ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
In the schematics of the BeoLab 8000 in the service manual, the P4 connector for incoming audio is as follows:
I am connecting an external source to P4 and so far used pin 1, 2 and 3, with 3 as Gnd. But I get noise/hiss.
A friend looking over the electronic schematics with me, mentioned that I should use P4, pin 4 for Gnd. But if I look at the P4 connector physically on the amplifier PCB, I only see 3 pins in the connector, numbered 1, 2 and 3.
So where is P4, pin 4? (Physically on the PCB)
"You think we can slap some oak on this thing?"
Hi,
P4 is a 5 pin (pole) plug that connects the selector switch on PCB 5 (Line/Shift - the pice that has the RCA jack( to P5 on PCB 6 - Standby. From there, P6 (3 pin) and P7 (4 pin) connect to the power supply PCB PCB2 at P3 (4 pin) and P4 (3 pin) - these are the L/R/G audio signals).
Getting the audio to P4 on PCB2 is one thing, getting the remaining power on trigger/standby is another thing. The service manual schematic is a little tricky to figure out.
I have always used all of the original stock parts to test/repair, so that means the main module and the 3 separate pieces for the power/powerlink, RCA, and the standby led.
Good luck,
Bill
Here's a picture.
From left to right:
You’re confusing the amplifier board (PCB2) with the small pcb (PCB5) at the bottom which holds the switch and RCA socket.
Thanks BeoBuddy.
I am aware that the picture of the electronics schematics I added, is confusing. The red rectangular that is used to mark the pins of P4, is located in the PCB5 & PCB6 section.
Nevertheless, the connecting lines of P4-1 till P4-4 go all the way down to PCB 2/the amplifier.
So if you look at it that way, I still wonder where (physically seen) pin 4 of P4 is on PCB2/the amplifier. Do you know?
The numbering of the jack/plug sets changes on each PCB. In your photo, P4 is a 3 pin set on PCB2 that connects to P6 on PCB6 (were the standby indicator LED is located). P3 in your photo in a 4 pin jack on PCB2 that is connected to P7 on PCB6.
To get everything working on an original unmodified BL8000 you need the 3 separate modules PCB 5 (where the RCA jack is), PCB 6 (standby), and PCB 7 (where the power link is) to connect everything properly to PCB 2 (power supply, crossover, and main amp module).
The jack/plug sets on one PCB in the chain will be numbered differently from the set that the wire connector used will later connect to on the next PCB in the chain.