Choose an Toshiba PA3290U-2ACA adapter with the same electronic  specifications as your old one. Make sure its plug size is compatible with the device you plan to use it with. To be sure, bring your device with you before you buy.
When replacing your old Toshiba PA3290U-2ACA adapter, look for one that matches the volts and milliamps of your old one. This information should be printed on the original adapter.

Determine whether the adapter should be regulated or unregulated. Simply put, an unregulated adapter does not always produce the rated voltage while a regulated adapter does. Because of this, regulated Toshiba PA3290U-2ACA adapters are also generally more expensive than unregulated ones.

There are some questions for ac adapter.

Question One: Is it OK to use a Dell laptop AC Adapter on a HP laptop?

Question Two: Can I use a universal power adapter to replace my AC Adapter?

Question Three: Can use a 18.5 volt ac adapter on 19 volt laptop?

Question Four: Can I use a higher amp adapter on my laptop?

Suggest a situation that you left you HP adapter home and your friend has a Dell adapter,it plugs and it charges.But at the same time a question following, will it do harm to your laptop or the adapter by doing this? Or what if your friend has a 18.5V AC Adapter with the same brand while yours original is 19V?  And will it be OK if his adapter is with a higer amp?

Maybe you are experiencing this situations now and feeling comfused.Then you must take a while to read the tips below.

Actually,it doesn’t matter whether two AC Adapters are with the same brand,all you need to follow is as bellows:

(1)    The Voltage

Must be within 10% of your original AC Adapters(Toshiba PA3290U-2ACA adapter) Voltage.

(2)    The Amps may be higher but they cannot by lower. If higher, no problem, for all

Electronic products only use as much current(Amps) as thay need but not how much provides.( For example, if the label of your laptop indicates 19V 3.15A, then the AC adapter with the voltage 18V to 19V all works with no harm doing to your laptop, and if you can not find the exact 3.15A AC adapter from these above, just select the next size higher in AMPS.

(3)    Check the connecter of your original AC Adapter(Toshiba PA3290U-2ACA adapter), and make sure the AC adapter you want to order matches this one.