I have a device which has a broken 6V 200mA AC/DC switching adapter. I assume it’s dangerous or maybe impossible to try and use an adapter with output AC 6.5v 500mA?

Someone more knowledgeable than I will come along but as far as I’m aware the extra .5v shouldn’t make any difference and the device will only take what it wants i.e. 200mA max so I think it will be fine.
Happy to be educated otherwise though.

I’d use it without hesitation.

As said above, id use it.

The device will draw only the power it requires. If it only takes 200Ma, plugging in a 1000A charger would make no difference.
As for 0.5V difference, its unlikely to make much difference, probably within the standard tolerance, the equipment may have internal voltage sensing though which might pick up on the elevated voltage and think the battery is charged (elevated voltage feedback signal). But youve not said what your connecting too (is the device in charge of the charging or is the charger).

But if the connection is the same, id use it.

As above, fine to use as current is drawn not pushed. A 1000mA device plugged into a 200mA power adapter is bad though!

But…just be aware of the polarity of the connector – needs to like for like obviously.

It’s for a kids gro clock so not charging as it’s constantly plugged in.
Is it easy to find the polarity?

Turns out the one mentioned above didn’t fit due to slightly different pin design. However I have a 7.5v 0.5A adapter which fits – any issues with that?

Doubtful.
I’d use it.

The polarity of the connector should be indicated be on the adapter somewhere.

But 7.5V into 6 – not sure, you might damage the device. Unlike current, voltage is pushed.

I wouldnt…

I didn’t in the end. Thanks!

The question no one has asked us why it’s broken the old one. Frankly the output of the power supply is broadly* irrelevant if it fried it because of a fault.

*Certain faults could make this very relevant mind.

I know you aren’t going to do it now but the other thing to check in these situations is if the input is AC or DC.  You said the dead adapter was AC/DC (I presume you mean converts AC to DC) and the replacement was AC (which I think means AC out) so it wouldn’t work anyway.  You can’t feed something that needs DC with AC.  You might get off with feeding DC into AC sometimes but that’s another matter

@dangeourbrain
The cable has slashed at the connector as it got caught behind the bedside table.