1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

HP Laptop Problem ZD8000

Discussion in 'Hardware' started by Come_On_You_Irons, Sep 24, 2007.

  1. Come_On_You_Irons

    Come_On_You_Irons Bit Poster

    33
    0
    21
    Hi all,
    I have acquired a HP ZD8000 laptop which seems good spec to me, the only trouble is it wont switch on if you press the on switch the LED's light up and fans begin to rotate for fraction of a second and then nothing.

    I now have it in bits with only the ram and battery connected and have found that if I hold power on button for 9 or 10 flashes of the blue LED's the machine briefly begins to fire up for perhaps 2 seconds and then again nothing.

    Any ideas?
     
    Certifications: A+, Network+, CCNA
    WIP: CCNP
  2. greenbrucelee
    Highly Decorated Member Award

    greenbrucelee Zettabyte Poster

    14,283
    254
    329
    Could be the CPU or maybe there is a problem with the battery, do you have spare battery handy just so you can test this, but I would be inclined to say the CPU is dead.

    Is there any other RAM you could use to test?
     
    Certifications: A+, N+, MCDST, Security+, 70-270
    WIP: 70-620 or 70-680?
  3. Come_On_You_Irons

    Come_On_You_Irons Bit Poster

    33
    0
    21
    Afraid I dont have a spare battery or RAM, I have a power adaptor but it does not even fire up if you hold the button in with that connacted (very confusing).
     
    Certifications: A+, Network+, CCNA
    WIP: CCNP
  4. greenbrucelee
    Highly Decorated Member Award

    greenbrucelee Zettabyte Poster

    14,283
    254
    329
    if its not firing up with a new power adapter then I reckon your cpu is knackered, this might sound strange but what does the mobo and cpu socket smell like?

    Is there a burning smell?

    if so then something had fried the cpu/mobo

    can you get a spare battery to try?
     
    Certifications: A+, N+, MCDST, Security+, 70-270
    WIP: 70-620 or 70-680?
  5. Come_On_You_Irons

    Come_On_You_Irons Bit Poster

    33
    0
    21
    No burning smell, and not sure it is worth forking out for a battery or not?
     
    Certifications: A+, Network+, CCNA
    WIP: CCNP
  6. MacAllan

    MacAllan Byte Poster

    249
    6
    30
    It could be memory, or the system board that has failed. I think you can rule out the battery if the same thing happens on the mains supply via the adapter. I doubt that it is the cpu.
     
    Certifications: A+, N+, CCNA
    WIP: CCNP, Linux+
  7. Come_On_You_Irons

    Come_On_You_Irons Bit Poster

    33
    0
    21
    I doubt if it is the cpu aswell, one thing I have just noticed is - when I put more charge into it it does seem to stay on longer, but it wont turn on with just the power adaptor fitted, and when i press the on button the charging light goes out until I wiggle the lead again, I am wondering if it is the solder that connacts the power socket to the motherboard.

    Would that make sense?
     
    Certifications: A+, Network+, CCNA
    WIP: CCNP
  8. greenbrucelee
    Highly Decorated Member Award

    greenbrucelee Zettabyte Poster

    14,283
    254
    329
    If the power is staying on for longer when you wiggle the leads then it is probably the contacts.

    But your PSU could be knackered,
     
    Certifications: A+, N+, MCDST, Security+, 70-270
    WIP: 70-620 or 70-680?
  9. Come_On_You_Irons

    Come_On_You_Irons Bit Poster

    33
    0
    21
    NOt sure it actaully is, now that I have it all back together, it does seem to stay on for longer but I am not totally sure whether it is due to the adapter or not.
     
    Certifications: A+, Network+, CCNA
    WIP: CCNP
  10. hippy

    hippy Kilobyte Poster

    307
    5
    40
    Had a similar problem with a Desktop. Was a duff motherboard.
     
  11. laddylam

    laddylam New Member

    1
    0
    1
    Hey Irons my name is Craig and I'm writing you from the States I saw your post and I have had a similar problem with not being able to power up my ZD8205US. I bought this computer brand new and it work excellent for about 16 months then it started giving me problems starting up. I would have to press the power button several times at first for it to turn on. This continued for a few weeks and then it would not power on at all. I let it sit for a couple of days and then I would try it again and it would magically power up. I called HP support and they told me that they felt I was having a build up of static electricity and that was causing the problem. They told me to disconnect the battery and the power supply and then hold down the power button for thirty seconds. I tried doing what they told me knowing the whole time this was not the problem but I wanted to cover all my bases. After telling HP support that this did not work they said my only recourse was to send it in for service at the rate of four hundred dollars. Now I'm not sure how many Pounds that is but it was too much money for me. I came across a person who works on computers on the side and called him up and explained the problem. He had me drop it off at his apartment and after he had a chance to examine the computer he found the problem and it was a faulty switch called a daughter board. It is the circuit board that is located directly beneath the power button. It is actually the power button underneath the plastic. He ordered the part from HP and it cost about $85 American dollars. This was about a year ago and I'm beginning to experience the same problem all over again. So please check this out and it may possibly be your answer. Please get back to me when you find out your problem.

    Craig Griesemer
    Albany, NY USA
     
  12. Tierneyeom

    Tierneyeom New Member

    2
    0
    1
    I doubt that the CPU is something I just noticed - if it seems to me most accounts, stabbed to stay longer, but it just re-applied only to the power outlet, and when I did the button lights up to my head maneuver, I'm curious to know if this is the main cable to the motherboard CONNACT welded.
     
  13. Bluerinse
    Honorary Member

    Bluerinse Exabyte Poster

    8,871
    167
    256
    Um.. this thread is 4 years old.. And, say what?? :eek:
     
    Certifications: C&G Electronics - MCSA (W2K) MCSE (W2K)
  14. aparsons

    aparsons New Member

    1
    0
    1
    I have one of these. It appeared to turn itself off on a hot day owing to overheating. Then it worked for only short periods. Now it will not turn on at all. The power light goes on on the front of the machine when the power cord is plugged in. When you press the power button the leds light for a split second and then the power light goes out. Have tried replacing the CPU and the fans are clean. It seems that some people have got these machines to go again.

    I know it is not the power button daughterboard as I have swapped this.

    On a "won't turn on" related issue, the HP power supply for the zd8000 is something of a special and there is a third pin that has to have the correct voltage on it for the laptop to work. The HP powersupplies eventually seem to fail and people buy the cheaper chinese ones which in theory should be fine. However in my limited experience these do not have the voltage on the third pin so the laptop remains dead. Then people (from the threads) logically think I've replaced power supply and the laptop is still dead so the laptop must be dead. Not so. Quite probably the laqptop is just fine, its just that the power supply is not providing the voltage on the third pin.

    Find a friend or a computer shop with a proper HP power supply and try the laptop on that before binning it - that is if you have not already lost patience and taken it out into the garden and shot it.

    A bit naughty of HP to do this as it misleads people and forces them for no good reason to buy an overpriced HP laptop unless they are prepared to modify (I did) a Chinese powersupply - and you know that you have to.

    Hope this helps and if anyone can shed light on the what the brief flash and not powering on means I should be grateful.
     
  15. Sideromelane

    Sideromelane New Member

    1
    0
    1
    Old thread I know, but I have a solution for this exact problem.

    I recently got my hands on one of these machines, sans power supply, or even power SOCKET.

    Some digging later, I discovered that there are indeed three pins, and one needs +19.5v, one needs to be 0v, and the third must be exactly 7.5v or the laptop will not power on.

    If you have a handy 19.5v two pin power supply, you can modify your laptop motherboard so that the +19.5v pin is shorted to the +7.5v pin through a 47kOhm resistor - this drops the 19.5v down to 7.5v and tricks the laptop into thinking it is recieving the correct supply from an original HP power pack. Then just stick a normal 2 pin socket in the space, I used polymorph plastic to ensure a snug fit, and a normal 19.5v two pin power pack will let the laptop power up and charge the battery as normal.

    The exact layout of the pins is tricky, I had to gently sand off the green screening layer to see the layout of the copper, but it's roughly:

    [+19.5v ]
    [+7.5v] -- This is weirdly sandwidged between the positive and negative rails and is a fiddly b*gger to solder.
    [ -V ]

    By default there should be a 0.03ohm resistance between the +7.5 and 0v rails and NO connection between +7.5 and +19.5
     

Share This Page

Loading...