I just bought a 2nd hand laptop with a missing power supply (HP easynote Ls). It's up in the air if this thing actually works so I want to hook up a bench power supply to test it out before I buy an adapter. The laptop requires 3.42A at 19 volts. My power supply (HPS-3025) can deliver no more than 2.5A. I believe the power supply has a constant voltage output and a current limiter.

The power supply should be fine, but what about the laptop? It may start with the low current, it may not, but can I damage it trying this? What if I disconnect the battery and harddrive to keep power consumption as low as possible?

 

I don't think it will damage the laptop if the voltage is less than it should be - but of course it may not work properly.
If it works on the PSU, all well and good, but if it doesn't then you will be none the wiser. You won't know whether it didn't work because it doesn't work or if it failed because of a voltage drop.

 

I don't think it will damage the laptop if the voltage is less than it should be - but of course it may not work properly.
If it works on the PSU, all well and good, but if it doesn't then you will be none the wiser. You won't know whether it didn't work because it doesn't work or if it failed because of a voltage drop.

Do you mean current?

 

Just set the voltage to 19v and maximum current limit,with correct polarity the laptop will draw its own current as needed.

 

Do you mean current?

I mean that if the laptop draws more current than the PSU can supply then the output voltage will drop.

 

Will the voltage just drop or will there be other effects of to much current draw.
AHW

 

Follow instructions in post #4.
Leave the laptop closed and charge the battery for up to 8 hours (assuming the battery is not on its way out).

 

I just bought a 2nd hand laptop with a missing power supply (HP easynote Ls). It's up in the air if this thing actually works so I want to hook up a bench power supply to test it out before I buy an adapter. The laptop requires 3.42A at 19 volts. My power supply (HPS-3025) can deliver no more than 2.5A. I believe the power supply has a constant voltage output and a current limiter.

The power supply should be fine, but what about the laptop? It may start with the low current, it may not, but can I damage it trying this? What if I disconnect the battery and harddrive to keep power consumption as low as possible?

You might get away with charging the battery as long as you don't try to operate it before its fully charged.

 

The 3.42A is likely the current draw when its charging the battery, CPU pegged to 100%, fans going full speed,etc..
It will probably draw much less during normal (not maxed to capacity) operation..

Just don't try to run extreme benchmarking tests,etc.. and it should be just fine assuming you set the benchtop supply to 19V..

I doubt a computer would be hurt if the voltage were to sag..