Mark serial number to repair

Hi! how are you?
I use ERP NEXT to manage a store of electronic devices with a serial number.

I would like to know how to mark the serial numbers that clients return to me and I have to repair.
I’m not looking to make a return note, just mark that serial number as being under repair to find out
later to get a report and find out how many serial numbers are under repair.
I can do it with tags, but it is very heavy to mark one by one.
Is there a topic that tells me how to manage returns but without making a credit note?

Thank you very much for your time.

Did you figure a solution? I am also looking for a way to handle serialized item repairs that the customer sends back to us and happen on premise.

This is stil not comfortable to pull out in any way. Or I have not found a way to do it yet properly.
What is the current way people are using to handle repair returns of machines with serial numbers?
Stock Entry->Type:Maintenance, input serial number. OK the item is in my repair warehouse now. What then? Can’t create Workorder or Job. How do I assign a repair job to an employee? How are sub-items used for repair tracked? How do I pull a report of serial numbers and what repairs have been done over years?