AEG bluetooth active speaker fault

[Xenon-Codex]

AEG BSS 4812 only blinks its red light. No sound even from aux, and the bluetooth is not visible to cellphone. When I plug it to computer via USB, a microphone device appears. So the power supply seems to be working.
The board says CCY audio Monitor50i-M. I can't find any information.

[budm]

Re: AEG bluetooth active speaker fault

Please show us pictures of the top and bottom side of the boards. There may be many sub-power supplies, Voltage regulators, buck/boost converter... that will need to be checked.

[Xenon-Codex]

Re: AEG bluetooth active speaker fault

It seems to be a generic chinese board. First pic shows two missing capacitors, I removed those.

[Xenon-Codex]

Re: AEG bluetooth active speaker fault

If I heat the top left area within 1 inch of the corner, it starts to work. I tried with a piece of cardboard to prevent other areas to heat. The chip is a CD4052BM and the smaller one has no markings.

[stj]

Re: AEG bluetooth active speaker fault

4052 is an analog switch - probably for selecting the source.
some small caps in that area too.

i notice it has conductive/corrosive brown glue in places!

[Xenon-Codex]

Re: AEG bluetooth active speaker fault

How does that glue come off, with IPA?

[Xenon-Codex]

Re: AEG bluetooth active speaker fault

If I heat the corner too little, the light blinks barely visible until I press the button to change input. Then it blinks normally, i.e. the fault is on.

[Xenon-Codex]

Re: AEG bluetooth active speaker fault

The capacitor in the middle of the top edge was forgotten one, I changed it and so far the speakers have worked every time I switched them on.

[sam_sam_sam]

Re: AEG bluetooth active speaker fault

The capacitor in the middle of the top edge was forgotten one, I changed it and so far the speakers have worked every time I switched them on.

Good work figure out what was wrong with it

[Xenon-Codex]

Re: AEG bluetooth active speaker fault

This seems to be a common fault with this amplifier board/speaker model.