tā / zhèng / zài / gēng / huàn / sǔn / huài / de / sān / jí / guǎn / ràng / shè / bèi / huī / fù / zhèng / cháng

他正在更换损坏的三极管，让设备恢复正常。

He is replacing the damaged triode to restore the equipment to normal operation.