If the asset had a value of 100,000 and accumulated amortization was 100,000.
Then you would
Dr. Accumulated Amortization 100,000
Cr. Asset 100,000
Dr. Cash received from sale
Cr. Revenue
That would be the JE when you have fully depreciated the asset so that the book value of the asset is 0 (therefore you expected no salvage value from it, so anything is a bonus/income)
If the asset was fully depreciated but there was a salvage value..
So let’s say total accumulated amortization was at 90,000
The JE would be:
Dr. Accumulated Amortization 90,000
Cr. Asset 100,000
Dr. Cash received from sale
Cr. Revenue or Dr. Gain or No entry (depending on if you got cash of 10,001 or more, 9,999 or less or 10,000 even)