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

#10047
KolfMAKER
BRONZE Member
  • The Netherlands
  • Topics Started 15
  • Total Posts 106

Findings

First I disconnected and took PCB05 and PCB06 out of the speaker. Checked again for foam rot rests. Did some extra cleaning to be sure. Then I made following checks and did resoldering.

Schermafbeelding 2022-10-22 om 17.09.34

Checks
PCB 05 – Link shift (in outside foot)

  • Continuity: measured continuity on all traces and solder points connected > OK.
  • Re-soldering: re-soldered all solder points, incl. connectors and component pins > Done.

PCB 06 – Stand-by (in bottom speaker casing)

  • Continuity: measured continuity on all traces and solder points connected > OK
  • Re-soldering: re-soldered all solder points, incl. connectors and component pins > Done.

P4 Connector (between PCB05 & PCB06)

  • Continuity: measured continuity on all 5 pins of the cable > OK.

 

Next

After this I put the BeoLab back in original configuration: PCB06 screwed back in normal position, PCB05 connected but hanging loose. iPhone connected (as audio source) via external mini-jack to RCA cable, connected to RCA in foot. Result: There is a little hum, but Auto stand-by does switch OFF.

Findings:

  • When the P3 connector or cable is touched, Auto stand-by switches ON. But when let loose, it also quickly switches OFF.
  • When the P4 cable is touched, nothing happens.
  • When the P6 connector (audio cable) on PCB05 (Link shift) is touched, Auto stand-by also switches to ON. But also, quickly switches OFF when let go. This also happens when the connector of this same cable on the amplifier side is being touched.

 

Question

There still is sensitivity in the audio signal path.
What is the best next step I could make?