Laptop power bricks interchangable?

[ROSALIEPIZZA]

I have an old Dell laptop the power cord tore at the moulding near the barrel and I was looking around in my spare parts for a cord with a barrel that fit the power socket and was going to solder a new cord to my dell brick. I have an old Compaq power brick with the same size barrel and before I started the task I was comparing the specs of each brick and they were exactly the same input 1.5 A output 19v---3.16A.
Is there any reason the compaq brick would fry something on my dell since the power appears to be the same
Thanks in advance if anyone could help

 

[SparkyJJO]

If the volts, amps, and polarity is the same then it should be fine.

I'm using an HP adapter on my gateway laptop.

 

[ROSALIEPIZZA]

how would i test polarity? the dell power brick uses a three prong plug while the compaq uses two prongs. Any advise from anyone?

 

[Itchrelief]

how would i test polarity?

If they have the diagram with the half circle and two lines it should be fairly easy. Just make sure they match.

edit: post has nothing to do with the # of prongs. in any case, I would suspect the third prong is just to save you from electrocution in case the wallwart malfunctions. As the DC output is semi-isolated from the AC mains by the transformer, the third prong is probably not intended to save your laptop from harm.