy another motherboard though. I'm still waiting for my supplier to do something with my motherboard..

    About the USB pin things, I have the complicated one with 9 pins all seperate. If you plug it all in and the USB seems to work ok, could it still be in the wrong way? And does a failure only occur when data 1 and data 2 are mixed up?
  15. overgaard

    overgaard TS Rookie

    Hey you guys...

    I do not know it anyone still reads this this thread, but I have a similar problem now, and I am trying to find aout the reason, so here it goes...

    One month ago my computer wouldn't start. I tried to put another power supply into the computer, and it helped. I wasn't satisfied with that, since the other power supply worked fine with the machine from which had taken the other! Therefore I put the first one back in again and started pulling out devices.

    I have heard that some power supplies recieves a small electric current from the devices to let the power supply know if they are OK. Can anyone confirm this?

    Anyways, I found that when you pull out the devices you have to turn of the computer and let it discharge before attempting to start. My motherboard has a small green lamp which has to stop blinking.

    If I followed this rule I found that the netcard (ethernet) was causing the problems so I bought a new one, which fixed the problem. No new power supply, and no new motherboard...

    ... that is, probably until now! I have the same problem now. When I try to power it up it rotate the cooler very shortly, and then nothing happens. Aha, I thought... then I will just do as I did a month ago. Nothing helps!

    I really would like to find out what the problem is, therefore I have some questions. It seem like it is my USB something that caused a problem, since I turned of my computer this morning brutally after plugging in my iPod mini. Therefore I though that it might be one of two reasons...

    - Do any of you that posted in this thread with the same problem have an iPod?

    - Do any of you that posted in this thread with the same problem have a seperate card connected to your motherboard, which supports USB 2.0? I recently bought this card since the computer did not support 2.0 which is required for iPod mini.

    Thanks, any input is appreciated, Overgaard.
  16. rdmcmains

    rdmcmains TS Rookie

    I am having a similar problem with a computer I just finished building. I flip on the power supply, and the lights on my keyboard come on, but when I hit the power button, all that happens is the HD LED and an LED between the RAM slots and the CPU flash, and the CPU fan spins briefly. I can't tell if the power supply fan is operating at all, and I can't figure out if anything else might be wrong with it. Any help here would be hot.
  17. jimli2008

    jimli2008 TS Rookie

    I think your RAM and CPU are good, May be you can use a good PC to test your RAM and CPU(for CPU,you need same model as yours), make ture they are work.

    Good Luck ,
  18. 0009

    0009 TS Rookie

    well well well...i had the exact same problem. the usb shorted out the mobo. i was charging my ipod and the wires got bent out of shape. i tried to fix them into position and i charged it up, then on my desktop it showed device not connected, i was like what? 1 day it was good another it just got worse. so i kept plugging it in and boom system restarted. lagged at the windows screen. i took it to best buy and they said it was the power supply...well it wasnt it was the mobo. the usb electrical current zapped my mobo and i had to send it back where i bought it. from then on i dont use my front usb ports, i took the whole thing out of it, unplugged it from the mobo and unscrewed from the caase and i still cant really use any of my back ports, only for charging...
  19. baseball0085

    baseball0085 TS Rookie

    Mine has similar problems, but 1 exception i can turn on my computer just no response on keyboard, mouse, monitor, etc. Im pretty sure its mobo but im just checking.
  20. Psyrus

    Psyrus TS Rookie

    I've had a similar experience where the PC MB had power (LED on). On power-up the PSU fan would spin up, then stop again. Someone had also suggested that the components "signalled" the PSU and if a problem arose (generally with the MB) that the system would shut down. This, however, was not the problem here. We replaced the PSU first (cheaper option :) ) and that sorted us out. Follow the path of power... Plug...PSU...M/B... etc.
  21. lehsstudent

    lehsstudent TS Rookie

    alright i had the same problem...i think...
    ok its either power supply or its the jumper thingys
    you know where the power hooks up, hd led... its probably hooked improperly i had the same thing happen so i got experience
  22. tweakboy

    tweakboy TS Guru Posts: 467

    Most probably PSU is dead ,,

    Does the fans spin on PSU ? ,,, mobo culd be fried also,
  23. JCW

    JCW TS Rookie

    Try this:

    If the power supply power indicator light is blinking. Unplug the power cord from the computer. Open the tower and unplug the the big plug from the mother board. Plug the computer back in, the indicator light should be steady now. Now carefully plug the big plug back into the board. Make sure that your keyboard, mouse, and video connectors are connected. Now turn on the computer. If this works then you will need to get another power supply. Be advised that you cannot just go and purchase any power supply. These power supplies are different than the many generic types that you can purchase off the shelf. The best way to match it is to google. for example; if you have a pavilion a510n computer you would search for "Pavilion a510n power supply" without the quotes.
  24. lehsstudent

    lehsstudent TS Rookie


    I think that the reason i cant get it to work is innexperience(im 16 and have 1yr edu). the psu i used doesnt have an ATX 4pin 12v....
  25. JCW

    JCW TS Rookie

    The PSU must be compatible

    If your MB uses the 4 pin 12v. Then you must use a use a power supply that has it. Remember that Dell, Compaq, and many other brands don't use generic PSU's
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