could a bad power strip cause problem to the mobile device?

Power strips either work or not.
It should only affect the device in that it may or may not get a charge.

Is the power strip also a surge protector?

If so, the surge protection has a set lifespan.
Once it cannot absorb any more surges, it will no longer do so.

On a modern surge suppressor power strip, once the surge suppressor has reached its limit, then no more power will be provided to the power strip.

On an old surge suppressor power strip, power may continue to be provided even after the surge suppressor no longer works.

Surge suppression is best for sensitive electronics, and power strips without it are fine for power tools and intermittant large draw items (they make surges of their own).

Most modern power grids are well adapted and do not have the surge problems of years ago, but there are other things that can cause issues where surge suppression may be desireable.

If the function of a power strip of either type is in doubt, I replace it.
They literally can be had for a couple or a few bucks at most any store.
Modern products are cheaply made and are basically disposable, unless you want to pay an exorbitant amount for some industrial grade or professional equipment.

I recently spent $30 on a very nice power strip at Harbor Freight.
I use it at work, it is steel contruction, has two USB ports for charging devices, and attaches to my tool box with strong magnets.

Honestly, I do not even know if it has any surge protection at all.
My guess is that if there is, it resides inside the USB port power conversion area.

Your device has a number of protections against 'bad power', and most likely is in no real danger.

But, electricity can be fickle.
Fluctuating/surging power could cause shortening of the lifespan of the charger for the device.

What exactly is the power strip doing that could be a problem?

 

Power strips are so cheap that if you're not comfortable dealing with electrical problems and your post implies that you're not then just buy a new one. But basically a power strip is just a few wires and connectors internally so if you can use a screwdriver and have a vague idea what you're doing then take the old one apart and take a look.

 

Like I said- unless it is a surge suppressor and a power strip (it will say on the tag on the back) then it either works or it doesn't work.

One or the other.

If it provides power and the on/off switch works, then it is fine.

Why is it on a table where it falls to the ground?
That is not good practice.

There are mounting holes in the back to hang the power strip from screws.

Hang it on a wall, under the table, or secure it to the top of the table.

Having such a thing that falls to the floor is not anything to deal with.
This must be resolved first, whether you replace the power strip or not.

And if you do choose to replace it, do not mind that 'a good thing is going to waste'.
You stated that it is years old, and we know that they are inexpensive.

Your safety and your devices are not worth the risk of not replacing an item that you have already gotten your money's worth from.

 

there really are no one strip is bad over the other. i just buy whatever is cheap. i think you are over thinking this. a power strip is not like a technical device like a phone or tablet. some can handle devices that need more power like a fridge. some have added protection for computers and such. but if you are just using to charge a phone or tablet, you do not need anything pricey.

also instead of drilling to hold a power strip, look into either double sided tape or velcro to adhere the strip to the wall.

 

Just put screws under the table.

The power supply will or will not say surge suplressor on the back of it, where the specification information is.

I would not waste my time with two sided tape or velcro, as these will not hold well or last.
Also, they both may damage the other surface when they fail or are otherwise removed.

Securing the strip to the underside of the table ensures that it will not fall, it is still accessible, and it is completely out of the way.

This will also tidy up the top of the table.

The screws do not need to be long at all, or ecen tightened, because the power tap simply slides over the heads of them.

That is exactly why those holes are in the back of power strips.

 

i use velcro. home depot has some that are really good. just get one rated for like 5-10lbs and you should be fine......and yes they ruin wallpaper or paint. but at least there will not be any holes.

 

Simply because that power strip looks OK physically on the outside, that has absolutely nothing to do with if it is or is not damaged in some way inside. The odds are just falling off a table a few times isn't going to do much, there are no moving parts or delicate components inside. It's not a big deal for a more tech savvy person to confirm if that power strip is fine or not, but since you appear to have doubts about it, instead of aggravating yourself so much just buy a new one and replace it. Life is too short to fixate on such minor details.