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Post by mastertech on Dec 7, 2015 18:43:51 GMT -5
So when you say the keystone works, you mean the top and bottom key works?
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Post by tschaeikaei on Dec 7, 2015 19:43:39 GMT -5
Yes, speaking about pressing Geom then 2 on the remote for keystone.
It is top and bottom at the same time, affecting the whole picture.
But i think you know what this setting does. My projector reacts normally in that regard.
Seems only vertical settings are affected.
Vertical convergence and vertical geometry settings are not working.
Regards, Julian
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Post by mastertech on Dec 7, 2015 20:24:25 GMT -5
Yes, I just wanted to verify. I am trying to narrow this down to a specific location since your voltages look fine. Now since the top and bottom key work I was hoping that the V skew also worked. This would indicate that U9 is probably bad. Which it still might be. But V skew is not part of U9 which makes confirmation of U9 more questionable since V skew uses U11. Now part of U11 could still be bad while parts of it can still be ok. I don't think it is past this point since H and V size work ok and also KEY but this could also mean that the problem ic, if it is an ic can just be partially bad. And partial failure of U7 is also possible.
At this point I would possibly check the output of U7 with my volt meter on the working and non working outputs, while making those menu adjustments and see if you have controlled output on the non working functions of U7.
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Post by tschaeikaei on Dec 8, 2015 4:56:02 GMT -5
I'm at the university and can't do anything than read and think (which should be helpful in some cases  Just for my own brain: If a specific output is not present, there are four possible reasons. First, there is no input (to the FGM board). I kind of tested that using the other FGM in the projector. This worked. But there could be something bad in the signal chain between Mainboard connector and the IC. Second: one or more IC supply voltages are not present. We checked that. They're fine. Third: broken IC or broken part of an IC. Check if inputs are present and see if I can measure something on the output. Oh and before you ask. I have an oscilloscope. Fourth: something between the IC's output and the board connector to the motherboards. No that I know which IC does what i can understand what i'm doing. I'll buy some TDA 8444 on my way home and check. Might get an MLT04 and MC34074, to. SDA and SCl are coming from the CLM, right? They're digital I²C bus signals that get converted to analogue waveforms by the TDA8444 . U7 is the interesting one in this case. Those waveforms get amplified by the ICs U9 and 11 MC34074 Quad OPAMPthen mixed together with the top and bottom "MOD" (?) signals that are created on page 5 of the schematic, meaning on the FGM board. If i interpret the datasheet right, you can't multiply a value with zero and get an output. So i should measure at e.g. pin 3 AND 4 of U10 to see if i get BOTH inputs. My conclusion on this is: U7 or U9 and U11 are bad. If the TOP_MOD signal wasn't there, TOP_KEY would not work, to. Same for BOT_MOD (BOT_KEY would fail, but this works, to). So forget them both. U10 could be partially defective,to. Feel free to correct me! Regards, Julian |
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Post by Deleted on Dec 8, 2015 6:36:36 GMT -5
Just for the record. I once lost horizontal convergence on red and blue until I figured I had the connectors swapped  When you are in the menu's you want to converge blue but red moves and you do not see that than you go back wondering what the hell  Swap them with green and static is gone... |
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Post by tschaeikaei on Dec 8, 2015 7:13:41 GMT -5
Yes. That's the first thing I checked.
Regards,Julian
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Post by Deleted on Dec 8, 2015 7:47:42 GMT -5
Yes. That's the first thing I checked. Regards,Julian Yes I know it is on the focusboard in your case as you demonstrated. |
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Post by mastertech on Dec 8, 2015 12:36:35 GMT -5
I'm at the university and can't do anything than read and think (which should be helpful in some cases Just for my own brain: If a specific output is not present, there are four possible reasons. First, there is no input (to the FGM board). I kind of tested that using the other FGM in the projector. This worked. But there could be something bad in the signal chain between Mainboard connector and the IC. Most likely not since all signals come through on the SDA and SCL lines.Second: one or more IC supply voltages are not present. We checked that. They're fine. Correct.Third: broken IC or broken part of an IC. Check if inputs are present and see if I can measure something on the output. Oh and before you ask. I have an oscilloscope. Correct. Voltages measurements with DMM are more then fine.Fourth: something between the IC's output and the board connector to the motherboards. Not likely in your case.Now that I know which IC does what i can understand what i'm doing. I'll buy some TDA 8444 on my way home and check. Might get an MLT04 and MC34074, to. Wow. I would be surprised if you have a local supplier with some of these parts. SDA and SCl are coming from the CLM, right? Yes. They're digital I²C bus signals that get converted to analogue waveforms by the TDA8444 . Yes.U7 is the interesting one in this case. Those waveforms get amplified by the ICs U9 and 11 MC34074 Quad OPAMPthen mixed together with the top and bottom "MOD" (?) signals that are created on page 5 of the schematic, meaning on the FGM board. If i interpret the datasheet right, you can't multiply a value with zero and get an output. So i should measure at e.g. pin 3 AND 4 of U10 to see if i get BOTH inputs. I think you answered this down a little farther.My conclusion on this is: U7 or U9 and U11 are bad. If the TOP_MOD signal wasn't there, TOP_KEY would not work, to. Same for BOT_MOD (BOT_KEY would fail, but this works, to). So forget them both. Correct. Size is also included in these outputs.
However, it is possible if either or both of these lines had a signal that was there but off for whatever reason could cause an abnormality that may affect some things and not others.
U10 could be partially defective,to. Feel free to correct me! This is why I think you should check the outputs of U7 first and see where we end up. You have to start somewhere and that is the logical place. Of course if you can get these ic's cheap then you could just change them and then see what happens.Regards, Julian |
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Post by tschaeikaei on Dec 9, 2015 17:53:09 GMT -5
Ok, i fixed it. Had to change U3. Had to go down all the signals till the output of U3. Mostly using the scope. Oh and i need to get a scope with digital numbers readout. Should be much easier. I've gone through the whole chain, following the TOP_PIN signal. Noted every step first on a known good FGM, then on the failing one. I have a list and sketches of the signals i measured on the different ICs. Is it of interest to publish it? If I was gone through this way, it would have been faster. 1. Measure the output of U7. Yes-> got to step 2 No-> Vcc? Inputs? 2. Measure the output of U3. Yes-> go on further on the convergence amp module No-> Vcc? Inputs? No Vcc: Can't be.. the projector would not start if 15 or -15V were not present. No input: Check H_RAMP, H_PAR, TOP_MOD, BOT_MOD All of them ok? Check U7 pin5 and U15 pin5. And so on. Funny that it is not possible at all (even on 0.1V/DIV) to see any signal at the OPAMPS inputs. Nothing, even when crosschecking with the working FGM (and I have 2 of them now ) Oh and that damn electronics specialist dealer does not have anything. Not even the TDA8444. I paid 5€ for two 11W resistors and 12€ because i lost my parking ticket. And so on. Regards, Julian And thank you very much for helping me to understand and fix this, Mr. Sir Mastertech! |
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Post by mastertech on Dec 9, 2015 18:27:07 GMT -5
So you did not change any other part. Then you just changed U3 and now everything is confirmed working?
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Post by mastertech on Dec 9, 2015 18:34:42 GMT -5
Ok, now I see it. U3 is also involved in forming H-ramp and H-par.
That is why I said this earlier: "However, it is possible if either or both of these lines had a signal that was there but off for whatever reason could cause an abnormality that may affect some things and not others."
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Post by Deleted on Dec 10, 2015 6:43:10 GMT -5
Good work. I have to learn working with the scope and life boards one day too. Please post the list it is of interest.
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Post by tschaeikaei on Dec 13, 2015 14:28:08 GMT -5
VIDEOOk, after struggling with youtube there it finally is. I hope this helps a bit, redfox. Taught that may be better than a list. Regards, Julian PS: you know, english is not my mother language. That's why i don't find the right words sometimes. Be patient
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Post by Deleted on Dec 14, 2015 7:01:07 GMT -5
Ok I watched the focusboard project. I am glad that this was not a lost footage movie where in the end the experimentator is fried by the high tension Very instructive thanks! I will come back on it later. |
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Post by tschaeikaei on Dec 14, 2015 9:41:39 GMT -5
Yeah I worry more about x-rays than about 1 or 2 miliamps. Even if it's 34.9kV.
Good to see that it helps.
Regards Julian
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When you are in the menu's you want to converge blue but red moves and you do not see that than you go back wondering what the hell 
Swap them with green and static is gone...
