All posts in those sections are pre-moderated because it is the only way we can keep the threads on-topic.
People should only reply if they can offer the service wanted or are interested in the service wanted, and this is stated in the sticky threads in the sections. However we get lots of replies discussing details of the fault and what the cause may be etc. By having full pre-moderation we can delete them without them appearing.
These are the sticky threads that nobody reads:
https://www.vintage-radio.net/forum/...d.php?t=101945
https://www.vintage-radio.net/forum/...d.php?t=101946
The software doesn't read or understand the posts, so it doesn't know the difference between "you have a PM" and "have you checked C17?". So either all replies or no replies are pre-moderated, and in those sections it's all replies.
If we didn't pre-moderate those sections the only other option would be to get rid of them, as allowing normal posting would cause us far too much work (we know from experience when they were created).