Problem with an HP desktop

By AdelN
Oct 19, 2007
  1. Hi All,

    New to this forum, hope someone can help.

    An HP a405n computer about 3 years old, bought new, never had a problem.

    Today we had a power failure, I unpluged the computer before I left the house. When I got back and repluged, the power switch on the front only flashed (no other sound like fans ..etc). A green light also flashes on the back, but that is all. No mention of this problem in the manual?
    Any Ideas?

  2. jmjsquared

    jmjsquared TS Booster Posts: 144

    Sorry to say, but I am pretty sure your motherboard has been damaged.

    The "green lights" you mention: Is one on the rear, main power supply and the other on the front panel near the power button? Does the rear light start flashing even before you push the power-on button in front?

    Did the power outage happen while the computer was running?

    If the answers are "Yes", I think you should order a new board from HP. They retail for about 86.00USD. I've replaced two on same series machines in the past six weeks. So, I am not giving careless advice.

    But, before you do that, look here for my recommendations for a similar problem. The troubleshooting procedures for your issue are the same, except that you should first try another power supply and one new stick of memory. You will have to find the CMOS pin location at the HP site (It's very late here and I am tired.)

    Let me know how things work out.

    Good luck.

    -- JMJsquared
  3. AdelN

    AdelN TS Rookie Topic Starter

    Following the instructions on the HP website, it indicates that the power supply is shot! I took it out. Is that the kind of item that can be bought from Fry's or .... or do I have to order it from HP?

  4. zipperman

    zipperman TS Rookie Posts: 1,179   +7

    You can buy them from any computer Smart-Buy or Best Buy.
    or Frys.Minimum of 400 watts.You probably had less.
    But get a good surge protector power bar at the same time.
    Mine even protects my telephone.$ 10,000 insurance included.
    A city like San Jose should have many computer stores.
    HP support is one of the best,call them.
  5. AdelN

    AdelN TS Rookie Topic Starter

    Thanks Z,

    This one is 250 watts, I go out tomorrow and buy one. Prefer to do that rather than mail order from HP. Hopefully I'll have it running by tomorrow.

  6. jmjsquared

    jmjsquared TS Booster Posts: 144

    Before you buy anything...

    I went through HP's procedure TWICE on two different systems with the same Power Supply/MoBo combination as your's with no positive result.

    I strongly suggest that you test/try another power supply to confirm HP's advice before spending money on anything!

    You can do this without much trouble: Open your case, disconnect the two connectors from the power supply to the motherboard and try the "test" power supply. Since the supply is grounded, you can use the "test" supply without permanently installing it first.

    If you decide to buy another supply anyway, buy a "switching" one rated at least 350W - 450W, as zipperman suggests.

    I hope I am wrong.

  7. Tedster

    Tedster Techspot old timer..... Posts: 6,000   +15

  8. AdelN

    AdelN TS Rookie Topic Starter

    I just bought a new 500 watt PS and popped in the computer and its working fine. I followed the instruction for that particular computer in the trouble shooting section on the HP website and it lead me to a bad PS which turned out to be true.

    Thanks for everyone's help.
  9. jmjsquared

    jmjsquared TS Booster Posts: 144

    I am glad I was wrong.

    Enjoy you new-found power!

Topic Status:
Not open for further replies.

Similar Topics

Add New Comment

You need to be a member to leave a comment. Join thousands of tech enthusiasts and participate.
TechSpot Account You may also...