ratep2001 Posted January 23, 2016 Share Posted January 23, 2016 It seems to be quite a common problem for Sanyo projectors, described on the internet and in videos on Youtube but not for my PLC-XC56. The unit turns on, there is a blue Sanyo screen on the wall counting down from 30, but after a while the unit will start cooling down, turn-off the light and the red LED close to Power button starts flashing fast. As people suggest, the problem is usually in a broken fan, so I dismantled the whole thing and came down to the fans in the bottom. It seems that they are all spinning when I apply e.g. 6V from an external power supply, and for the bigger fans in the sides I could see myself that they were operating when the unit was powered on. So I mounted everything again, turned the unit on and started measuring on the fan middle pin with reference to ground (black wire). They are all low, not like I was expecting 50% duty cycle from a tacho feedback. After looking at some datasheet, it seems that at least one of the fans has a locked rotor indicator instead of a tacho, which goes high when the rotor is locked. So I believe that all fans they've put in this unit have a locked rotor indicator. I measured the middle pin on all fans and since they are all low, everything seems to be just fine (no locked rotor alarm). Where should I look for the problem next? Do you have any good idea about what is going on with this projector? Link to comment Share on other sites More sharing options...
Gerry Faurie Posted January 25, 2016 Share Posted January 25, 2016 The led next to the on/off is Lamp warning? - maybe its the lamp causing the problem - if its an old lamp with many hours done The fans have 3 wires and they sense current flow- normally if the fan slows down or stops it sends a high signal to the micro to shut down the projector Have you checked the filter /filter counter?? - but normally this led would flash if a problem here Link to comment Share on other sites More sharing options...
ratep2001 Posted January 25, 2016 Author Share Posted January 25, 2016 The LED flashing red is the one above the on/off button - the text immediately above it says "Power". The "lamp replace" LED is beside the power and is not activated, so I doubt this problem has something to do with the projector lamp. I agree with you with regard to fans: although many posts mention tacho feedback, it is indeed a simpler locked rotor feedback (e.g. option -53 is visible on the Nidec fan) which goes high in case of failure. I didn't measure any high signal, so fans are ok. I haven't checked the filter and associated counter - I also expect a different type of warning in that case, but I also don't know how to check this one when the screen shuts down immediately. Isn't it possible to troubleshoot this projector via the LAN connection or the controller connection (looks like RS232 or alike) and a piece of custom Sanyo SW? What about the service manual for this projector - does somebody here on the forum have it and can share it? I believe this manual must state in which cases this red LED will flash... Link to comment Share on other sites More sharing options...
Gerry Faurie Posted January 27, 2016 Share Posted January 27, 2016 I don't have any Sanyo Software to download the error codes Do all the lights come on after the Red (Power) starts?? You say the screen goes Blue with the Power management signal counting down - this indicates the lamp ballast /Lamp should be ok - I think these projectors have the scroll/filter detection cct like the xp range and many of times had these shutting down when scroll time is up but then the projector goes into alarm mode where all leds on top flash Link to comment Share on other sites More sharing options...
ratep2001 Posted January 30, 2016 Author Share Posted January 30, 2016 I am not sure I made some progress today, but I started troubleshooting with an RS-232 interface and terminal software to the Control port. Asking the projector "CR0" while the red LED is flashing, I got the answer "21" meaning "Cooling down is in process after Power off due to lamp failure". I am in doubt why the projector Lamp replace LED is not flashing, if there is something wrong with the lamp? On the other hand, this error code probably also covers ballast failure etc. which cannot be solved with a mere lamp replacement, so further troubleshooting might be required. I checked the lamp timer with command "CR3", and it answered with 3262 hours. Lamps are specified for 4000 hours (typical), so the lamp might require replacement but I can see the blue screen and switching between inputs so the lamp+ballast works. Can it be a kind of SW limit, when the counter for lamp hours is so high? How does the projector come to the conclusion that there is a lamp failure? Any clues on how to continue troubleshooting from here? Will resetting the lamp timer like in the case of replacing a lamp remove this error? Link to comment Share on other sites More sharing options...
mac.calder Posted January 31, 2016 Share Posted January 31, 2016 I would say it is more likely the optical sensor has failed - basically there is a small sensor which detects when the lamp has struck. Do you continue to hear the sound of the ignitor attempting to strike the lamp after the projector lamps on? If you hear it continuing to attempt to strike I would almost guarantee it is an optical sensor issue. A 4k lamp hour lamp will pop up a warning at about 3900 hours... it will not auto-turnoff without giving you a very distinct warning at least. Link to comment Share on other sites More sharing options...
ratep2001 Posted January 31, 2016 Author Share Posted January 31, 2016 Thanks for the answer. I don't hear the lamp ignitor striking, in fact everything seems working quite well until the lamp turns off and the projector starts flashing the red lamp. Is it still worth checking the optical sensor (if I can find it in the service manual) or should I be looking after failure some other place? I would say it is more likely the optical sensor has failed - basically there is a small sensor which detects when the lamp has struck. Do you continue to hear the sound of the ignitor attempting to strike the lamp after the projector lamps on? If you hear it continuing to attempt to strike I would almost guarantee it is an optical sensor issue. A 4k lamp hour lamp will pop up a warning at about 3900 hours... it will not auto-turnoff without giving you a very distinct warning at least. Link to comment Share on other sites More sharing options...
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