NEC TOKIN OE907 Problem: Toshiba Satellite L300 random shutdown when plugged in AC power.
This is my first post in Litlighter. I recently experienced some problems with my Toshiba Satellite L300 laptop which I bought about 4 years ago. The interesting thing is that I still use this Toshiba laptop as my primary computer, largely because of my emotional attachment to it. I typed and learned a lot from this Intel dual-core laptop that makes it still hard for me to part with it. A curious problem happened to it. The laptop began to freeze or giving blank screens or frequently shuts itself down in between some work. This random shutdown continued for sometime and gave me constant headache. Curiously, sometimes the laptop worked very well without any hitches. Soon I found that my Toshiba laptop works in battery without any problems but when I put the plug into the socket to charge it while laptop is running, all the afore mentioned problems occur. It either gets shutdown or freezes. So, I surmised there are some hardware problems with charging part of the computer.
I formatted the laptop to check if the problem happens due to some software error. I experienced this random shutdown/freezing of laptop in the newly installed Windows 7 and also in Ubuntu 12.04. I called Toshiba service center and they said this is a common problem with the Satellite series of Toshiba laptops produced during 2008-2009 period. As the one year Toshiba warranty is long over, they informed me that nearly 4500 Rupees will be needed to replace some faulty“chips”on the motherboard, though they did not specify the exact parts in need of replacement.
Dejected (because of expensive repairing option at Toshiba service center), I Googled the problem for long hours till found many similar problems reported from Toshiba Satellite owners. Later I also found that this random shut down also affected the Toshiba A200 series of laptops. The villain is NEC/TOKIN OE907chip-set. The picture of the same is shown below.
It is Tantalum capacitor. This capacitor is available for purchase from many Chinese manufactures from Alibaba.com. You can also purchase this either from Ebay or from Amazon. This is available in all these places. It is still expensive for me. A quick search showed me that NEC/TOKIN OE907 can be, very effectively, substituted by 4 numbers of 330uf 2.5 Tantalum SMD capacitor. These guides helped me (Techenclave, badcaps, ifixit, laptoprepairblog,tomshardware). It is very cheap also. A local search for 330uf 2.5 Tantalum capacitor brought no results and I had to buy 12 nos of 330uf 2.5 Tantalum SMD capacitor from Mumbai from Chip Components for 500 Rupees. Chip Components send me 12 nos of Tantalum Caps instead of 10 as I asked them to. the pictures of Tantalum caps is shown below.
There is one more reason why I went for Tantalum capacitors instead of NEC/TOKIN chip. NEC/TOKIN is a SMD (Surface Mount Device) about an inch width and inch in length. So, one needs SMD workstation to safely remove it from the laptop motherboard and then solider the new one in its place. SMD workstation is an expensive option, especially if you not taking it into a profession. I only to need to repair my laptop, so I went for cheapest option of Tantalum caps as this can be soldered into the motherboard with ordinary soldering irons.
I got the speed post after two days. Promptly I opened the laptop and with the tools borrowed from my friends.
Before tampering with the laptop, you need to know something...
The polarity of the Tantalum caps. It is absolutely necessary to understand which side is (-) polarity and which side is (+) polarity, without knowing this you will actually be doing harm to the laptop motherboard. Normally, that side of the capacitor which is marked with a silver line or some other similar lines represent (+) polarity. The picture taken from Wikipedia makes this clear
You need to have a star screwdriver to open Toshiba Satellite laptop. You can find innumerable videos in Youtube on how to open the Toshiba Satellite laptops. One word in caution is that no video explains how to remove the laptop keyboard and touch-pad socket. You can find a tiny liver like thing on the both end of the socket and it is detachable. Just pull out this liver ( normally black in colour) and the touch-pad and the keyboard cables will be loosened.
Buy or borrow a soldering iron, flux, led and a sucker( some call it blower also. The main purpose of this is to suck out the led melted by the soldering iron from the motherboard)
Absolute caution is necessary to get the NEC/TOKIN OE907 chip from the motherboard. You shall not break the circuits in the motherboard in anyway. There is a chance for this to happen if you use screwdriver to pull out the NEC/TOKIN OE907 from the motherboard. Scratches in the motherboard is not a problem but, the circut shall not come apart from the board.
The above two pictures are the motherboard pictures of Toshiba Satellite L300. The first is picture of the motherboard with keyboard removed. The second is the picture of motherboard only, without the laptop case, keyboard and even the cooling fan is removed. This is needed because the just below, on the other side of the motherboard, the processor is fitted. And, also to avoid damage to plastic parts, it is recommended to remove fragile parts off the board before soldering.
The two photos shown above display how the slot of NEC/TOKIN OE907 after its removal. I had to hard break it and NEC/TOKIN OE907 came off in parts. The first picture, out of the two above, shows how the board will look after the cleaning of the circuit track. You can use some screwdriver to leverage the chip while heating it with soldering iron. Also remember to apply ample amount of soldering flux on all sides of the NEC/TOKIN OE907 chip. The second picture out of the two above, shows how the slot of NEC/TOKIN OE907 will look like after you solder 4 nos of 330uf 2.5v Tantalum SMD caps into its place.
The address of Chip Components from Mumbai is given below, if someone from India wants to buy the same.
Shop NO:10, Old Hanuman Bldg,
Shamaro Vittal Marg, Off Lamington Road,
Mumbai, Maharashtra 400007
Many good things happened with the replacement of NEC/TOKIN chip. One is the disappearance annoying booting message “PM caps ......”
Actually I have been getting this message for quite long time whenever I boot into Linux, though this error message did not appear in Windows booting. Now I understand that PM caps means Power Manger capacitor, and in this case NEC/TOKIN. When I changed NEC/TOKIN with 300uf 2.5v Tantalum SMD Caps, this message simply disappeared.
The second good thing is that I cleaned the motherboard cooling fan. I saw a sponge like thing, which is about an inch in thick at the mouth of the fan. It was dust and dirt,accumulated there over a period of time and that actually blocked the airflow from the cooling fan. This resulted in incontrollable heating of the laptop as the airflow to cool the heating sink is now blocked. When I removed the dust pad from the mouth of the cooling fan, the heating sink began to cool down and the heating of the laptop is effectively done away with. Now my Toshiba Satellite L300 does not heat up. It is simply cool.
Average cost of repairing
Many shops will quote you different price for the parts. I first Googled about 300uf 2.5v Tantalum SMD Caps which led me Alibaba.com. They offer this caps and the cost of one dollar per piece, plus 8 dollar for shipping which will take at least two weeks for you to get the parts. Second, I searched for Chip Components and they offered the cheapest rate. One 300uf 2.5v Tantalum SMD Cap is only Rs 30 if you go to their shop in person. But to courier, they insist a minimum of 10 pieces. They ask Rs 500 for 10 pieces and this include speed courier chargers also. I got the courier on the second day of they sending it.
Many people helped me. My friend Krishnan gave me necessary screwdriver sets. I borrowed the soldering iron set from Sunil, The right substitute of 300uf 2.5v Tantalum SMD Cap was suggested by Nishant Pinto. And, also Chip Components who send me the necessary replacement parts!
I hope this guide will help you positively in repairing your laptop. Good luck!