The Toshiba A300 PSAGCE If Battery Powered Operating Normally. With Power Supply And Battery By Strange Errors With The Hard Disk Or Does Not Start.
The Component NEC / TOKIN 0E907 Must Be Replaced
The solution involves the replacement of this component with an identical or with 4 capacitors Tantalum capacity 330UF 2.5ve SMD format similar to this photo, which you can find in specialty stores or on the internet:
In some repairs I also used 2 330 and 2 220 (derived from the motherboards of results) and in any case I was successful.
The strange thing is that this PC starts to show signs of imbalance very different such as the inability to boot fully when powered with the power supply, while a battery sometimes works regularly. This maybe because the battery PC running at reduced power so that the capacitor NEC TOKIN is malfunctioning affects less.
Fueling with the power supply – also disconnect the battery – strange things happen: PC often does not turn on its own (even the logo of Toshiba bios) or starts but freezes in mid-boot, bringing disk errors: which is not true because if we do that then starting battery is operating normally.
Or, testing the disk on another PC, you may notice that error has no bad sectors (HD Tune Pro).
So in most cases the only culprit is that NEC TOKIN.
Sometimes the problems are reduced by disabling some BIOS settings and go by the processor to the middle of his power. Even for a test, enter the BIOS by pressing F2 at startup. Then septate these parameters:
– In Advanced ->
Voice Core Multi-Processing Enabled =
Voice Dynamic CPU Frequency Mode = Always Low
Now we illustrate how Cmq usually act on this model for a repair FINAL.
This is the exact model that I have repaired, but this repair is common to other Toshiba models, that is, those who have problems with power on / off and fitted with the NEC / TOKIN 0E907 .
We begin to disassemble the PC. Svitiamo all the screws and parts on the floor below.
Detach the plastic batten above the keyboard, svitiamo the 2 screws, dismantle the keyboard.
Now detach all the straps, cables and screws on the upper floor.
Now detach the upper part of the body.
And here we are finally to the motherboard … but it is not over. We have to unplug everything.
Already you can see the aluminum plate that hides under the faulty component.
Detach all monitor cables, additional screws and extract the motherboard.
Now svitiamo the three screws that hold the aluminum plate and we find ourselves in front of the NEC to remove.
This second component of news taken from the internet is a capacitor 1200UF also available with initials 0E128.
The idea is then to replace it with four capacitors at least 300.
The most unpleasant is now unplug this component. Personally took me a long time. I used flux and hot air station but it was hard because of the position is not very happy.
In the end this is the result, after a good cleaning.
Now we have to solder the 4 capacitors. We need to weld the head with positive + outwards, taking into account that the two inner strips on the plate only the negative and the positive side ones.
The result should be similar to the following.
Personally I have not been so ordained in welding but the important thing is the outcome … so I installed the power button and without closing the pc I did some tests ignition.
Lights up !!!!
Now we perfect the work. In the photo below – relates to one of the first repairs made long ago, if you notice I cut the frame as I had welded the capacitors in a disorderly fashion.
Subsequently however, not only are able to weld them in a clean and orderly – without any cutting of the metal adapter – but then I proceeded to also enter the thermally conductive pad of half a millimeter between the capacitors and the metal foil, so as to dissipate the heat : this is something VERY IMPORTANT because these capacitors are usually not made to withstand high heat and with time become detached or break.
So remember the thermal conductive pad !!! Even if it costs a fortune is key !!
Inserting obviously do a little thick, is not a problem because the metal sheet is thin and you can bend it slowly and secure it with the three small screws; but the important thing is that the chip on the right side also grip on the metal plate (this component takes normal thermal grease).