budwich
Badcaps Legend
Last Activity: 07-22-2024, 12:41 PM
Joined: 07-24-2015
Location: Kanata Ontario
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It appears that the 3 lcd panels are all the same (ie. monochrome). Replacing the prism assembly brought everything back to "normal"....
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I haven't gotten much further on this in terms of success. I have question though about the LCD panels on an 3lcd projector. Are the panels all the same... meaning "monochrome" and that basically only filters / polarizers are the "color component" or is each panel a "normal" LCD and only the appropriate "sub pixel" is driven for a given color? Depending on that operation, maybe the blue lcd panel has an issue and not necessarily only the polarizer stages.Last edited by budwich; 06-29-2024, 10:20 AM.Leave a comment:
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The picture is one from the green and one from the blue.... not the two from blue.Leave a comment:
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OK... I will see how this "surgery" can be done.
ADDED: attached is the out polarizers, Green and Blue paths. Blue one is definitely "burnt". Are these available anywhere at a reasonable cost?...Last edited by budwich; 05-12-2024, 09:12 AM.Leave a comment:
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You could be right about the green. I am "color deficient" with red / green plus... I can see colors but if one color is dominate, it "floods" any others in certain combinations. I have asked my "helper" who has good color vision what colors are showing at times to confirm things so some of those details that I have provided about colors are based on that confirmation.
Not sure that you understand what I have said. I have the prism block / assembly totally out of the machine. I can place a flashlight at the "out port" side of the...Leave a comment:
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:-( not sure I follow things in terms of "burnt"... will there be discoloration or blocked image? When I send an led light into the out side port of assembly, I can look at each panel. They all looked the same with good color, no blotches and "fog". I can clearly see the light source led cob element of the flashlight that I am using thru each panel.
So my question then, can I move the blue panel "sandwich" over to the red position and similarly put the red in the vacant blue area. Will this damage the drivers? Is there any voltages associated...Leave a comment:
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Here is the blue panel driver.... lots of inputs :-)...
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Attached is a block diagram of the video processing section. Not sure I know what I am looking for. :-(
My guess would be all the inputs going in to the IC1801 panel driver??...Last edited by budwich; 05-11-2024, 06:27 AM.Leave a comment:
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OK. Thanks for this. My understanding of LCD projection is very limited as I have only used and worked with DLP ones and mostly therein with hdmi interface issues.
I disconnected the red and green panel cabling going to the block on then displayed a menu. Prior to that the menu lettering was very yellow with pale yellow cast over the reset of the screen which should have been black / grey. With those cables disconnected, the pale yellow cast over the rest of the screen was more dark grey and there was a very faint sign of blue lettering. From what you indicate, that would seem to mean the...Last edited by budwich; 05-11-2024, 06:08 AM.Leave a comment:
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Sony Data Projector vplfh31 3LCD Blue missing
Got this projector which has a problem with a lack of blue. Menu text is very yellow... expecting white. If I input a signal from a test disc via hdmi, a red screen image shows a uniform red as expect. Green similar while the blue does show but with non-uniformity. Looked at the in-polarizers. They are all good and clean. Running the projector to expose the light area in the prism block, shows each color well represented, all looking about the same intensity from the naked eye. Looking at the prism block itself and sending a light source back into the "out port", the individual...
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Re: ROLAND DAC-15D only dry signal
You need to follow the input waveform around giong by the points that you have posted from the service manual. You previously posted waveforms from point "2" (I think). So you need to do the same for each point as identified by the pictures in the manual. The one of interest is at point 3.
Having said that, IF the voltage output was at 15v as you posted, it is possible that it might have taken out a few components that rely on the 7.x volts....Leave a comment:
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Re: ROLAND DAC-15D only dry signal
Doesn't look right. Check the voltages at both the zeners going into q1 and q2.Leave a comment:
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Re: ROLAND DAC-15D only dry signal
sorry don't know much about the dram function or for that matter, the overall processing itself. When I was dealing with the noise problem, I did the same as you... put in a nice clean 1khz waveform and followed it along til I found where it went bad / noisy and then started check components in the area thereafter.
Another question for you, your post showing the schematic shows a better "picture" than previous posts which I think you took from other sites. Do you actually have the "service notes" for the DAC15....Leave a comment:
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Re: ROLAND DAC-15D only dry signal
I can't add much more other than "good stuff". Are you able to get a trace "point 3" which is just after Q9... it should be some sort of chopped signal similar to what you posted in #16. I am not sure why you aren't seeing a "normal" sine wave. It almost looks like you are getting some form of "rectified waveform" instead.Leave a comment:
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Re: ROLAND DAC-15D only dry signal
you should be seeing some sort of similar 1khz wave form at the output of the LPF section at q8.
another question about your input.... is it a nice clean 1khz sine wave? and further along the input signal path, does it continue to be nice and clean or are you seeing a totally "distorted" wave at some point.... maybe the input portion has some "weird" gain or such that the input can be handled in the further processing down stream.Last edited by budwich; 10-27-2023, 09:07 AM.Leave a comment:
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Re: ROLAND DAC-15D only dry signal
ok... thanks. I am starting to get beyond my limited knowledge / experience (my roland suffered from noise / leaky cap). Anyway, I don't know what it means.... but you could be right as it is certainly digital. I think the levels seem "high". How big is your input 1khz signal. Further, how are you generating the 1khz... do you have other frequencies available just to see if the characteristic at IC7 changes with the frequency change?
At IC6 (after q9), both inputs should have a similar look. What are you seeing the...Last edited by budwich; 10-27-2023, 08:45 AM.Leave a comment:
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Re: ROLAND DAC-15D only dry signal
are you able to post a scope shot of what you are seeing at ic7 when you are saying "the signal is there"... what is the signal? My understanding is that it should be some form of "chopped analog" as I think that is what the two inputs appear to come from... ie. chopper chip... although i am not sure how the op amp before ic7 will handle that.... ie smoothing or otherwise.
In terms of the "only the chorus and flange effects" don't work... those are the only thing handled by this portion of the processing...Leave a comment:
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Re: ROLAND DAC-15D only dry signal
Check to ensure that IC5 has proper supply voltages ... this is a "chopper IC" thus after this point and after Q9, your 1khz input might look a "bit different" (not as well defined).Last edited by budwich; 10-22-2023, 10:59 AM.Leave a comment:
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Re: ROLAND DAC-15D only dry signal
Only have limited experience with roland (dac50xd) and operation in general. Looking at the schematic, if you feed in your 1khz tone, you then can check to ensure what you are seeing at the output of the master volume (the 2.9dbm)... the value isn't so important at this time... just ensure that you are seeing a good signal. That signal is fed to the processing stage via op amp ic4a. Check at that op amp output to see what signal you are seeing there... ensure that it is similar to what you saw at the output previously mentioned / checked. You...Last edited by budwich; 10-22-2023, 09:30 AM.Leave a comment:
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Re: ESD Diode on HDMI output of Yamaha a1050 RCVR
Well, I lifted the esd diode pack for the data0 and data1 pairs (in the same pack). No joy as the impedance to ground is still low (~6K) for either of the bad lines versus high mohm for the good lines. The only thing between the hdmi pins and the transmitter chip (256 pin) is some smd inductor pairs. I lifted the one involved. No change. It appears that the drivers involved in the data1 pair have an issue at the chip. I am not risking replacing the chip as one output is better than none... :-)Leave a comment:
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