If the priest skips his homily, is the Mass still valid? The priest at my parish skipped it one week because our speaker system was down.
It takes A LOT to invalidate the Mass, much more than that.
Skipping a homily does not invalidate a Mass, no.
The rubrics allow the homily to be omitted “for a grave reason.” We can debate whether the reason here was grave enough, but it certainly does not invalidate a Mass.
Was it a daily Mass or a Sunday (or Holy Day of Obligation) Mass?
From the GIRM:
There is to be a homily on Sundays and holy days of obligation at all Masses that are celebrated with the participation of a congregation; it may not be omitted without a serious reason. It is recommended on other days, especially on the weekdays of Advent, Lent, and the Easter Season, as well as on other festive days and occasions when the people come to church in greater numbers.
Then the question would be if the speaker system being down was a serious reason.
(Honestly, that would depend upon a number of different factors: the health of the priest, the acoustic properties of the church, and so on)
Whether or not there is a homily has nothing to do with the question of whether the Mass was valid or an invalid attempt.