Talk:BBC Micro Model A/B Capacitor Replacement Guide

C9 Main Board Capacitor

Can I double check the C9 value on this list? I have an Issue 4 BBC Model B. C9 on the board looks like a 10uF.

When I look at Power supply C9 looks like the 220uF?

Because I have a low -5V (I am measuring -4.37V) I am assuming that this is linked to my current problems. Boots and runs normally from cold for 5 minutes than crashes. Fails to restart until completely cold (or capacitors discharged???)

I dont have much experience in all of this so any clarifaction welcomed.

By the way great article.... thanks Mike 2A01:CB00:8118:5500:E84E:45F0:E1A4:C4B 09:36, 13 December 2025 (GMT)

Hi Mike,

Very good catch! I've just checked my issue 4 board and it's the same! I will update this now.

All the best,

Josh Josh (talk) 23:57, 14 December 2025 (GMT)