Thanks, R6 is a 15K resistor on this Cub, but it's one of those radial ceramic SBC type resistors. These seem a bit harder to get than usual resistors. Also the ones on the Cub PCB are 3-pin parts whereas the ones I see for sale are all 2-legged.
I did measure R6, powered off, and it read about 13.5K so it is probably just about still in spec, if in circuit unpowered resistance readings can be relied on, but may be failing. The 100uF capacitor shown in the diagram is probably the large C11 one I have already mentioned, which is the only electrolytic in the PSU area I haven't replaced, so it would be typical if that's the one that is on the blink. I'll have to look at getting an alternative for those as the new ones I bought aren't going to fit the board.
At the same time it's probably sensible to stock up on a few additional diode types as there are several in the PSU area which I don't have. I've only got IN-range resistors and there are numerous other types in the service manual parts listing.
I did measure R6, powered off, and it read about 13.5K so it is probably just about still in spec, if in circuit unpowered resistance readings can be relied on, but may be failing. The 100uF capacitor shown in the diagram is probably the large C11 one I have already mentioned, which is the only electrolytic in the PSU area I haven't replaced, so it would be typical if that's the one that is on the blink. I'll have to look at getting an alternative for those as the new ones I bought aren't going to fit the board.
At the same time it's probably sensible to stock up on a few additional diode types as there are several in the PSU area which I don't have. I've only got IN-range resistors and there are numerous other types in the service manual parts listing.
Statistics: Posted by BeebMaster — Fri Dec 27, 2024 12:03 pm