Assuming you're discovering and replacing one faulty component at a
time, a pack of 4 fuses will allow you to replace as many as sigma 4 (10)
components in total before you run out of fuses. If you carry on the
procedure using another pack of fuses, you could land up replacing
components a total of 36 times (8+7+6+5+4+3+2+1).

I think your good fortune is that they *only* come in packs of four. I
can't see you investing in yet another pack to continue your "Suck it and
see" approach to repair by component substitution unless you really do
have nothing better to do with your spare time.

If you've seen any of my previous follow ups, you'll know exactly where
I'm coming from on this. :-)

I agree with you but I have to work within my limitations so the fuse
and diodes are about the extent of it then it will head to the bin. It
is too late in life to start learning the `trade` so I have to follow as
best I can the advice given. Mechanical is my thing mostly, like just
started watch repairing which wont be a problem for me as I can
physically see whats wrong, unlike electronics.
DIY I will always give something a go before binning.(with safety in mind)