Infocus power supply isssue

[budm]

Re: Infocus power supply isssue

If the PFC Voltage booster is not working, the DC voltage on that main DC filter cap will only be = line voltage x 1.414, you will not have 339V without PFC working.


https://cdn.badcaps-static.com/pdfs/...f33e6f6571.pdf

[subarub4]

Re: Infocus power supply isssue

So I should be looking between the main and the PFC for something shorted or open circuit then? I was looking at D103 on the back of the board I think it's just reading both ways because it's in circuit, and for ZD204 it appears they are only using just one of the zeners.

I'm checking with a analog ohm meter

but yeah I suspect I was not going to see that voltage on the connector, One thing I might of been doing wrong as when checking for voltage on the PFC I should of been checking between VCC and the filter cap?

[budm]

Re: Infocus power supply isssue

Check for the DC Voltage of the VCC pin of the PFC IC and its Ground pin. I do not recall the IC of number of this PFC IC, it has been a long thread.

[subarub4]

Re: Infocus power supply isssue

Getting 0V from IC101 (PFC IC) checking with the ohm meter the VCC pin of the PFC seems to be connected to C117A, C117, C116 which seem to be connected to the FSU10A60 The output pin on the PFC seems to connect to the same SMD caps but connects to D107, Q602 & Q603

[subarub4]

Re: Infocus power supply isssue

A little update I got a Viewsonic projector that is a clone of the Infocus so they had the same power supply and mainboard, my projector starts up fine now.. I was STILL unable to find out why the other board still does not have power :-/

I checked the old with the new and the readings matched up :-/