Unfortunately Eaton in California never did support the Grundig 700, nor are there any repair facilities that I know of.
The Grundig 700 originally manufactured in Portugal back in the 80s and 90s
I believe you’re thinking of the 750 and 800 series which is manufactured in China
Power supply might be the problem area, battery operation? That might separate the two power issues.
Did it just die? Or fade away?
There used was an older gentleman in Sparks Nevada who are used to be able to repair them but I think he’s passed away, parts are hard to come by if not impossible and other than doing some troubleshooting yourself that might be your best option especially if there is a component that’s bad. A once great radio and realistically still is, if you can keep them going.
best of luck 73