Toshiba A300

[dmartins]

Hello guys ,

this A300 was delivered to me yesterday in this bad state, the computer restarts, the problem is due to the nec tokin I think, but here in nec tokin area we can see that it was shaved, which is what can be done here?
I already tested it with new tantalum capacitors and remains the same

Thanks in advance

[rievax_60]

Re: Toshiba A300

What is the ESR spec of those capacitors? Have you used the before to replace a NEC/Tokin capacitor?
Is the copper missing on the middle or just looks brown?

[inflex]

Re: Toshiba A300

That's quite badly damaged :-o

I'd consider replacing it with an array of 10 x 100uF 1206 ceramic capacitors. The effective resistance due to the solder joins and the mess in general is probably too high.

[rievax_60]

Re: Toshiba A300

There could be too much missing ground plane copper.

[dmartins]

Re: Toshiba A300

Yes , is the copper missing...

@rievax_60 , yes i already used this caps do replace a nec tokin ...

[rievax_60]

Re: Toshiba A300

It looks hopeless. You could try soldering short straight pieces of wire between the negative ends of the capacitors. Manly across areas of missing copper and trying to connect to anything that is ground plane. Some of the vias are not grounded, the ones with the extra space around them. Don't let them get shorted to ground.
Does it have the typical symptom where it tends to work better on battery power?

[highpulse]

Re: Toshiba A300

well its a simple fix . grab the upper part of the copper , get a unifilar wire , start joining all ground of does capacitors and finally solder the wire to the remaining copper on the uper capacitors.

therefor you must use osciloscope to see voltage ripple on CPU line to be sure you got a nice stable 1.05 volts line if its the case !