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CMOS Timer Error with old laptop : DECpc 425 SLC

Discussion in 'Laptops' started by beltrixx, May 1, 2010.

  1. beltrixx

    beltrixx Guest


    I was given a very old laptop by a workmate, a DECpc 425 SLC (also
    known as Olivetti Philos 48) because I recently started collecting old

    This pc refuses to boot and displays the message :

    CMOS Timer Error
    Unrecoverable Power-Up Error

    I thought it was a problem of the batteries and replaced the 7.2V 60
    mAh with a new pack I made from two 3.6V 60mAh batteries but the error
    remains the same.

    My hardware knowledge is limited (I'm a programmer) so I would
    appreciate any ideas on how to proceed with this error if anyone
    thinks that there is a chance to fix this old treasure ;)

    Thanks in advance,

    Manel (beltrixx)
    beltrixx, May 1, 2010
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  2. beltrixx

    Sjouke Burry Guest

    Take the batteries out(including the power batteries), wait a few hours,
    put all the batteries back in, and hopefully cmos settings are back at
    factory default.
    Sjouke Burry, May 1, 2010
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  3. It is a battery problem, but were messing with the WRONG BATTERY.

    The battery causing this problem is an internal battery on or connected
    to the motherboard. Disassembly is probably required to even get to it
    (it could be on the bottom of the motherboard; motherboard removal may
    be required). The battery may be soldered to the motherboard, and it
    may be proprietary and no longer available, although a technician should
    be able to configure a working substitute. WARNING: DO NOT try to
    solder directly to a lithium battery. The resulting fire and explosion
    could be extremely hazardous (it's amazing how much damage the
    "shrapnel" from an exploding coin cell battery can do ... for example,
    to your eyesight).
    Barry Watzman, May 1, 2010
  4. beltrixx

    beltrixx Guest

    Thank you Barry,

    I had noticed another battery, a VL3032 Rechargeable Lithium, but I
    though it had nothing to do with the power-up error. I'll follow your
    advice and try to buy a replacement one.

    I'll let you know if finally I get this old marvel working.

    Thank you very much.
    beltrixx, May 2, 2010
  5. Why do you assume that this is a rechargeable battery? Most of these
    are one-time lithium batteries that are supposed to last 6 to 10 years
    in that application. Are you certain that it's not a 2032 instead of a

    [For these batteries, the first number is the diameter in mm (2032 =
    20mm across), the second number is the thickness in TENTHS of
    millimeters (so either 2032 or 3032 is a 3.2mm thick battery). I'm not
    aware that there is a 3032; 2032's are very common. The question is, is
    it socketed or soldered with spot welded tabs?]
    Barry Watzman, May 2, 2010
  6. beltrixx

    beltrixx Guest


    Yes I'm certain that it is a VL3032 one. Googling for "VL3032" I have
    found references to Lithium-Vanadium rechargeable batteries but I
    don't know for sure if the one in my laptop is rechargeable or not.

    The problem is that the laptop is rather old (17 years) so it is
    almost impossible to find technical docs or info regarding such a
    specific issue like this and I don't know if this battery can be
    replaced by a standard CR2032.

    Please, have a look at these pics of the battery :


    Do you think it can be replaced by a standard CR2032 or CR3032?


    Manel (beltrixx)
    beltrixx, May 2, 2010
  7. Well, the nice thing about this is that you have wire leads to a plug,
    so you can cut off those leads and deal with the replacement in whatever
    manner works best. You don't need an exact mechanical replacement.

    what are the dimensions of the BATTERY (I'd cut off the shrink wrap to
    measure this as accurately as possible). Normally, the 3032 number
    would suggest 30mm x 3.2 mm.

    The next issue is, is this a "one-time" battery or a rechargeable?
    Another reason to cut off the shrinkwrap is to see if there are any
    numbers on the battery itself.

    BIG DANGER HERE: If you replace a rechargeable with a one-time, it may
    explode when the laptop tries to charge it.

    Cut off the wires, insert the plug into the socket, and see if there is
    any voltage coming out of the ends of the wires (that would go into the

    Several sources suggest that it IS a rechargeable battery:

    Barry Watzman, May 2, 2010
  8. beltrixx

    beltrixx Guest

    Good advice!

    I'll cut off the wires and will use a multimeter to measure the
    voltage between them. It seems the best way not to make a mistake
    buying the wrong battery type.

    Thanks a lot,

    Manel (beltrixx)
    beltrixx, May 2, 2010
  9. beltrixx

    beltrixx Guest


    I've checked that the voltage between the wires (without the battery)
    is about 3V so the battery must be rechargeable. Also, every time I
    placed the tester tips on the wires a reset happened. Is that normal?

    I'll look for an appropiate battery and try to leave the laptop
    charging an entire day once I have installed it, if nothing else is
    damaged it should work perfectly.


    beltrixx, May 3, 2010
  10. beltrixx

    beltrixx Guest

    I'm starting to think the problem has nothing to do with the
    batteries. I tested the voltage of the Lithium VL3032 battery and it
    was about 2V (the battery holds a charge and seems able to be
    charged); I also left the computer without any battery and the error
    displayed was the same.

    The laptop was unable to power on and I thought it was a problem
    related to the resume function but maybe the problem is related to the
    motherboard. Neither the power button nor the sleep button (the one
    that is clicked by the screen when you close it) work, so to start the
    laptop, I must click the reset hole and after a few seconds is when
    the CMOS Timer Error displays. This can be a clue for some motherboard
    related error, isn't it?

    I'll put back all the batteries but there's little more I can do with
    my hardware knowledge ...

    Anyway, thanks everybody for helping me with this old computer.

    Kind Regards,

    Manel (beltrixx).
    beltrixx, May 4, 2010
  11. beltrixx

    Pen Guest

    Compaq/HP has some Docs for this, but they need to be
    expanded onto a floppy, which I don't have access to at this
    time. Therefore, I don't know how helpful they may be, but
    here's a link.
    Pen, May 4, 2010
  12. beltrixx

    beltrixx Guest

    Thank you Pen, but I did know about this download page and I used it
    to download the drivers some time ago. The docs are in fact, for the
    386 version of the same computer and do not provide information on the
    problems you can encounter so they are useless.

    This problem is related to a POST error code, so the technical
    background involved would make it very difficult to be covered on an
    end-user manual such as the one linked.

    I haven't had the chance to use any of these drivers because of the
    nature of the error on my laptop, which prevents it to boot and start
    the OS normally and I'm starting to think there are little chances to
    fix it up unfortunately.

    Thanks anyway for helping ;)
    beltrixx, May 4, 2010
  13. Some laptops will not POST without a CMOS battery; this not as common
    now as it used to be, but this is an older laptop.

    Check and see in the BIOS (if you can get into it) if the laptop is set
    to take some action ("resume") on power up OTHER THAN "boot".

    2 volts is a very low voltage for a lithium battery. I don't conclude
    that the existing CMOS battery is good.
    Barry Watzman, May 4, 2010
  14. beltrixx

    beltrixx Guest


    I know is a very low voltage but when the computer is powered through
    the AC adaptor, the Lithium battery voltage is about 3 V. It should
    power up, isn't it? there is no way to get into the BIOS although I
    have tried all possible key combinations (Fn+F1, Fn+F2, Fn+Esc, Ctr+Alt
    +Del, Ctr+Alt+F1 and so on) and the fact that neither the power button
    nor the sleep button is working makes me think of a motherboard

    Assuming you are right about the fact that this laptop maybe refusing
    to power up due to a defective CMOS battery, how long would it last a
    brand new replacement? I have read that VL3032 batteries can be
    recharged 1000 times aproximately and probably I cannot rely on the
    main battery of the laptop (Ni-Mh) due to its age, so it would become
    necessary to have the laptop always plugged using the AC Adaptor and
    this would imply using one recharge cycle of the Lithium battery every
    time the Ac adaptor is used.

    A workmate has been testing and recharging the batteries and these are
    the results :

    1) 7.2 V 60 mAh battery pack : can be charged but if the laptop is not
    plugged, charge is lost very fast.
    2) 3V VL3032 Lithium battery : is dead. Voltage is about 2 V (end of
    service life according to its leaflet) although it shows 3V if
    measured while connected to the mobo. My friend has not been able to
    charge it because this type of battery is not compatible with his

    I'll look if I can simulate #2 using two standard 1,5V rechargeable AA
    batteries for a while. The recharge current (from the board to the
    batteries) would be so low that it would make it impossible to damage
    the batteries but I first would need to check whether the current
    originated from the batteries would damage any chip on the mobo.

    In my opinion this laptop isn't well designed at all and is far from
    being flawless. The mere presence of three batteries inside it make it
    a matter of science fiction powering it up but this won't make me give
    up so fast, I need it to power it up and boot into the OS !

    Thanks everybody for your help ;)


    Manel (beltrixx).
    beltrixx, May 5, 2010
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