1. BBC Model B+ 64K.
2. Continuous beep, black / blank screen on power up.
3. Removal of all ROMs except OS / BASIC. Then a sequential piggy backing of a known good 4164 RAM chip at each of the eight RAM positions on the motherboard starting at IC55, then IC56, 60, 61, 64, 65, 66, 67 etc.
Procedure identified IC64 as bad as the machine booted when the 4164 was put on top of this chip as shown below.
4. I initially tried removing all ROMs and cleaning legs / pins. I then checked the links to make sure all were present. This procedure will work for one bad chip, however I doubt if it would work for multiple RAM chips that might also be faulty. As the B+ motherboard has no link S25, it's difficult to use the 'switch bank' technique to identify if the problem is in the first or second bank of RAM, unless one of you knows a similar feature that can be used on the B+ range?
Hope this helps.