pls help in monitor troubleshootin

[miox]

hi, need help in troubleshooting a proview 17 inch monitor, it was a dead set then i replaced a defective power mosfet & a high speed rectifier near the HOT area, now the monitor starts up but after a second the HV shutsdown leaving only the indicator led on, i think maybe its a excessive HV thats why its shuts down, i checked the HOT collector output of an identical monitor & i measured about 600 VAC, when i measured the HOT collector of the deffective monitor upon startup it exceeds the 4000VAC range of my meter "fluke 83 series 3" ,then it shuts down, maybe its the xray protection thats shutting down the HV, im not sure though, can any one pls help me how to unrstand why im measuring excessive HV & the components responsible for that fault, thanks:)