Toshiba Satelite A 205 works well on battery only but not okay with battery and

STechCo

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Hello,

Is there a way of fixing any specific part of the motherboard to avert this problem, since no bios or other software reconfiguration approach works with the laptop I have here. Please, help me out.

Thanks.
 

STechCo

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Specifically, the whole system freezes when powered on with ac adapter inserted but it works with just the battery. And thus I get to only use the laptop after the battery has been charged with the very same adapter but with the system off. Please, help.
 

RetiredChief

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My first quess would be that the AC adaptor is starting to fail. It appears that when just charging the battery the output is high enought to charge it. However when you try to power the laptop the current requirement is higher and the output of the ac adaptor is dropping off.

1) The easyist with a know good adaptor. Any 19V/4 Amp AC Adaptor with the same plug should work.

2) the adaptor can be checked, but requires the use of a voltmeter (DVM).
Cost is about 15->20 Dollars (@ walmart) and they are easy to use (Just google how to use a voltmeter.). They are VERY handy around the House and for Autos - Not just for "computers"

steps.
This first step requires caution. Obtain two straight pins. There are two wires that go to the plug, you want to stick one pin in one of the wires and about a 1/4 in away stick the other pin. The Caution - do NOT stick pin in so that it shorts out the two wires. Reason for this is that you want to measure the voltage under load, which means plugging the connector into the laptop.
Next step is to measure the unloaded voltage by puting one meter lead to the barrel and the other lead to the inside hole. Plug adaptor into AC. Output DC should be above 19 Volts. Note if you read a neg voltage, reverse the meter leads. If you read zero volt, one of the two pins is shorting both wires unplug and redo.

Next, plug adaptor into laptop (laptop OFF). remeasure the voltage, should see a slight drop. Then power on the laptop, the voltage will probably drop slightly more than with the when just charging the battery. If voltage drops significantly - Ditch the adaptor and buy a new one.

AS I said, for most, it easier to just try a known good adaptor.
 

STechCo

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Thank you. I have tried with four Toshiba AC adapters in our workshop, and the laptop still doesn't power on when current is running through the A/C to the board. I have contacted colleagues in other workshops and they believe the case is generic with Toshiba Satellite computers, yet don't know exactly how to avert the problem. One mentioned NEC/TOK OE128. As an electrical engineering novice, the testing, removals and installations of electrical components in relation to computers and accessories are done by our professionals. Beside my field of expertise, I contribute by way of research to all other departments. I will keep your advice to practice troubleshooting with voltmeters. But, I believe the solution is different. Please help if you can. Any other suggestions? Thanks. Peace!
 

RetiredChief

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I'm reminded of an old saying - BAD advice is worst than no advice.
With that in mind, I do not have the schematic of the input circuitry so it is very difficualt to provide advice. Myself, I'd probably dissasemble and using a voltmeter (and ohmmeter) start tracing the input voltage path from the input power connector to see if I could find a defective diode/resistor. A capacitor that has a high leakage current could also cause a problem. The capacitor would be an electrolytic and would show budging and or leaking around it.
 

sanjin_05

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Hi there, i got exactly the same problem. Notebook would work with the battery but not with ac adapter plugged in. I got the same notebook Toshiba Satelite A 205. Please if you 'll be so kind to tell me what went wrong ?
best regards, Sanjin
 

pallidin

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I have an older model Toshiba (sat 4200 series). same problem.
power cord charges battery, but unit only runs from battery. take battery out (power cord still plugged in) unit will not turn on. the little light still acknowledges the power cord, but wont activate. I've heard of a number of possibilities:
blown fuse on moth.brd, bad power cord, planets in wrong allignment... also heard of removing power programs and re-installing. havent tried that one yet.

my next step is to try stripping laptop to bare-bones and checking fuse. from there, we'll see!
 

countrywill

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countrywill

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Hi the problem here with your laptop only working on battery and not on power supply is quite simple. On the motherboard there is a NEC/Tokin capacitor under the processor this is what is causing the problem it needs to taken out and replaced with 4 SMD 2.5v 330uf capacitors available from ebay. I have already done 3 of these all with the same problem
Hope this helps
 

Billc9999

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