Toshiba laptop only will turn on at times 1

[electronicsfreak]

I am working on a friend's laptop that she was having trouble with. I agreed as it was out of warranty as I normally do not like taking laptops apart. It refused to turn on at first no matter what I did. So I took it apart, tested the power lead and wires into the motherboard and all were fine. Tested the laptop with two different power adapters as well. Both adapters work fine, but the laptop would not turn on. Could not figure anything out so I put it back together, and then it started working for a short bit. Got it to turn on, lasted long enough to see this error "rtc battery is low" and then made it into the bios. Then it shut off.

My next thought was maybe the bios battery is bad, so I replaced it, and still same problem. I would flash the bios to a newer version if it would stay on more than 5 seconds. When it stops working, you will not see any display lights or anything. It acts as if there is no battery or power supply to it. Then sometimes you can get it to show again. Strangest thing I have seen on a laptop.

Anyone ever experience this or have any idea about this?

There is a point in wisdom and knowledge that when you reach it, you exceed what is considered possible - Jason Schoon

 

[rclarke250]

What is the model number? Also, does the laptop start up under battery power? There is a known issue with some of the laptops, if it has a NEC tokin oe128, or oe960. It is normally found on the opposite side of the board that has the cpu, inside the cpu support bracket.

Here is a copy from an earlier post I made:

Just ran across this issue, if anyone hasn't seen it before, there is a super cap that goes bad. It is an NEC tokin oe128. Also been known to fail in other models, and maybe an OE096. the oe128 is 1200uF 2.5v cap, and the oe096 is a 900uF at 2.5v. I replaced it with 4 330uF tantalum caps. used the instructions found at badcaps.net, and just wanted to mention it works like a champ.

Symptom is the unit will run from the battery, and can charge from the ac adapter, but won't boot from ac adapter, and unit freezes as soon as it's plugged in. The super cap, has to do with changing the power profiles of the cpu, when it goes bad, too much ripple is seen on the filtered voltage, and it causes the cpu to hang.

Here is a pretty good ebay auction that has the caps to use. also nice pics and explanation of issue. Link

 

[electronicsfreak]

Will not start with either unless it decides to work. Then it only works for about 5-10 seconds, just long enough to get into bios. Then goes poof.

The model number is

Toshiba Satellite C875D-S7105

Part number PSCBGU-001009

There is a point in wisdom and knowledge that when you reach it, you exceed what is considered possible - Jason Schoon

 

[rclarke250]

Same model as my wife's. pull the drives out, if it still acts up, it is most likely a bad motherboard.

 

[electronicsfreak]

Yeah I am thinking it's bad as well. Going to check with her and see if she is okay with baking it as there is nothing left to do.

There is a point in wisdom and knowledge that when you reach it, you exceed what is considered possible - Jason Schoon

 

[cdogg]

Not trying to point out the obvious as you probably already tried this, but I have to ask...

Did you try pulling the battery and ONLY running off the power adapter?



-Carl
"The glass is neither half-full nor half-empty: it's twice as big as it needs to be."

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[electronicsfreak]

Yep, tried that as well lol. Also tried running it with hard drive yanked as well.

There is a point in wisdom and knowledge that when you reach it, you exceed what is considered possible - Jason Schoon