88000 battery box problem

[DzieX]

Hi, it seems my battery box doesn't work (with fresh batteries). Has anyone tried to fix it?

Edited September 1, 2024 by DzieX

[JopieK]

Do you have a multi-meter? You could than check the voltage of the cells and the combined cells. It should be around 9V (6x 1.5V).

Apart from that, it seems to be a very straight forward PCB. There is probably a reverse polarity protection chip under the black gloop. The other (SOT-23-5 or something alike) seems to be an overvoltage protection (I can't read the numbers but something like: https://nl.mouser.com/datasheet/2/294/r1524_ec-3133291.pdf)

You could check the leads of the LDO (is the input voltage correct, is the enabled pin working, what is the output if anything).

There is also an alternative part number: 64228, see also: https://www.philohome.com/batteries/bat.htm

 

[DzieX]

 

1 hour ago, JopieK said:

Do you have a multi-meter?

I have. It seems that it's mechanical issue - 9V doesn't even reach PCB. I connected 9V from lab power supply and it seems to work. It seems (-) spring is not well connected to the frame.

[JopieK]

Aha, great that you found the culprit. Well there are a lot of AAA battery boxes (non-LEGO I mean), maybe you can obtain a part from it to fix it.

[djm]

Perhaps this is a variation of this ?

 

Edited September 2, 2024 by djm

[DzieX]

16 hours ago, JopieK said:

Well there are a lot of AAA battery boxes (non-LEGO I mean), maybe you can obtain a part from it to fix it.

Thought about it. I'll update this topis when the fix is ready.

[JopieK]

18 hours ago, djm said:

Perhaps this is a variation of this ?

Good thinking. If we just had those pictures from a decade ago...

[DzieX]

Was able to fix it with glue and paper :D I'm not very proud of it, but works :)