Any help with Hitachi CP-RS55 Projector

[karlfoxman]

Hi there,

I have the projector above and it has a bad PSU, it started like this. Powered on bang 6.3amp fuse blown, Bridge rectifier blown, Mosfets to boost rectified supply up to 370v for the lamp ballast.

Ok so we replaced all components blown including the PFC chip IC101 (FA5501) and also some SMD resistors that had gone open circuit. Now we powered the unit on using an inverter and with current limit as to save the components for another distructive bang. We could find no Vcc to the chip that supplies the primary transformer and gives the supplies to the entire projector. I am really finding it hard to get this to work now, I cant seem to get any output from the IC201 (FA5508) PWM DRIVING Q201. I have attched schematic for the psu and also pdf of similar IC FA5542.

Obviously IC101 will not operate without IC201 working first, as the 4.1v needs to be there to turn IC101 via opto coupler PC203.

Anyone have experience with this or point me into any clues where to look now? Thanks very much!

http://www.fujisemicon-elis.com/en/p...tnumber=FA5542