Reply To: BeoLab 8000: 5-pin cable from RCA-PCB to LED-PCB sensitive

[KolfMAKER]

Here’s another update. I made several other checks.

(Check 1) PCB 05 exchanged – I took the ‘PCB 05 Link shift board’ from another BeoLab 8000 and put it in the ‘trouble BeoLab 8000’.

(1) Result – Nothing changed. So, when nothing is connected to the RCA input on PCB 05: still a loud Hum. When an iPhone is connected to the RCA input, the hum is gone, Auto stand-by goes to OFF, but it also goes back ON again when I touch the 5-pin cable P4 on PCB 05.

So I conclude that the problem is not in PCB 05.

 

Observation: I noticed that when I touched the 3-pin JST cable from PCB 06 to the Amp, the Auto stand-by also switches to on. Same as when touching the 5-pin cable on P4 of PCB 05.

 

(Check 2) 3-pin JST cable changed – I hand-made another 3-pin JST cable to check if the original cable is the issue. This is to check if there is something wrong with the original cable between PCB 06 and the Amp.

(2) Result – When powering on, a slight hum/noise can be heard. Though it seems to be a higher pitch than before. Unfortunately, this hum/noise seems a bit to strong as the Auto stand-by does not switch OFF.

 

Observation: In the situation with the hand-made 3-pin JST cable, I noticed that when touching this cable or the 5-pin cable on P4 of PCB 05, nothing happens. Though, the BeoLab does not switch OFF.