Toshiba A205-s5803 Freezes when AC plug is inserted.

[rclarke250]

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.

 

[goombawaho]

Interesting. Wonder how many of those models affected got thrown out vs. fixed. I probably would have diagnosed "bad motherboard". Most people aren't going to do soldering on their mobo and a tech is going to bill you $75 to $125 to fix it. At that point you start thinking - repair vs. replace.

 

[rclarke250]

Didn't even have to take it that far apart, on this model, the bad part is located under the keyboard, right inside the cpu cooler bracket. Took less than an hour to fix, parts taken from an old compaq board, it will make a nice gift for my niece. Bought the laptop off ebay for 100.00. doubled the ram with extra memory laying in a drawer, update to windows 7 pro I had an extra of, and she should be happy.

 

[goombawaho]

Aren't you just a "mister fix-it" on the cheap, even. Good deal.

 

[eddysan]

Seems to be something wrong with the stepdown chip... What happened without battery and only ac adapter?

 

[rclarke250]

No boot.

 

[rclarke250]

Also, this wasn't a question, this topic was information, on what the symptom was, and what I did to fix the issue. It was a bad capacitor.

 

[eddysan]

Sorry, I didn't read properly... My fault, thanks for the tip!