Is it really the NEC/Tokin ?

[pecrie]

So , I have this Toshiba A300 - 10S - 15" screen.
With T3200 / ATI Radeon GPU on separate small board.And the screen stays black.

On power start all the leds are burning - sometimes it will reboot after 1 or 2 seconds.It sometimes reboots 3x in a sequence.

I have watched the video about replacing the NEC/Tokin cap.But I also did measure the voltage on the cap.It is around 0.9 Volts DC.

To me it looks good - or is the Tokin cap still not really good ??I will try to measure the ripple on the Tokin cap

I did a search on this forum and I have read many posts about this topic - but I hate to replace a cap that may be still good ....

Any thoughts ...

[ktmmotocross]

Re: Is it really the NEC/Tokin ?

replacing that cap is still good, because of their failing. u cannot measure ripple without osciloscope

[piernov]

Re: Is it really the NEC/Tokin ?

It is very often the issue but when it fails it's usually not so sudden. It will start to be unstable on AC power and refuses to boot. Usually it works better on battery only.
No harm in replacing it if you have good candidate for replacement capacitors, as it will most likely fail one day anyway.

[ala_borbe]

Re: Is it really the NEC/Tokin ?

heat nec/tokin cap with heat gun
turn it on and wait
after few reboots it should turn on
replace cap

[ontikka]

Re: Is it really the NEC/Tokin ?

Replace NEC/TOKIN with 4 capacitors : 330μF / 2.5V
This video explains how to install it :
https://www.youtube.com/watch?v=Rg5QLlUs_0M

[pecrie]

Re: Is it really the NEC/Tokin ?

Maybe my first post was not really clear.The laptop is starting but with all the leds on.
The fan is spinning but all the time I have a black screen.

I believe that I could switch off with the power button.So the screen is black all the time.Now I have programmed the bios chip with a bin file I found on internet.

But it is not the same as the bin in the bios chip.Anyway I did the re-flash , but now the laptop will not turn on .... ??
I will put the Original bin file back and see what happens ....

[pecrie]

Re: Is it really the NEC/Tokin ?

Ooo my mistake ... (((
It seems that I have also desoldered a resistor which was between pin 1 and 3 of the bios chip ...

I took it of the board and then I lost it - cannot be found (it is such a tiny thing)
That's why I did not notice it -

So will try to find the value and put another in place

I will the new bin file in the chip and see what happens ..

[ktmmotocross]

Re: Is it really the NEC/Tokin ?

why dont u ask for brd or schem here?
why u spam with another thread in bad section?

damn put yourself together dude