How could wrong Amperage affect a laptop

**sharder8** · April 5th, 2011, 02:52 AM

Originally Posted by ToshibaL305D

My laptop requires 19V/4.74A and I needed a 3-prong adapter because the default one had only 2. I researched the right replacement part for that adapter and found an adapter with the same code on Amazon. The new adapter I bought was giving the following output: 19V/6.5A.
My laptop died yesterday after 11 days of using the new adapter. Been using my laptop for 2 years before that. The last posts here are contradicting each other. I am not sure what happened... but it will cost me a lot more to repair it. Does anyone have an explanation for this?

If it was one of the cheaper Toshiba's, I'm not surprised it died a little over 2 years old.

I work on/repair 1 -2 Toshiba's a week and the quality isn't there in the cheaper ones. (Same with all the different brands.) The Toshiba A/C plug has gone to a adapter connected to the the MoBo via wires with a disconnect. Some that I've worked on used 2 thick wires, some 4 thin wires, both seem to have problems/weakness'.

Long story short . . . Your laptop may not be dead. You need to find out 2 things -- a) is the A/C adapter good or not, and b) is the A/C connector okay inside the laptop.

Harder

**ToshibaL305D** · April 5th, 2011, 10:49 AM

Originally Posted by sharder8

If it was one of the cheaper Toshiba's, I'm not surprised it died a little over 2 years old.

I work on/repair 1 -2 Toshiba's a week and the quality isn't there in the cheaper ones. (Same with all the different brands.) The Toshiba A/C plug has gone to a adapter connected to the the MoBo via wires with a disconnect. Some that I've worked on used 2 thick wires, some 4 thin wires, both seem to have problems/weakness'.

Long story short . . . Your laptop may not be dead. You need to find out 2 things -- a) is the A/C adapter good or not, and b) is the A/C connector okay inside the laptop.

Harder

Let me just correct what I said. The laptop is not entirely dead. I can power it on but the screen stays off. The cooler is spinning, dvd drive is working, i think the hdd is spinning as well but the hdd light won't turn on. The only lights that turn on are power and battery, both green.
This is the one that I got Toshiba Satellite® L305D-S5934 15.4" widescreen Laptop do you think it's not related to the new adapter I got? Would it be just a coincidence it stopped working after 11 days of using it?

**sharder8** · April 5th, 2011, 11:08 AM

Originally Posted by ToshibaL305D

Let me just correct what I said. The laptop is not entirely dead. I can power it on but the screen stays off. The cooler is spinning, dvd drive is working, i think the hdd is spinning as well but the hdd light won't turn on. The only lights that turn on are power and battery, both green.
This is the one that I got Toshiba Satellite® L305D-S5934 15.4" widescreen Laptop do you think it's not related to the new adapter I got? Would it be just a coincidence it stopped working after 11 days of using it?

Coincidence, yes.

Check the RAM first and then plug a monitor in. Could be the memory, LCD screen, screen inverter, or MoBo. Time to find out through elimination.

Also could be the battery shorting it out. Leave the battery out and just use the AC. Battery could have died while in standby or hibernate. With battery out, un-plugged AC, hold the power button in for 15 - 30 seconds. Plug the AC back in and turn on. If good, try with battery back in.

Harder

**ToshibaL305D** · April 5th, 2011, 11:13 AM

Thank you for the replies sharder8 and stroyal. I will send you a PM with the steps I have performed so far, to not deviate from the topic.

**NILI** · May 9th, 2012, 11:21 AM

Originally Posted by shizzzon

it doesnt' matter!

'Voltage is THE most important part in terms of properly running electronics. Amps cannot directly damage a product because you either have enough or you don't.

Typically, if you do not have enough amps, the device will never operate.
Now, if you just had JUST ENOUGH, it can either make a device work slower than normal or prematurely kill it because it's beggin for power.

'.

Hey! Totally new here.

Related to the subject would like your advice concerning a rechargeable battey for a laptop:
Original battery has a 14.4V /4300mAh.
There are two choices for a compatible battery: One with a 14.4V/4400mAh, and the second with a 14.6V/4200mAh. The first battery is almost the same as the original. From what you write I understand, that the amperage shouldn't be less than requiered. The switchmode power supply has an output of +19V/4.74A.
1. Could I use both a higher voltage and an mAh?
2. Is it just good to use the 14.4V/4400mAh battery?

Thanks for help. NILI

**stroyal** · May 9th, 2012, 03:26 PM

Welcome to TechIMO!

You should still start your own post.

I can't say if .2volts, will matter, but can make a few observations.

The mAh isn't the measure of the amps the battery can output it is the measure of the length of time it can it can output that.

The power supply has to be more voltage than the system, in order to charge the battery, so that is most likely transformed/voltage regulated down to 14.4 volts.

As the battery discharges, the voltage drops, so it is probably designed to run from 13,? to 14.4.

I wouldn't run a higher voltage, unless I was absolutely sure it is OK.

Seems to me that a battery has basically unlimited output amperage, at least way beyond what a laptop will draw.
Your power supplies A of 75 rating is the amp output, at least the max you should subject it to, as it will put out as much as you connect it to, until it overheats.
SO the only issue, is will .2 amps hurt anything.

**Undeadlord** · May 15th, 2012, 08:29 AM

Holy crap this is an old thread

I hope its still helping people!

I think your first choice is the best, from what I understand voltage needs to be the same, and amperage if abit lower is OK, system may just run slower. Again based on what IO understand.

Undeadlord

**stroyal** · May 15th, 2012, 09:30 AM

There are 2 amp rating here.
The OP has given us the rating, of the batteries length of operation mAh

There is another rating in plane old amps, that tells you how much power it is capable of putting out.
My Toshiba only tells the amps, not the time, for some reason 3.95amps.

If the OP doesn't have an amp rating, it can be pretty closely deduces, by converting the input to watts, then back to amps, and volts using the output voltage.

volts x amps = watts
watts / volts = amps

I don't think it will run slower, for 2 reasons.

The rating is for time, and amount, not the rated output amps of the brick.

The brick, like any electrical device will put out what the laptop calls for, regardless, of the rating
The source can't regulate itself, only the device controls the amount of amps.
All sources will put out as much as the device asks for, until they melt or burn up, or discharge.
This is why we have circuit breakers, and why short circuits are so dangerous.

When it overloads, the voltage will start to change, and this could cause problems with the laptop
It won't be a slow down, just all screwed up, to crashing.

**Undeadlord** · May 15th, 2012, 10:52 AM

Thats interesting, I know with HP laptops, if you plug in an adapter that does not have the right voltage or amps for what the laptop needs, you actually get a warning message on boot up. That the laptop will be running slower until you insert the correct AC adapter.

**stroyal** · May 15th, 2012, 11:45 AM

The laptop must throttle. itself, when it senses the wrong voltage, so I'm sure you are correct.

I just meant voltage alone would, not slow it down.

I don't know completely how a laptop is wired, but the battery must go through a voltage regulator.
The AC adapter may also go through an additional voltage regulator, or the same one the battery goes through.

This would give the laptop the capability to keep the volts steady, while limiting the amps available (meaning the overheating/voltage failing point), then the laptop could throttle itself, when it senses this condition.

Just guessing though.

**smarcuss** · May 25th, 2012, 07:45 PM

I have a router that requires a 2.5 amp and I have a power supply that when plugged in does give power to the router. I was wondering if the Linksys that specs say uses 2.5 amp and I have an power cord rated at 1.0 would that blow the power cord?

**stroyal** · May 26th, 2012, 09:41 AM

Welcome to TechIMO!
You should start your own post.

I don't know what you mean by blow the power cord, but depending on how heavy duty, or not, that it is built, it will overheat to some degree.

By drawing more amps than it is designed for, the voltage will fall off.

If it over heats too much, it will fail, but being UL approved, it probably has an internal circuit breaker of some kind, so it shouldn't melt the cord.

Now what the router actually draws, and the power supply, can actually put out without overheating, is the bottom line, but it is not a good idea to use a power supply that puts out less than the system requires.

If the router, really draws 2.5 amps, then that's what it will draw from that 1 amp power supply, regardless or what it is rated for.
As said though the power supply will make up the difference, by overheating, and reducing the voltage.
If pushed far enough, it will fail.

**saamee** · July 17th, 2012, 05:11 AM

Originally Posted by Choub890

Ok so... Behind my laptop it says (just saw this): DC rating: 19V/4.74A. I am confused as to what i should consider to be the true DC rating... My AC Adapter says 24V/1.5A, my battery 10,8V and now this new reading. Which one is it?

you should get the 19v//4.7A or 19V more than 4.7A .
voltage must be equal A(Ampere) must not be less than rated value. in your case laptop says 19v 4.7A so you can get 19v 4.7A,19v 5A, 19 6A.....
ibrahimsaamee@yahoo.com

**memoonamike** · July 20th, 2012, 05:49 AM

I do not know it is the right place or not to post this topic but when I do not see any place so I decided to post it here.
Hi everyone........!
My name is Memoona Mike and I'm new here. I'm professionally a writer but I like to get more knowledge about the every field of life because it is useful for me so this is the reason why I'm here. I hope we will have a good time and I found things that I don't know before.

**stroyal** · July 20th, 2012, 08:22 AM

Originally Posted by memoonamike

I do not know it is the right place or not to post this topic but when I do not see any place so I decided to post it here.
Hi everyone........!
My name is Memoona Mike and I'm new here. I'm professionally a writer but I like to get more knowledge about the every field of life because it is useful for me so this is the reason why I'm here. I hope we will have a good time and I found things that I don't know before.

Welcome to TechIMO!

You should always start your own post.

A message like this, should probably be in Community.