[Rich]

This is a totally different unit.

I found a users manual online, and there is a brief mention of an internal battery. It's in the head unit somewhere, but who knows the type of battery, and how successful you will be if you replace it.

You certainly will lose any saved data or setup information. Of course, if the battery is dead, your data will probably already be gone!

It's up to you if you want to try to open the head unit and take a chance. If it's not working now, you'll have to buy a new one either way. You may be able to replace the battery and revive the unit. If you do replace the battery, I suggest performing a factory reset after you reassemble it to initialize the data.

If you've never taken apart delicate electronics before, perhaps get some help. Static electricity from just touching things inside can cause more damage.

If you were local to me, I could look over your shoulders and give you guidance, but it's difficult to give instructions via web postings.