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Post by radiohead314 on Mar 15, 2016 17:11:08 GMT -5
Yes good point. I was looking at that too. Seems 30V must be there. I was wondering if perhaps that 30 V cap is still charged even when 30V is not there? It might even get charged by the hthd on the subboard?
In fact I did not dare to let the smps on for to long with the two leds. Now with one led I will measure the independent voltages tomorrow.
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Post by radiohead314 on Mar 15, 2016 16:26:28 GMT -5
Hi Dummyload. I did only put the set in standby without j30. and indeed hthd led comes up and f100 does not blow yet but that might be because i now have 3,15A fuses again. I had a 2A fuse that worked well in a good SMS. But I am a bit further. I found that removing the TDA solves it. Without the TDA and with Q101 the HTHD led does not burn. Now I have bought 3 TDA chips they all say TDA4601 but two measure different between the legs with the multimeter. One measured the same as the old and I tried that one seems that one is broken? Top two with infineon writen on them where in the smps. Left is the old one right is the one I tried. Have to try one of the others. They all say tda4601. Perhaps stupid question but is it possible that there are different versions?  Untitled by Radio Head, on Flickr |
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Post by radiohead314 on Mar 15, 2016 14:39:19 GMT -5
Ok one thing comes to mind. There was a crack in the glimmer sheet but the man at the electronics shop said that is was no problem. But perhaps this crack is conducting? With the multimeter no conductance is measured.
I know for sure that without Q101 the HTHD led does not burn. I also know pretty sure there is 0V on the base in standby.
Also Q101 measured only condcuting with the multimeter from base to emitter and from base to collector.
I tested and it is not the sheet.
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Post by radiohead314 on Mar 15, 2016 11:15:18 GMT -5
Ok I made it nice again and used different cooling pasta I checked everything twice but still not good. At the moment I am out of idea's. When I put the set in standby only with all boards removed except the PFC the green led of standby and HTHD burn on the subboard. So there is still something wrong but there is no power on the TDA. No short on the Q101 so unless the cooling pasta is shorting again I do not know what this is. The subboard is good. Tested on another SMPS. Now I have to think on what to measure. I do not risk letting it in standby to long as it will burn another fuse.  Untitled by Radio Head, on Flickr Only the standby led should be on. The other led is HTHD.  Untitled by Radio Head, on Flickr |
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Post by radiohead314 on Mar 15, 2016 8:05:05 GMT -5
Yes. Correct I only need the 325V from the rectifier and the TH on/off comes from the rectifier too.
If this all works we might make a HOW TO for when people want to repair there own SMPS.
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Post by radiohead314 on Mar 15, 2016 4:07:09 GMT -5
Yes thanks. I was thinking on this and since I know not what is working on this SMPS I will simple remove every board and disconnect the wires to the neckboards and remove the tray. As far as I can see I should be able to measure most voltages on the SMPS. I hope the PFC works without the controller.
Than when I am sure all are correct I shall try to disable protection on the HTHD and measure that one.
I could send the SMPS to someone for repair but I think this way I made it pretty save. If I forget something please add.
Have to place the jumper j30 to start without controller.
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Post by radiohead314 on Mar 14, 2016 14:04:21 GMT -5
Hi Casey I do not have them yet. We where hoping they would be high bandwidth neckboards for the 909 but the signals and voltages differ to much.
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Post by radiohead314 on Mar 14, 2016 11:43:08 GMT -5
Hi, You can test with the SMPS without Q101 in order to see if both TDAs (they share the power supply) get their supply voltage. The set might go into protection though. If you override the protection, make sure that the heater voltage to the tubes is disconnected. Otherwise You will burn the tubes (no H-deflection). If You manage to get it working without Q101, check the output voltages at the other part of the SMPS (e.g. +17V, +12V, -9V etc.). If those measure ok, then this part of the SMPS is OK and we only have to worry about the HTHD part of the SMPS. There check D114, R101, D101, D111, R103, R109 Regards, barclay66 Edit: You might want to read the TDA4601 datasheet. It will give You more information on its working and where to expect specific votages/signals. See here: www.micropik.com/PDF/tda4601.pdfOk you gave me some good ideas to test the smps without burning the tubes because what happened yesterday was close to a big disaster  I put the set in standby with the new Q101. I noticed that next to the standby led the hthd led burned green on the subboard. That was not good and I should have stopped than. But I had to turn it on  Now because the hthd that was max voltage I suspect was allready there there where no reasons for the system to hold down or go in protect. All voltages went green and I heare a spark. There was an image on the tubes but also vertical bright lines contrast was very low on my system luckily I also saw G2 being not there, retrace lines visible. So I switched off and thank God no tube burn. I replaced the smps. Switched on and again no G2 and vertical bars. I replaced the SMPS2 board too and while I put it in set was off I heared a crack again and now I found out both SMPS2 are bad. so if I test again I have to disconnect filament first but still the risk to blow the SMPS2 or horizontal. Well I have to repair one SMPS now and two SMPS2 boards. My guess is the cap on the horizontal was charged 325V and broke something on the HTHD line in SMPS2. Further testing i did only in standby with this SMPS and with the SMS2 and Horizontal removed. |
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Post by radiohead314 on Mar 14, 2016 11:18:42 GMT -5
I measured the components mentioned just to be sure. D114 ok R101 ok D101 ok D111 ok R103 ok R109 ok And I feel kind of stupid because in the picture it seems I made a spark gab? I think I have to find non conductive coolpasta first and be more careful with it?  Untitled by Radio Head, on Flickr |
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Post by radiohead314 on Mar 14, 2016 10:45:37 GMT -5
Ok it is not C102. I am also checking the possebility that the collector that is in the middle of the three legs somehow shorted to the heatsinc. Perhaps to much silver cooling pasta?
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Post by radiohead314 on Mar 14, 2016 10:30:17 GMT -5
Ok I did a first test removing Q101 and removing C102. Inserted a new fuse and the fuse does not blow in standby! The voltage in standby on pin 9 of the TDA is 0,8V and that is the same as the good smps so there is not problem with the power to high activating the TDA in standby. Also there is 0V on the base island of Q101. So why does the fuse blow in standby? Is it the only option left that I see that C102 is breaking under 325V? I checked there is 325V on the island that normally the Q101 collector connects to. This test seems to exclude the other voltages blowing the fuse at least in standby? I checked the diodes and resistors but will check again. |
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Post by radiohead314 on Mar 14, 2016 9:37:29 GMT -5
Ok I need some help here. I tried everything I could think of and am almost stuck.
I replace the transistor Q101 in the SMPS that switches the HTHD, the voltage for the horizontal deflection. The new Q101 is a 2SC3998 just like the old one. I tested it as a npn transistor and it seems good. Behind the Q101 is a thin sheet of plastic I applied cooling pasta on both sides.
I also replaced the pulsating TDA4601. A quick check on the pins made me belive it measured th same as the old one so I think the TDA was not broken.
Now when I switch on the Barco with the big button it should go to standby. From what I understand 325V (I measured) is going through fuse F100. It is on the collector of Q101 but since the unit is standby the TDA is not powered and Q101 has zero volt on the base so It should not conduct. I checked that with the fuse F100 removed and indeed the TDA has no power and Q101 has zero volt on the Base.
Now when I insert a fuse a normal SMPS gets 0.8V on the pin 9 of the TDA supply and it is still off (it needs 20V). So on my faulthy SMPS inserting the fuse should not activate the TDA in any way.
But what I see is that with the fuse the HTHD led burns on the subboard (subboards is tested ok) even in standby and the fuse blows. Also a crack is heared. After that only the standby led burns on the subboard. The subboard regulates the 9V standby that part works good.
So I conclude that the 325V that should be blocked somehow conducts through the transformator of the HTHD to ground. But in standby the base of Q101 is at zero so is the emittor. Q101 is tested again perfect. I took it out again. The TDA should be not working in standby but difficult to check. The only thing I can think of is that C102 is shorted at high voltage but checking with the MM gives it is ok.
So how to check the TDA further? Inserting a fuse blows the fuse. Perhaps disconnecting Q101 to make sure there is no conduction there? Than inserting the fuse and measuring if somehow the TDA is switched on in standby?
Or testing the other option that C102 is conducting at 325V? Seems unlikely to me and would cost me my last fuse I am afraid.
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Post by radiohead314 on Mar 12, 2016 5:52:51 GMT -5
Perhaps an interesting point for those using lug tubes in 1209s but also in Marquee is to pay attention to this KH grid. On the Marquee it is connected to ground with a 330k resistor but Barco says to use a bigger than 1Meg 1/2 Watt resistor there. Sony seems to use a 10 Meg. This is very important because the KH grid lowers the capacitance between all grids. Using the right resistor seems to improve the focus too probable because it lowers noise.
Now Eisemann says that the ground is not very clean on the neckboards so he uses grid 5 for reference. That should improve the focus even more. Because grid 1 and KH are on the same potential now there is no capacitive loss between them.
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Post by radiohead314 on Mar 12, 2016 5:33:17 GMT -5
From the discussion in the link below it seems that for LUG tubes to work in a 1209 or 1200 with the R762292 neckboards, the KH grid on pin 7 has to be connected to ground with a 1 Meg resistor. A better way is to connect the pin 7 (KH) to pin 5 (grid 1) to get lower noise. On the 1209 it means adding a wire. On the 1209s it might be necessary to drill the hole where pin 7 goes so it is disconnected from ground and can be connected to pin 5. Do not know exactly what needs to be done with the R762292 neckboards since I do not have one to check. Anyone? www.avsforum.com/forum/16-crt-projectors/1134455-new-green-p19lug-barco-1209-a.html |
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Post by radiohead314 on Mar 10, 2016 5:29:39 GMT -5
Ok I think I did that too so 270 280 is a good temperature. For the smaller parts the tweezers work good to. I try a suction device for bigger chips.
I have some switcher chips and small breakout boards for modifying the vim of the Marquee. But they are in such a small package I have to make these miniboards first. Will start a topic.
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Now because the hthd that was max voltage I suspect was allready there there where no reasons for the system to hold down or go in protect. All voltages went green and I heare a spark. There was an image on the tubes but also vertical bright lines contrast was very low on my system luckily I also saw G2 being not there, retrace lines visible. So I switched off and thank God no tube burn. I replaced the smps. Switched on and again no G2 and vertical bars. I replaced the SMPS2 board too and while I put it in set was off I heared a crack again and now I found out both SMPS2 are bad.
