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  • #2180755

    HP ZV5000 shuts down right after poweron

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    by k_c_v ·

    Hello.

    Having issues with an HP ZV5000

    About 2 months ago, an aging 14.8 volt 6.0Ahr HP battery was replaced with a new 14.8v 6.6Ahr unit. About a month afterwards, the unit began shutting down right after turning it on.

    On A/C power only w/ no battery, the unit does not power on but instead a very quiet clicking noise & high pitch whine is heard from the area of the a/c jack/cooling fans. The LEDs blink dimly with this noise.

    On battery power only w/ no a/c, the unit turns on long enough to engage both cooling fans, blink the LEDs, then shut down. The faint clicking is not heard.

    On battery + a/c power, the unit usually turns on long enough to display the HP logo, activate LEDs, engage fans, and then shut down. The clicking sound is not heard.

    I have checked the A/C jack for melted solder points, switched old & new battery, attempted boot w/o harddisk, and looked for dust inside the unit (fans, heatsinks, ect all vry clean). I’ve also verified the PSU by plugging it into a compaq laptop with similar voltage input specs, it worked.

    It seems this is a mainboard issue, but I’d like to identify which components are damaged, and the cause.

    What symptoms might a bad voltage regulator have?

    Any help you can provide is appreciated, repair quotes have simply been too much. My goal is therefore to fix the unit, and prevent reoccurance.

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    • #3159538
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      Reply To: HP ZV5000 shuts down right after poweron

      by hal 9000 ·

      In reply to HP ZV5000 shuts down right after poweron

      Have you checked the voltage coming out of the Mains Adaptor?

      Have you also checked the voltage that the Battery actually has?

      Sounds as if the Battery isn’t being charged and that it is now flat.

      As you have a 14.8 V DC Battery you should be getting something like 16.8 to 18 volts DC minimum from the Mains Adaptor. If you are gating that you can look at the Bridge Rectifier just after the Mains Adaptor or at least it should be close to where the unit plugs in this can either be a square IC with 4 legs with 2 AC signs and a + & – sign on its top or 4 Diodes one could be blown. Either way I would recommend replacing the entire thing either the one case or all 4 Diodes. After the Bridge Rectifier there should be a Zenner Diode which could also be faulty.

      If it is the Zenner Diode replace it with a Higher Current one as the obvious thing here is that it failed because of the higher current that the battery carries. You can keep it to around 17 V DC but with a higher current rating than the one currently in there.

      Col

    • #2963501

      check voltage after Diodes PD45 PD46

      by to.ka ·

      In reply to HP ZV5000 shuts down right after poweron

      Probably to late for your case,
      but maybee interesting to others:

      See http://techrepublic.com.com/5208-6230-0.html?forumID=48&threadID=194117&messageID=3081057

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