When a unit dies with Guardian Angel, do the other equipment stay attached?

Yes, when a unit is saved by Guardian Angel, all other equipment remains attached to that unit.

According to RiftJudge FAQ #674 and FAQ #8433, when a unit with Guardian Angel dies, the unit never technically "dies" or leaves the board because Guardian Angel acts as a replacement effect. The unit is instead healed and recalled to the base. Because the unit remains in play (moving only between board zones), it retains all buffs, damage, exhausted status, and attached equipment.

As stated in Rule 718.6, attached cards cannot be moved separately from the top-most card they are attached to, and since the unit itself is not leaving the board, the equipment stays attached.