A1990 20v/ 0.04-0.08a

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  • tomtom67
    Member
    • Mar 2021
    • 14
    • Germany
    #1

    A1990 20v/ 0.04-0.08a

    Hi,
    I got myself an A1990, 2018, board #820-01041A off of ebay (i know -.-).
    Seller mentioned liquid damage.
    First inspection showed only few (sugary) drops, but under the microscope I spotted some areas with degraded solder and smd contacts. I replaced around 10-12 etched caps and replaced solder in these areas.

    The board now switches to 20v, takes 40-80mA. I found no shorts on any power rail.

    I'm a complete n00b when it comes to those T2 machines - where should I look next?
    Are the A1990s even supposed to power up without battery? I've both yes and no answers, and the battery is pretty flat (7.6V), but won't charge either (I think it's failing too soon in the power sequence to enable charging).

    Any help out there?
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