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Activity Forums ARRI ARRI Alexa SXT W not booting unless on external power.

  • ARRI Alexa SXT W not booting unless on external power.

    Posted by Amer Hanna on September 2, 2020 at 8:45 am

    Last year (~ Feb-March 2019) our customer bought two ARRI Alexa SXT W but did not start working on them right away.

    Problem Description:

    • In February 2020, the customer tried to start the second camera (the first one worked without problems) but he was not able to get it to boot on the onboard battery.
    • When the camera is connected with the BAB-V backplate (K2.72010.0) it cannot boot on the onboard battery. They have to connect it using the 2-pin BAT power cable for it to boot. Then, they can disconnect the 2-pin cable and continue working on the V-Mount battery.
    • After “jump-starting” the camera, They can turn it off and on and replace the onboard battery without problems, and it still boots and works normally. However, if they turn the camera off for more than 3-4 hours it would not boot anymore until they “jump-start” it again using the 2-pin connector.

    Tried Solutions:

    • We tried changing the battery and the same thing happened. Also, the battery is able to power the other camera.
    • We tried leaving the battery on the v-mount overnight and it started without problems the next day. But when we removed the battery for ~5 hours it didn’t start anymore until we plugged the external battery.
    • We were advised of the presence of a configuration setting (on older Alexa models) that permitted the camera to use the onboard battery only or the external battery only or both. We were not able to find that configuration setting.

    Thoughts on solutions:

    Is there an internal battery (similar to bios battery on computers) that may be empty? I’ve noticed that the internal time code starts from zero when we jump-start the camera using the external battery and it does not reset even if I turn off the camera and disconnect all batteries for a short period of time.

    We tried to reach ARRI but all they said that we should send the camera over, but this is difficult since the closest ARRI service center is in another country and shipping is very hard these days (Corona Virus).
    I want to explore all basic solutions before sending the camera on a 2500 km trip.

    Gary Adcock replied 3 years, 10 months ago 2 Members · 1 Reply
  • 1 Reply
  • Gary Adcock

    September 2, 2020 at 2:08 pm

    Since the Battery plate was not made by Arri, I would swap that out first.

    Sounds as if there is a short in the plate or if it had a fuse, the fuse has blown.

    It is a simple 5 minute procedure if you have an additional plate lying around, Arri made that camera extremely easy to service and that is one of the user defined service repairs.

    (I am not an official Alexa Tech, but I could be)

    Gary Adcock
    Workflows and Wisdom during Covid.

    Chicago, USA

    gary adcock

    Post and Production Workflow Consultant
    Production and Post Stereographer
    Chicago, IL

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