Replaced tape in No 500 in my jotter (7)
I believe the answer is:
notepad
'jotter' is the definition.
(I've seen this before)
'replaced tape in no 500' is the wordplay.
'replaced' indicates an anagram.
'in' means one lot of letters goes inside another.
'500' becomes 'd' (Roman numeral for 500).
'tape' is an anagram of 'tepa'.
'no'+'d'='nod'
'tepa' put into 'nod' is 'NOTEPAD'.
'in my' acts as a link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for notepad that I've seen before include "Jotter; pocket computer" , "writer's block" , "PC" , "scribbler" , "A secretary may have one" .)