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Thread: Running the XJ-A140 With Missing Diodes

  1. #211
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    I dont know if you guys saw this but i think its awesome..

    http://www.zemax.com/index.php?optio...=68&Itemid=164

  2. #212
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    Default Laser-less mod!!...

    OK guys, with thanks and respect to krazer and others for taking the first steps on bypassing these PJ's - I've decided to release the info on modding the projectors to work with NO laser diodes at all (and without any huge power resistors!)...

    I bought some A130 carcasses from Mr Briggs at the beginning of August. It took me about a week to figure out how to bypass the current AND voltage sensing on one of them. I'm sure the A140 will work in a very similar way, but may need tweaking somewhat.

    I also wanted to try adding the other LED colours to it, so I bought some Green and Blue Phlatlights at the same time. I put some basic code together for sequencing an RGB set of LEDs for these projectors - I haven't tried it yet and it's probably best to save that for another post!

    As for the mod, I'm sorry I don't have any decent photos at this point because my camera is crappy. I will "borrow" my Dad's camera and get some proper photos up in the next few days.

    It will make a LOT more sense with photos, but for anyone brave enough to try following the guide in the mean time, well, erm.... Best of luck!

    There could well be some info missing here as it's been four months since I messed with any of this. Hopefully, it should be correct, but I can't be 100%...

    Note 1: Remember that there is no temperature feedback from laser block when bypassed! So the fans may run at strange speeds etc.
    You could change the value of the 10K resistors (for the thermistor bypass) to see if the LD fan speeds change.

    Note 2: There will still be temperature feedback directly from the Red Phlatlight, so the fans might change speed to a certain extent.
    It appears to regulate the speed of ALL the fans even with this bypass (not just the one nearest the LED heatsink), but with this in mind...

    WARNING! - With this mod in place, there is NO guarantee that the LED won't overheat, or that the Laser driver chips / MOSFET's / PSU won't complain or explode at some point!

    Also, I wouldn't even think about plugging the laser ribbon back in after! There will not be any proper current regulation! (actually, it might even work, but it's very possible that all the laser diodes and / or projector will blow up).

    So far, my modded PJ seems to behave itself, but...

    I take absolutely NO RESPONSIBILITY for any damage to person, pride, property, or animals due to trying this mod!


    The first step is to bypass the two thermistors and the thermal cutoff on the laser block. I'm using small 0805 sized SMT resistors for this.
    All of the following mods are carried out on the LD / LED driver PCB...

    Here are the pinouts for the laser ribbon connector (30 pins on my A130's ??)...

    CN301 (Laser Diode bank conn - NOTE - Actually 30 pins, NOT 24 pins as labelled on the driver PCB!!!)...
    Pin 1 = THOF (Thermal cutoff) - 100 degree C, normally shorted to TMP-H (pin 5, 3.3V).
    Pin 2 = TH-L - Voltage divider for Thermistors (ie. "GND")...
    Pin 3 = TMP-1 - 10K Thermistor 1 on diode block (Spoof with 10K resistor!)
    Pin 4 = TMP-2 - 10K Thermistor 2 on diode block (Spoof with 10K resistor!)
    Pin 5 = TMP-H (3.3V for opposite pin of Thermal cutoff).
    Pin 6 = NC
    Pin 7 = Laser Diode Bank 1 Anode
    Pin 8 = Laser Diode Bank 1 Anode
    Pin 9 = Laser Diode Bank 1 Anode
    Pin 10 = Laser Diode Bank 1 Cathode
    Pin 11 = Laser Diode Bank 1 Cathode
    Pin 12 = Laser Diode Bank 1 Cathode
    Pin 13 = Laser Diode Bank 2 Anode
    Pin 14 = Laser Diode Bank 2 Anode
    Pin 15 = Laser Diode Bank 2 Anode
    Pin 16 = Laser Diode Bank 2 Cathode
    Pin 17 = Laser Diode Bank 2 Cathode
    Pin 18 = Laser Diode Bank 2 Cathode
    Pin 19 = Laser Diode Bank 3 Anode
    Pin 20 = Laser Diode Bank 3 Anode
    Pin 21 = Laser Diode Bank 3 Anode
    Pin 22 = Laser Diode Bank 3 Cathode
    Pin 23 = Laser Diode Bank 3 Cathode
    Pin 24 = Laser Diode Bank 3 Cathode
    Pin 25 = Laser Diode Bank 4 Anode
    Pin 26 = Laser Diode Bank 4 Anode
    Pin 27 = Laser Diode Bank 4 Anode
    Pin 28 = Laser Diode Bank 4 Cathode
    Pin 29 = Laser Diode Bank 4 Cathode
    Pin 30 = Laser Diode Bank 4 Cathode

    You don't need to worry about the Laser Diode connections, we will be bypassing this elsewhere.

    On the underside of the board, you can see the labelled test pads for the cutoff signals.
    First, solder a 10K resistor between the TH-L and TMP2 pads. These should be close enough together to solder the resistor directly between them.

    The other 10K resistor of course goes between TH-L and TMP1...
    To save using a wire link, you can just solder one end of the resistor to the TMP1 pad, then carefully solder the other end to the closest side of L305 (this inductor is connected to TH-L anyway).

    Then you need to bypass the thermal cutoff switch. This is normally closed, but opens when the laser block reaches 100 degrees C...
    You can simply join the THOF pad to the TMP-H pad with a wire link.
    Or, if it makes things a bit easier, you can solder one end of the wire to the THOF pad, then the other end to pin 6 of the white connector (CN207).

    OK, now comes the tricky part. (if you thought the above part was difficult enough, you're not going to like this very much )...

    You need to remove the four resistors R366, R367, R368, R369 next to IC300.
    These four resistors normally connect the amplified "laser current sense" outputs from IC300 to the processor (IC112).

    Then, what we're doing is taking ONE of the outputs from DAC chip IC110 (which outputs the current control signals which go TO the laser driver chips),
    and looping it back to the processor (IC112) to fool it into thinking everything is normal...

    Here are the relevant output pins from DAC IC110...

    IC110 (M62364GP) 8bit, 8 channel DAC - Used to control the current for each LD bank.
    The OUTPUTS (TO each LD driver) are...
    Pin 2 (Vout1) TO IC304 pin 16 (CTRL) = LD bank 1 current control
    Pin 3 (Vout2) TO IC303 pin 16 (CTRL) = LD bank 2 current control
    Pin 10 (Vout3) TO IC306 pin 16 (CTRL) = LD bank 3 current control
    Pin 11 (Vout4) TO IC305 pin 16 (CTRL) = LD bank 4 current control


    And here are the relevant input pins on processor IC112...

    IC112 (R5F212CASNFP 16bit MPU)...
    Current sensing...
    Pin 63 (Analog) FROM IC300 pin 1 (LD bank 1 current sense) via R368 <- Note: I've swapped the pin order here so LD bank 1 is first!!
    Pin 62 (Analog) FROM IC300 pin 7 (LD bank 2 current sense) via R369
    Pin 64 (Analog) FROM IC300 pin 8 (LD bank 3 current sense) via R367
    Pin 65 (Analog) FROM IC300 pin 14 (LD bank 4 current sense) via R366

    Voltage sensing...
    Pin 58 (Analog) FROM LD bank 1 Anode (via R112)
    Pin 59 (Analog) FROM LD bank 2 Anode (via R111)
    Pin 60 (Analog) FROM LD bank 3 Anode (via R110)
    Pin 61 (Analog) FROM LD bank 4 Anode (via R109)


    The "current control" output voltage from IC110 is close enough to what IC112 expects to see on it's "current sense" inputs,
    so we can just take the pin 2 (Vout1) output from IC110 and connect it directly to pins 62-65 on IC112...

    You COULD attempt soldering one side of the pads where you removed R366-R369, as these connect directly to pins 62-65 of IC112, but I did it another way...

    Basically, each of the "current sense" / "voltage sense" pins on IC112 have a small capacitor on them which then connect to Ground (for smoothing I guess)...

    These are caps C125, C127, C128, C130 for "current sense" pins 62-65 respectively.

    And caps C120, C121, C123, C124 for the "voltage sense" pins 58-61 respectively.


    The ends of each cap pointing TOWARDS IC112 are what we're interested in - the outside ends of the caps all connect to Ground!


    So instead of trying to solder directly to the pins of IC112, what I did is to use a VERY small single strand of wire to connect one side of C125, C127, C128, and C130 together.

    Then, use a wire link to connect from pin 2 (Vout1) of IC110 to your new wire bridge between pins 62, 63, 64, 65 of IC112.
    That should be the current sensing bypassed!

    (btw, I found it easier to solder to the pad of the missing R187 instead of soldering directly to pin 2 of IC110. You should be able to see which side pin 2 connects to.)


    The voltage sensing was a bit more involved. You see, the processor expects the voltage on these pins to be slightly lower than for the current sense signals. I tried connecting them directly but it didn't work (PJ shut down)...

    You need to first connect pins 58, 59, 60, 61 of IC112 together (again using a strand of wire to connect one end of C120, C121, C123, then across to C124).

    Then we need to form a voltage divider using two resistors to drop the voltage slightly...

    First, I soldered a 390 OHM resistor between the wire bridge on the "current sense" caps and the wire bridge on the "voltage sense" caps.

    Then solder a 1K resistor between the "voltage sense" caps and Ground (you can solder directly in parallel with C121 for example).

    I think that pretty much covers it. There may be differences between projectors, so I can't guarantee that this will work for everyone.
    Again, this mod has only been tried on ONE A130!

    If your PJ keeps cutting out (turning off), you might need to play around with different resistor values for the voltage divider.

    If you also want to bypass the door-switch, just solder a blob across the pins of CN901 on the main board (should be labelled "COVER").
    It goes without saying that you should watch out for the mains voltages in the power supply though!

    I will try my best to get some photos up soon, plus a decent photo of the driver PCB with the mod sections labelled.


    More soon,
    OzOnE.
    Last edited by OzOnE; 12-12-2011 at 22:26.
    "It's like lasing a stick of Dynamite."...
    http://www.youtube.com/watch?v=0ds0wYpc1eM&fmt=18
    Surely all PL members have seen this movie?

  3. #213
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    For some background info on the mod, here are some o'scope captures...








    These captures were taken from an A130 using 22 OHM power resistors instead of any laser diodes! I don't have any diodes to test, so real-world results will differ.

    The first image shows the current control outputs, the actual LD current (across the sense resistors), and the current feedback voltage for each ECO mode.

    The second image shows the actual laser bank voltage vs the voltage sense feedback signal for each ECO mode.

    The third image shows a composite of the laser bank current sense feedback (blue trace), the Red Phlatlight Enable pin (red trace), and the Colour Wheel Index signal CIDX (yellow trace). Note - this image was stitched together from separate captures!


    You can see where the laser bank is dimmed slightly during the BLUE (clear) phase of the colour wheel. Projectors generally need far more Green light than any other colour to produce white (as most of you will know ), so the trace is much wider for the GREEN phase.

    I don't think the Red LED actually pulses like that in reality, but that's the signal I got from the Enable pin of the LED driver chip?

    Note: With the mod in place, you can see the "current control" output from IC110 is still quite high when the "current sense" input would normally be near zero (ie. before the mod). The "current control" outputs only differ by the small amount that the current changes between the GREEN phase and BLUE phase - the real current output is controlled by a combination of this signal AND the LD Enable signals - the processor doesn't seem to care though (it only monitors the current feedback signal when the ENABLE outputs are high).

    For the voltage sense signal, it's almost the same waveform as the current control output, just that the overall offset is slightly lower (hence the resistor divider).

    btw, I haven't bypassed the colour wheel yet. You'd need to tap into the PWM signal to the colour wheel motor drive chip (PMD1000 / IC803) then generate the CIDX signal from that.

    To add the Green and Blue LED's, you'd need some extra drivers (obviously) then could do something like this...

    Wait for FALLING edge of the Colour Wheel signal CIDX -> Turn off GREEN LED, Turn on BLUE LED...
    Wait for RISING edge of Red LED Enable -> Turn off BLUE LED, turn on RED LED...
    Wait for RISING edge of LD "current control" -> Turn off RED LED, turn on GREEN LED.

    The CIDX signal is on pin 5 of CN905 (ribbon connector on main board).
    I think the Red LED Enable signal is on pin 1 of the Lattice chip (IC202).
    And you could use the "current control" output from pin 2 of IC110 (or any of the other three outputs) for the other signal. EDIT: Actually, maybe the Enable signal for the LD drivers would be better, as it should go down to zero volts when the lasers are off.


    OzOnE.
    Last edited by OzOnE; 12-13-2011 at 00:26.
    "It's like lasing a stick of Dynamite."...
    http://www.youtube.com/watch?v=0ds0wYpc1eM&fmt=18
    Surely all PL members have seen this movie?

  4. #214
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    ohhhhhhhhhhhhhhhhhhhhhhhhhhhhhh man...thank you thank you thank you thank you!!=) i gott enough here to keep me busy for the next 6 months!
    Now this is what i call DATA!!

    my hats off to you ozone!....and yes please post some pictures or video of it working..

    does anyone know how drastically the A130 differs from the A140?

    Keith.

  5. #215
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    Thanks, Keith,

    Here's some close-ups of the mod. It's not very pretty, and I made a few mistakes myself (a few of the caps are missing, so I bridged across pins 58,59,60 of IC112 instead.

    I thought I'd leave them on imageshack, so they don't screw up the thread. I not much of an artist, but here goes...

    http://imageshack.us/g/17/a130laserlessmodozone13.jpg/

    I'll repeat some of the instruction here for clarity...

    In the first image, you need to bridge across where I've drawn the thin wires (bridge across ONE end of each RED cap, then bridge across one end of each YELLOW cap).
    The "bits at the end" which connect to thin air just show the cap Ground connections.

    The "current sense" caps are marked in RED (C125, C127, C128, C130).
    The 390 OHM resistor is marked in MAGENTA and connects from the "current sense" wire bridge (RED) to the "voltage sense" wire bridge (YELLOW).

    The "voltage sense" caps are marked in YELLOW (C120, C121, C123, then stretch the strand of wire across to C124).
    The 1K resistor is marked in CYAN and connects from the "voltage sense" wire bridge to Ground (you can solder it in parallel with any of the "voltage sense" caps).

    The GREY wire then connects the "current sense" wire bridge to pin 2 of IC110 (I've soldered it to the right-hand pad of R187 instead).

    Then remove resistors R369, R368, R366, R367 marked in ORANGE. (This disconnects the original "current sense" signals from processor IC112).


    In the second image, you can see where I've soldered one 10K resistor (RED) directly between the TMP2 and TH-L pads.

    The other 10K resistor (also RED) can be soldered diagonally between TMP1 and the right-hand end of inductor L305.
    (Actually, this inductor simply connects TH-L to Ground anyway.)

    The THOF pad needs to be connected to 3.3V to bypass the thermal cutoff switch...
    You can either connect THOF directly to TMP-H with a short wire link, or from THOF to pin 6 of connector CN207 (also 3.3V).

    That's it!

    Hopefully this will work with most A130's. I wouldn't have thought the A140 is much different, but the resistor divider values may need tweaking?


    For future experiments with RGB LEDs , you could connect some extra wires to the Phlatlight and Laser Bank ENABLE signals...

    Note: I was wrong about the Red Phlatlight ENABLE pin in my previous posts.
    EDIT: I've re-uploaded the photo to correct this.

    The Phlatlight Enable signal actually comes from the processor...

    IC112 (R5F212CASNFP 16bit MPU)...
    Pin 8 TO Red LED driver (IC410) pin 11 ENable! (via transistors Q401 / Q402 and filtered by C427)


    The RED wire in the photo is actually the ENABLE signal for the Laser Bank 1 driver chip!...

    IC202 - Lattice CPLD...
    PWM outputs (TO each LD driver)...
    Pin 1 (PWM) TO IC304 via R357 = LD bank 1 PWM / Enable
    Pin 3 (PWM) TO IC303 via R354 = LD bank 2 PWM / Enable
    Pin 5 (PWM) TO IC306 via R363 = LD bank 3 PWM / Enable
    Pin 7 (PWM) TO IC305 via R360 = LD bank 4 PWM / Enable


    btw, if you want to try lowering the fan speeds, here is a graph of your typical 10K thermistor...

    http://www.medteq.info/med/files/Image/NTC10k.png

    If you use 10K resistors for the thermistor bypass, the processor will think the laser block is around 25 degrees C...
    You could try slightly higher resistor values of around 12K-14K to see if the fans slow down.

    Again, I'm not sure how this will effect the cooling of the Red Phlatlight!
    The Phlatlight will still have it's temperature feedback, so it should be OK assuming it's own fan is regulated??

    OzOnE.
    P.S. There may be a very simple and cheap way to generate the separate R/G/B enable signals. brb
    Last edited by OzOnE; 12-13-2011 at 11:08.
    "It's like lasing a stick of Dynamite."...
    http://www.youtube.com/watch?v=0ds0wYpc1eM&fmt=18
    Surely all PL members have seen this movie?

  6. #216
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    Very impressive! I hadn't thought of connecting the current control line back into the current setpoint line, that is quite clever!

    You should be able to tap into the green/blue signals directly from the DLP controller, they are called
    name - pin - function
    LED_RED_EN F28 Red LED
    LED_GRN_EN E27 Green LED
    LED_BLU_EN F27 Blue LED

    The question would be whether or not those pins are routed out, I have attached the relevant section of the xray I posted in the info thread, with red/green/blue dots where I think the pads should be. I may be mistaken, but I think I have the image rotated/fliped so that it matches up with the drawing in the data sheet. (http://www.ti.com/lit/ds/symlink/dlpc200.pdf)

    Click image for larger version. 

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  7. #217
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    I hadn't thought of connecting the current control line back into the current setpoint line, that is quite clever!
    Well I thought about forcing the LED driver and PSU on, but the Phlatlight wouldn't then be sequenced properly. This way, it drives the LED as normal and keeps the main board happy too.

    I also noticed the LED outputs in the datasheet, but I'm not sure if they will be driven at the same time?

    The chipset seems to have the option to either use the LED outputs directly, or drive a colour sequencer via a serial bus (like the Ca$io driver PCB).

    It would be interesting to see if the pins are driven - no idea how they are routed though?

    I tried simulating the simple RGB switcher earlier..

    It's just a cheap 4017 decade counter - The Colour Wheel Index signal resets the counter to 0 (turns on BLUE LED), then either LD or Phlatlight Enable signal increments the counter to turn on the RED then the GREEN LED.

    Unfortunately it only works if there are small gaps between the LD Enable and Phlatlight Enable signals.

    http://imageshack.us/photo/my-images...witcheroz.jpg/

    So, it would be far easier just to use a small AVR chip instead.
    You could use the AVR chip to simulate the CIDX signal too (so the colour wheel can be removed).

    I'll try bypassing the colour (phosphor) wheel next...
    The CW-PWM signal can be found just below the big DDP chip on the main board. You'd need to filter this into a voltage, or sample it with the AVR, then generate the CIDX signal in a speed range that the chipset expects.

    OzOnE.
    P.S. I'll try to get a video of the GREEN A130 up soon.
    The LED heatsink does get very warm though - the voltage drop of the Green Phlatlight is quite a bit higher than the Red, so instead of around 24W, the PSU dissipates closer to 40W!! It's been working so far, but it's possible it will damage the PSU or driver board soon.
    "It's like lasing a stick of Dynamite."...
    http://www.youtube.com/watch?v=0ds0wYpc1eM&fmt=18
    Surely all PL members have seen this movie?

  8. #218
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    now what exactly does this yield?..what i mean what is the finish product of this mod?...(i know this may be stupid question but i have to admit im just alittle lost (DATA OVERLOAD WARNING SNORGSFLAB DATA OVERLOAD!)

  9. #219
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    Firstly, there are quite a few people who have shown interest in using the DMD in these projectors for holography etc.

    Also there should hopefully be many of these projectors available for some time to come (minus the laser diodes) and are cheap, so the other obvious motivation is to add the Blue and Green Phlatlight LED's to convert the projectors back to full colour working order - (I thought that's what you wanted, kobra? )

    The above posts are purely to get the projector working with just the Red Phlatlight, but without needing the large (and very HOT) power resistors. The next step is to add the Blue and Green LEDs. I actually already bought some Blue and Green Phlatlights...

    Believe me, it's really not worth the effort trying to re-invent these Phlatlights by using cheap eBay LEDs - been there, tried that. (It would be difficult to get decent brightness as well as full colour operation in this way).

    These PJs should be quite well optimized for the Phlatlights, and they're really not too expensive now. Add the fact that there should be many spare heatsinks and lenses available and it's a no-brainer for anyone wanting to try RGB (imho). With the laser block removed, there is also plenty of space to add the Blue and Green LED + heatsinks + optics.

    I just need to bypass the colour wheel then force two extra Ca$io driver boards to drive the Blue and Green Phlatlights. Or, find or create a smaller PCB to drive both LEDs.
    After that point, the optics shouldn't be too difficult (just need the correct dichroics and figure out where to position the heatsinks).

    The final reason is - it's fun!

    OzOnE.
    "It's like lasing a stick of Dynamite."...
    http://www.youtube.com/watch?v=0ds0wYpc1eM&fmt=18
    Surely all PL members have seen this movie?

  10. #220
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    oh ok i got my bearings now ..yes i do want to get my projos fully operational...ive been hunting data on this thing so long that sometimes it gets jumbled in my brain (severe insomnia doesn't help)...

    how much did your blue and green phlatlights cost? and what are there specs?...especially the output of the blue one...does each color need to be equal in lumens? like 2300 lumens divded by 3 equals 766.66 lumens for each color (thinking of it in a linear fashion)..but will a blue led of say for example 300 lumens be enough? ...yeah i know fuzzy kinda question..
    have you plotted out the DMD color change rate/freq/pattern from red to green to blue yet? (not sure how its measured)


    great work man...and thanks for posting everything.


    Keith.

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