MagSafe power adapter slight flicker

In mid-september, an MBP A1286 would not start. It had flickering on the power connector occasionally; nothing on others.

Fiddling with the power adapterof my backup 8-year old MBP, I got better response from the light of the connector, but no love for the machine. [try working on 4GB of RAM, after the luxury of 16...]

About a month and a half later, I discovered a bulge in the power cord, near the transformer - right after the rubber connector. Uh-oh... In fact it won't power the old MBP...

Still... the old power adapter was generating new behaviour. Now the light would go orange. But no real love.

Today, an interesting snipped through google, pointed an accusatory finger at the battery. So, I disconnected the battery, plugged in my CCC drive. Nothing. But wait! light is orange, how can that be?

Unplugged everything, left battery disconnected, plug in disk, then power and it is logically 'green'. Power up button... Love (notwithstanding an abnormally long boot time)!

It seems a solution was found. But this is an appearance. Too many variables were at play and I am not convinced the issue was truly isolated.

a) Can I determine the battery is at fault?

b) Could anything in the circuitry be faulty? can this be checked?

c) the MagSafe adapter? should I try and splice open the cable to see if iCanFixIt ? (I resist Apple gouging)

d) the flicker. it is a signal. But how should I interpret it?

Further prodding has isolated some real issues. What follows is in case comeone stumbles onto the problem.

1) in this case, the adapter was the problem. It would short (possibly on cable movement) and kill the machine. Not re-startable.

2) the flicker is indicative of something wrong in the overall circuitry.

3) the get the machine to work again, I unplugged the disks (the optic drive is occupied by a second HDD) AND - notwithstanding Apple's printed instructions) the battery. I would leave the battery unplugged and boot without it, then plug the battery back into the motehrboard. The machine re-starts. Proven a few times.

Thus, somehow, the electrical circuitry remains charged somehow and does not allow to restarts with another adapter.