Having determined the Microcomputer PCB (Module 09) has a problem in this Beomaster 8000 receiver, I removed it to examine it more closely.
I am not fond of these Microcomputer (uC) PCB modules from the early serial number Beomaster 8000 units.
B&O decided to solder the top and bottom (metal) lids of the uC assembly to the PCB. On later serial numbers, B&O changed the PCB shielding to be a metal frame around the PCB with snap-on lids.
To remove the metal lids on this uC PCB, the board connections have to be de-soldered.
It is safest here to use solder wick on the six mounting spots.
Here is the 09 PCB with the metal lids removed.
Right away I could see some breaks in the 09 PCB traces near connectors P75 and P76.
I verified the open trace connections with my DMM then set about repairing them.
Of course I hoped this would be the single source of the 09 Module problems and could move forward.
Here is the PCB 09 with the breaks in the traces bridged. On the wider traces I decided to use some copper strips. On the two thin traces I just used some signal wire.
Note that while I had the 09 PCB on the soldering station, I reflowed the solder joints on all of the 09 PCB connectors.
I tested the connections again with my DMM, then re-installed the 09 PCB in the Beomaster to try powering it on again.
This time I do get the Standby LED with this original 09 PCB.
The control panel buttons do not consistently operate the Beomaster 8000 though.
I double-checked source selection, volume control and FM tuning using a Beomaster 8000 remote control.
That worked so there is an issue with the control panel buttons connected to this original 09 PCB.
With the remote control though, I checked out some of the Beomaster 8000 functions.
I could select all of the sources but the FM tuning did not work. The lack of FM tuning was a reason the owner sent me the Beomaster 8000 so at least the reason for that problem makes sense.
This picture shows the selection of FM presets P1 and P8. You can see that the FM tuning indicator is not correct. The tuning control couldn't do anything that made sense on the display either.
This photo shows source selections for phono and tape 1. I also checked tape 2. Those all select fine except that I had to do the selections from the remote control.
My next test was to uninstall this original 09 PCB and replace it with one of my Workshop Beomaster 8000 09 PCB modules again. This time, however, I grabbed my Workshop 09 PCB from an early serial number Beomaster 8000. That is a better match than the late serial number 09 PCB I tested with earlier.
Here is my Workshop 09 PCB next to the fault 09 PCB from this Beomaster unit.
They look identical except that my Workshop 09 PCB has a new 22uF capacitor and 1uF capacitor.
It also has new oscillators.
With my Workshop 09 PCB installed, the Beomaster 8000 source selections, volume adjustment, balance adjustment and FM tuning all work. Both from the control panel and the remote control.
I can see that a separate issue with this Beomaster 8000 is on the display segments.
The FM tuning display is missing one segment and the period for the frequency display.
What I have to do next is figure out what the solution will be for this Beomaster 8000 unit.
This project has budget and time constraints that limit my choices.
That leads me to wanting to just replace the original 09 PCB with my, already restored and working, Workshop 09 PCB.
The time it would take to troubleshoot and rework the broken 09 PCB could be expensive and at the end, it would still be a PCB that had repairs to some broken traces. I could live with that if this were my own Beomaster 8000 but not when it is a unit that has to be shipped back to an owner.
Another option would be to assemble a new 09 PCB from scratch using a new PCB from Fredrick Adenholm. He has reproduced the Beomaster 8000 Output Amplifier PCB, Display PCB and uC PCB.
The FM tuning display is missing one segment and the period for the frequency display.
What I have to do next is figure out what the solution will be for this Beomaster 8000 unit.
This project has budget and time constraints that limit my choices.
That leads me to wanting to just replace the original 09 PCB with my, already restored and working, Workshop 09 PCB.
The time it would take to troubleshoot and rework the broken 09 PCB could be expensive and at the end, it would still be a PCB that had repairs to some broken traces. I could live with that if this were my own Beomaster 8000 but not when it is a unit that has to be shipped back to an owner.
Another option would be to assemble a new 09 PCB from scratch using a new PCB from Fredrick Adenholm. He has reproduced the Beomaster 8000 Output Amplifier PCB, Display PCB and uC PCB.
I have all three of those blank, ready to populate boards. The 09 PCB is pictured above.
However, in the case of this project, doing that to replace the 09 PCB is out of scope.
