do somebody a/no service

do (one) a service

To help or aid one. Sharon did me a service by getting that jammed paper out of the printer.
See also: service

do (one) no service

To do something that hinders or is detrimental for one. You do your kids no service by catering to their every whim.
See also: no, service
Farlex Dictionary of Idioms.

do somebody a/no ˈservice

(formal) do something that is helpful/not helpful to somebody: She was doing herself no service by remaining silent.
See also: no, service, somebody
Farlex Partner Idioms Dictionary
See also:
  • do (one) a service
  • do (one) no service
  • be at (one's) service
  • be at somebody's service
  • of service to someone, be
  • at service
  • at someone's service
  • come into service
  • go into the service
  • see service