Using Match and Index to highlight serial numbers

Hi Everyone.

I have a workbook which contains a number of sheets.

I have on Sheet1 a list of Serial numbers of products that have had recall repairs carried out.

Sheet 2 contains a list of customers who have had faults with their equipment, and along with it contains the serial number of the offending item.

If using VLookup, I only get the first instance of the offending serial number, but want to bring all subsequent events to attention as each event has a unique ticket number. If using a combination of Match and Index, I get the same outcome.

Any guidance on this would be fantastic.

Many thanks in advance, John.