PB2400c can't start

[Azamat Farrakhov]

Hi, list

Can anyone help to diagnosing my PB2400c by following
 symptoms, and maybe to eliminate problems:

(this PB2400c bought on eBay, where seller describe that
 can't run this machine, but  startup sound present. PB have no
 upgrades, except RAM (180 MHz, 1,2 Gb HDD, 16+64 MB
 added))

1) I found totaly breaken ferrite filter around trackpad train
 (where train connected to the Logic Board) inside laptop

2) general condition of laptop:

Startup Sound present when:

a) every second time Reset Button pushed and dismissed
 (another time powerbook turn to "power off" state)

b) by pressing CTRL + Command + Delete buttons

c) by pressing On/Off button (if PB in "Power off" state)

after hearing Startup Sound do nothing (HDD not start,
 screen is black)

3) resetting PRAM (by holding Reset button and by
 pressing Command + Optition + P + R after Startup
 Sound ) in general not help to run laptop

4) If try to reset PRAM many times, or if do not try to
 run laptop big time interval, Mac OS may successfuly
 loads. But sometimes only HDD start to spin after
 Startup Sound and Mac OS not loads.

5) When Mac OS loaded, I can work with laptop
 (run software, etc.,) but very small time, from 1 minute
 to 20 minutes. Then everything stop (freeze). If to restart
 laptop without time delay (1 - 3 seconds after freezing)
 OS may load again 50/50.

Thanks for attention, Azamat