I have an old rev.2 (I think) model B. It already has the 000 Fuses, but still only 256 MB of RAM. I wanted to use it for some small projects, but it does not run very stable. I tested TP1 and TP2 and measured only about 4V. This is obviously too low.
I was using different power supplies: Apple 5W and 12W adapters, a 1.5A adapter I am using with my RasPi2 and also tried powering via my MacBook Pro's USB port. All the same, I always get around 4V.
Could it be some component on the RasPi board? Can I fix this?
I have attached a picture of the RasPi in question to aid the discussion.