Vu+ UNO4K SE RAM MEMORY REMOVED

Discussion in 'VuPlus Uno Hardware troubles and Repair support.' started by Michal Matas, Jan 2, 2021.

  1. Michal Matas

    Michal Matas New Member

    Messages:
    8
    Likes Received:
    0
    Trophy Points:
    1
    Gender:
    Male
    Hello guys..I removed ram chip from uno 4kse ..because i was trying repair another receiver..with missing ram..and when i soldered original ram back..receiver not longer boot just blue dot in picture..Then i order new ram chip from ali express..soldered with hotair gun..and still receiver dead..any suggestion ? can be high temperature i soldered ram? or what i can measure now? thanks WhatsApp Image 2021-01-02 at 22.01.32 (1).jpeg WhatsApp Image 2021-01-02 at 22.01.32 (2).jpeg WhatsApp Image 2021-01-02 at 22.01.32 (3).jpeg WhatsApp Image 2021-01-02 at 22.01.32 (4).jpeg
     
  2. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

    Messages:
    2,452
    Likes Received:
    1,230
    Trophy Points:
    113
    Gender:
    Male
    Location:
    Netherlands
    Home Page:
    Yeah that is not a simple task to do...

    Placing/solder these balls chips are pretty difficult.
    When I place them it goes often not good because the solder balls are very small and could make easily create a short.

    I have only in most attempts lucky when the motherboard is good cleaned, absolute perfectly level in all direction, and absolutely very good aligned so that it's perfectly placed on the solder spots.

    I always use kapton tape to protect the surrounding area, and use a bga station with a correct profile to solder these on a motherboard.
    And even then, it could in some cases go wrong, often due the room temperature.

    In any case, it's important to not exceed the maximum temperature that is noticed often into the datasheet, in any case not to long, as also it's important to pre heat the motherboard before building slowly up the heat.
    To fast will often fail, the solder balls become often liquidate instead of sinking down as a sort of looking hamburger.
     
    raza05 and Aliraza63 like this.
  3. Michal Matas

    Michal Matas New Member

    Messages:
    8
    Likes Received:
    0
    Trophy Points:
    1
    Gender:
    Male
    thank you for nice answer .. i have scotle bga station..i preheat and use hot air gun on second attemp fix ram...but i make more heat and ram area warped damaged more .. so lesson learned on expensive receiver.
    will look for some mainbord for vu uno4k se.
     
  4. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

    Messages:
    2,452
    Likes Received:
    1,230
    Trophy Points:
    113
    Gender:
    Male
    Location:
    Netherlands
    Home Page:
    Pity to read but indeed, I basically have a sort of hate with these solder balls chips.
    It does not make it any easier to fix, and is more sensitive to malfunction than the older chips with legs.

    Best trick which is lately for me most of the time works, is to add some alignment pins to the chip, before removing , and use kapton tape to keep them on place, and at least on one side of the wide/length side.
    Than is the replacement of the new one a bit easier and has the chance of succeeding a better chance.

    Something like this....
    Untitled-1.jpg
     
    raza05 likes this.
  5. Michal Matas

    Michal Matas New Member

    Messages:
    8
    Likes Received:
    0
    Trophy Points:
    1
    Gender:
    Male
    ok.. i will use this suggestion next time... is there option ..skip this ram ..and just put some jumpers so receiver will work without this ram?
     
  6. Johnny B.

    Johnny B. Technical Support Staff Member Moderator

    Messages:
    2,452
    Likes Received:
    1,230
    Trophy Points:
    113
    Gender:
    Male
    Location:
    Netherlands
    Home Page:
    Not that I know, but my logic tells me it is not possible.

    With older type of memory with side pins, there were possibly some options, such as with thin wires, and with some modifications to use a laptop memory.
    But with this solder ball assembly it is difficult, if not impossible to do.
     
    raza05 likes this.