Sony VPL-FX40 tech issue

[mobyd]

One of my customers, a museum, has a bunch of VPL-FX40 video projectors. Occasionaly these things die (6 red blinks error code) and if they send them to Sony, Sony chucks in a new power supply. Ka-ching - $1000 please. As I do component level repairs on all their audio stuff, I said I'd have a crack at their projectors. In the absence of a service manual, I found that the power enters the PSU board, goes through 2 relays, thence to the bridge and DC/DC converter circuit. One of these relays is obviously a surge limiter as it has this weird fuse/resistor across the contacts (5R6 resistor and 2 amp thermal fuse inside a little white breeze block). In both projectors the 5R6 resistor was O/C. In the absence of an OEM part, I made my own by heatshrinking a 5R6 5 watt resistor to the undamaged thermal fuse. This was sort of a success - sort of because at some turn ons the resistor would blow again, other times the projector would run fine.
Q: Is the repair sometimes failing because the surge rating of the resistor is insufficient or is there some other downstream issue I should look at ?.
Cheers
Mike

[Gizmotech]

I think you'll find that it is a Thermistor. Usually you can do without it.