witch Posted June 17, 2011 Posted June 17, 2011 We have a NEC VT49 which has started to show a large yellow rectangle on the screen. It isn't overall yellowing, it is a patch that actually looks like it has been drawn! I presume this is dust? The projector has been up for 3 years and the date on it is Jan 2007. I have never had to get one mended/cleaned (no, no time to even attempt it myself). Is is worth doing and can anyone point me in the direction of a good company to do it down here? Thanks
Hightower Posted June 17, 2011 Posted June 17, 2011 It should be fine after a good optical cleaning - we used to send ours away all the time. Do your LEA support team not offer this service?
HaleStorm Posted June 17, 2011 Posted June 17, 2011 its either that of the coating on one of the internal lenses/light gates peeling, or as you say its a buildup of gack inside the light channels, it might be worth asking if your local university have a clean lab that do projector repairs, we have Sheffield and Hallam University's about20mins away from us and they both offer local schools cleaning services for projectors for 15quid per unit 1
Butuz Posted June 17, 2011 Posted June 17, 2011 Its quite likely to be the bulb. Have you got a spare bulb you can try in it? Butuz
Hightower Posted June 17, 2011 Posted June 17, 2011 Its quite likely to be the bulb. Have you got a spare bulb you can try in it? Butuz Will a 15w energy saving screw bulb fit
witch Posted June 17, 2011 Author Posted June 17, 2011 Do you really think it might be the bulb? I have never seen a bulb produce a yellow patch on the screen?
HaleStorm Posted June 17, 2011 Posted June 17, 2011 it could be ive seen a buld where the silver reflective stuff behind the filament has peeled off and it made the picture go all kinds of crazy
witch Posted June 17, 2011 Author Posted June 17, 2011 LEA don't offer a cleaning service and I don't think Bournemouth Uni does either. I will have a look and see whether I have a spare bulb to try...
Hightower Posted June 17, 2011 Posted June 17, 2011 Don't like it when the shoe is on the other foot eh?
bossman Posted June 17, 2011 Posted June 17, 2011 @witch: It will be part of the prism and if it is like certain Hitachi ones then you would be better off purchasing a new one as we do our own deep cleaning and this is what we have found to be the case. If on the other hand it has the different coloured glass slides like the Sanyo's then you can use propanol and special lens cleaning clothes to effectively bring up as good as new, we have deep cleaned around 10 lately which only took us 20 mins each. Have a look on the internet to see if someone has opened one of those models up and have a go yourself, it will cost you nothing but time
Marci Posted June 17, 2011 Posted June 17, 2011 Never really seen the need for a clean lab etc... I just take them home and strip and clean them on my kitchen counter... if it gets to the point where the displays need detaching from the prism then that's the only time it gets tricky but patience and blutak sort that (blutak screens in place on prism, lightly tighten screws, fire it up, and tap edge of each screen til the pixels all lineup properly, then tighten screws). Done it to Hitachi, NEC and Epson brands without any major fuss.
bladedanny Posted June 17, 2011 Posted June 17, 2011 ...we have Sheffield and Hallam University's about20mins away from us and they both offer local schools cleaning services for projectors for 15quid per unit Do we? Useful to know, thanks .
Butuz Posted June 17, 2011 Posted June 17, 2011 Do you really think it might be the bulb? I have never seen a bulb produce a yellow patch on the screen? It could be my dear!! Take out the bulb and then see if the yellow patch dissapears?? Butuz
witch Posted June 17, 2011 Author Posted June 17, 2011 Bulb, lamp, whatever - least I spelled them correctly I do NOT have any time to go pulling things apart, bossman. Being part-time at two schools means that I never have enought time to do my normal stuff, without adding to the list! It would take me a long time to do which would mean the teacher was without a projector for a while. Have searched and cannot find any info on cleaning it anyway. Definitely wouldnt try without some sort of 'how to' guide. TBH it is probably been caused by lack of filter cleaning as it is a job I hate and avoid doing if I possibly can. I will replace the bulb if I have a spare - but does no one know of anyone who will repair it for me down here?
Marc-Engineer Posted June 18, 2011 Posted June 18, 2011 How may hours do you have on it? has the lamp been changed at the correct times IE. 2000Hrs it sounds like its had an over run lamp beyond it hrs and the high UV then produced has scorched the polerising filters, Deep cleaning is not an end user task, it has to be completly dismantled in a dust free room and rebuilt optical engines are not ajustable by end users. The only other things it may be is a collapsed lamp but it would be highly unusual, last thing it may be also rare would be LCD problems, i would need to see it if you IM me a picture i can help you more or you can ring me for FREE advice. Marc projector Engineer 1
witch Posted June 18, 2011 Author Posted June 18, 2011 It literally looks like someone has drawn a large yellow rectangle with highlighter pen, about 30cm per side, on the LHS just below the centre line. The teacher was convinced it was on the board and even came and asked me what to use to get pen marks off with!!
Butuz Posted June 20, 2011 Posted June 20, 2011 I've actually got a yellow lamp projector here so your not alone witch. The HOD doesnt want to buy a new bulb so it looks like it's going to be staying yellow :S Butuz
Marc-Engineer Posted June 20, 2011 Posted June 20, 2011 I need more detail to help you with it even a photo of it would help. email it to me for FREE advice. IM me for email address as i dont know if i can put it on here any other way. Marc Projector Engineer
witch Posted June 20, 2011 Author Posted June 20, 2011 Will try and sort out a photo tomorrow, thanks
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