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Post by gregstv on Apr 10, 2016 3:52:03 GMT -5
Ill test the rest of these boards here and might hit you up for some repairs soon mate No Problem, Once the rig is up and running, repairs will be a lot easier. I will make some board extender boards as well.
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Post by gregstv on Apr 10, 2016 3:36:11 GMT -5
Thats right the pins are reversed between the 8 and 9 inch MEC tubes. I notice the RGB amp is upside down. Since you are building this set you can make room for that as the other two tubes will need to rotate. If they hit the convergence tray cover plate perhaps you can just turn the tubes over so the end stages are the right way up. With raising the convergence tray cover up and cutting some off it so the tube is level (not pointing upwards) there is heaps of room between the end stage and the convergence tray. If I turn the tubes over the high voltage cap is very close to the metal tray and I would need to modify a lot more to mount the tubes. It could be done. Had a lot of fun with this today.
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Post by gregstv on Apr 10, 2016 1:37:21 GMT -5
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Post by gregstv on Apr 9, 2016 19:35:19 GMT -5
Maybe a bit of non-corrosive silicon to help support them (RTV3140) seeing they are on the underside. Looks good to me. I reckon i might do the other surface mounts the same way with FRs, some of them can go on the under side as well. the surface mounts mostly tested fine in the circuit, but when removed they were way out. I change them even if they test ok. The new ones should have better specs. I think of it as a prevention measures. These caps are old and could be failing under load. Its a big job to recap a projector, but I believe its worth it.
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Post by gregstv on Apr 9, 2016 5:18:28 GMT -5
Hi Guys, I have started to put together a 908 as a test jig to do board repairs and mods. The 909 main board and front tray fitted quite easily into the 808 frame. Mounting P18 tubes with 919 neck boards will take some fabrication. I am think of mounting the tubes level so the point directly at the screen at bench height. No jacking up the back of the projector. Does anyone no what the connectors are called or brand that plug into the neck boards. I may have to make some of these cables. Thanks, Greg.
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Post by gregstv on Apr 9, 2016 3:47:05 GMT -5
Maybe a bit of non-corrosive silicon to help support them (RTV3140) seeing they are on the underside. Looks good to me.
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Post by gregstv on Apr 2, 2016 3:23:13 GMT -5
Any pictures of the problem?
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Post by gregstv on Mar 23, 2016 22:07:44 GMT -5
Added some caps to the rails on the HFA1100 amps on the switcher, + and -5V. I put them across the .1's. Some of the later boards had a 47uf on the +5 volt line at each chip. I added a 100uf to each rail on each chip. Also changed the switching transistor to a BFR92 on port 3. I will get some pictures and post them. I am using a MOOME internal card on port 3. I have reduced the visible snow quite a lot, but I can still see it if I look into the lens. More work to do as time allows. I have ordered some high quality caps to try in place of the 4.7uf (C217,317,417)coupling caps on the RGB driver board.
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Post by gregstv on Mar 22, 2016 14:55:34 GMT -5
Yes you would loose that adjustment. Not worth it in your case until you get better tubes. The other caps would still help with noise. I plan to make some more changes as I can still see noise or snow on the screen. The noise is only visible during moving picture. The paused picture looks very clean. I think this is the noise that Mike has been chasing on his Marquee
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Post by gregstv on Mar 22, 2016 4:14:46 GMT -5
Adding the caps reduced noise or snow on the screen. Still have a way to go but it does reduce the noise. Removing the gamma also helped reduce noise. Other than that I didn't see a problem. The internal gamma on the Barco wont work any more. Removing this chip is something Mike P did with his Barco mods as well. It would be easy to put it back if you want internal gamma adjustment.
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Post by gregstv on Mar 21, 2016 3:57:02 GMT -5
Pictures of the 2 22pf caps and the Gamma chip removed.
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Post by gregstv on Mar 20, 2016 0:09:50 GMT -5
Did the video mods to the 919 that I did with the 808s + a few more. It defiantly helped reduce the noise. I have been checking what helps by looking into the blue tube. You can see like snow on moving pictures. With the mods this was reduced. If you look into all 3 tubes you notice the blue is the worst. Green is a lot cleaner and red is cleaner again. With the mods the blue is about where the green was and the green is as clean as the red. Its producing a very clean and smooth picture. I will post some screen shots soon.
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Post by gregstv on Mar 19, 2016 5:09:48 GMT -5
Is the splitter a R762907. I have one of these. I think its from a 7 series. Would be good for a spare if it would work with the 919
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Post by gregstv on Mar 13, 2016 4:23:31 GMT -5
Hi Guys, I have for sale a New old stock Hi res blue MEC tube. The tube is New in its original Barco box. Part number is R7627616K Asking $300au ONO.
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Post by gregstv on Mar 11, 2016 16:46:56 GMT -5
Also use a tiny bit of thin resin core solder. This will add a bit of flux and help the joint reflow. With the age of the boards the solder is dry and needs a bit of flux. When you are done clean with IPA. I use a pressure pack of IPA from J-Car and a small brush. When your finished it should look like new. If there are heavy ground planes you will find warming the board up will help a lot.
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