1. Visiting from the US? Why not try DIYnot.US instead? Click here to continue to DIYnot.US.
    Dismiss Notice

Makita Nail Gun GN900SE

Discussion in 'Tools and Materials' started by LePaul1, 23 Oct 2019.

  1. LePaul1

    LePaul1

    Joined:
    17 Feb 2014
    Messages:
    7
    Thanks Received:
    0
    Country:
    United Kingdom
    Hi - I have a Makita GN900SE gun. It is serviced regularly, by me, with oil, rings etc. Recently it started to run out of battery life quite quickly. So, I bought 2 new batteries. This didnt help as the new batteries ran out of power after 20-40 nails. So, I assumed it was the charger and replaced the charger. Still no improvement with batteries still dying after 20-40 nails.

    The only thing left it can be is the gun itself. Can anyone point me in a direction as I have not got a clue what this could be?

    many thanks in advance.
     
  2. Sponsored Links
  3. JobAndKnock

    JobAndKnock

    Joined:
    30 Sep 2011
    Messages:
    3,543
    Thanks Received:
    688
    Location:
    Lancashire
    Country:
    United Kingdom
    Possibly battery contact/terminal issues inside the gun? Passlode guns can exhibit rapid battery discharge when the battery terminals are coated with black oxide.
     
    • Thanks Thanks x 1
  4. LePaul1

    LePaul1

    Joined:
    17 Feb 2014
    Messages:
    7
    Thanks Received:
    0
    Country:
    United Kingdom
    Thanks JobAndKnock for the response. I will strip it this week and have a look inside it.
     
  5. lostinthelight

    lostinthelight

    Joined:
    11 Feb 2016
    Messages:
    1,539
    Thanks Received:
    268
    Location:
    monmouthshire
    Country:
    United Kingdom
    • Thanks Thanks x 1
  6. LePaul1

    LePaul1

    Joined:
    17 Feb 2014
    Messages:
    7
    Thanks Received:
    0
    Country:
    United Kingdom
    Thanks lostinthelight It seems this is out of stock atm but I get the idea.
     
  7. lostinthelight

    lostinthelight

    Joined:
    11 Feb 2016
    Messages:
    1,539
    Thanks Received:
    268
    Location:
    monmouthshire
    Country:
    United Kingdom
    Theres lots of them from different sellers on ebay
     
  8. LePaul1

    LePaul1

    Joined:
    17 Feb 2014
    Messages:
    7
    Thanks Received:
    0
    Country:
    United Kingdom
    Since I posted this I have tried the terminals and cleaned them. The batteries are charged to 8 volts, tested using multi-meter. The light on the gun will switch from flashing green to alternating green/red flashing and then to constant orange. It does this with all 4 new batteries. It will fire only 2-4 nails before this happens. Once this happens the multi-meter shows that the battery charge has dropped to 7.93 volts.

    I stripped the gun and inserted a battery and pressed the trigger. The ignition system gave a spark at each press.

    The only electrical components in the gun are the switch and the spark unit. I don't suspect the switch but could the spark unit be the problem?
     
  9. Sponsored Links
  10. JobAndKnock

    JobAndKnock

    Joined:
    30 Sep 2011
    Messages:
    3,543
    Thanks Received:
    688
    Location:
    Lancashire
    Country:
    United Kingdom
    Yes. I've had igniters fail in the past a couple of times, although when that happens the gun normally won't spark. Have you checked if the safety lock-out is working correctly?
     
  11. LePaul1

    LePaul1

    Joined:
    17 Feb 2014
    Messages:
    7
    Thanks Received:
    0
    Country:
    United Kingdom
    Thanks JobAndKnock If I am thinking of the same bar as you (the bar that is depressed with the contact top etc to allow the trigger to be fully depressed) then this is working fine. After a few nails the gun, when the light goes constant orange, the gun does everything as if it is going to fire but there is no power to the unit. The igniter doesnt produce a spark and the fan does not start up.

    There is, imho, an electrical problem. There are, of course, 3 main electrical components. The igniter, the switch and the motor.
     
  12. LePaul1

    LePaul1

    Joined:
    17 Feb 2014
    Messages:
    7
    Thanks Received:
    0
    Country:
    United Kingdom
    Ive just tried it again and when the gun has fired a nail the motor/fan runs as normal for a couple of seconds and then runs roughly, as if its running out of power
     
  13. JobAndKnock

    JobAndKnock

    Joined:
    30 Sep 2011
    Messages:
    3,543
    Thanks Received:
    688
    Location:
    Lancashire
    Country:
    United Kingdom
    In order to generate the sorts of voltage required to make the spark there must be some form of capacitor on the igniter board. Know any radio or TV repair folk who would be willing to check the igniter out?
     
  14. LePaul1

    LePaul1

    Joined:
    17 Feb 2014
    Messages:
    7
    Thanks Received:
    0
    Country:
    United Kingdom
    I've just been given a help desk number for Makita so I will give that a go this morning.
     
  15. motorbiking

    motorbiking

    Joined:
    31 May 2016
    Messages:
    4,263
    Thanks Received:
    478
    Country:
    United Kingdom
    sounds like a faulty discharge protection circuit. If you can find it, it can be bypassed with a bit of wire.
     
Sponsored Links
Loading...

Share This Page