Friday, October 12, 2012

Nikon D2H/D2X shutter circuit and operating procedure

Nikon D2H/X shutter unit


This article is written by the me in my spare time. Donations would be greatly appreciated. Please consider donating to the BitCoin address below.

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    Well, my D2H's shutter died at shutter count #49985, after showing 3+ years of annoying Err message, and the rear curtain shattered. The I bought a shutter unit of D2X (used part), and... Long story short, it's alive~~~~ Now, another 50k or 100k shutter life?

    I dig into the broken shutter. Ok, when you look into the F-mount of a D2, there're 4 gray shutter blades behind the mirror, which is the front curtain.

    Wanna see the Rear curtain? Not that simple. Normally, when a shot fired, the camera charges the shutter immediately. There's a way, use M mode, set to bulb, press the shutter button and hold your finger down, pull out the battery, lift the mirror carefully, then you will see the black rear blades, also 4 of them. Insert the battery, the top LCD will blink "Err". Relax, this is quite ok and harmless. Just press the shutter button, D2 will charge the shutter.

    Let's talk about circuit. There's a FPC connecting the shutter and body electronics. On the shutter, are 4 capacitors, 2 solenoid, 1 SOT23-5 device(dual NPN transistor with integrated resistors), and a gold plated leaf switch connected via 2 PVC wires, one green one red. The FPC connector, has 6 contacts, from left(according the photo) to right, i call then pin 1 to 6. The pinout is: 1:SW-FC, 2:V+(most likely 3.3~5V), 3:FC hold, 4:RC hold, 5:GND, 6:SW-RC. The switch is X-sync switch(shutter slower than 1/250s). When the FC open, this switch closes, that fires the flash, then the rear closes, a flashed photo is taken.

The schematics of FPC. R is about 20kohm, solenoid DCR 180ohm. (updated 20121016)

 

    Under the FPC, theres block of very complex mechanism with gears, springs, and levers. I'm a electronics engineer, don't know very well about that. But I know, the top lever with a bearing is the shutter charging lever, and the one at right side, near shutter blades, is shutter release lever.

Shutter unit detail


    That's it. The following is shutter operating steps:
    for shutter slower than 1/250s
  1. Shutter charged.
  2. Shutter button pressed
  3. pin 3, 4 goes high, FC and RC solenoid are powered. keeps both curtain from releasing.
  4. Electronics fires the mirror mechanism.
  5. Mirror lifted up, Shutter release lever is pressed by mirror mechanism.
  6. Shutter "safety off, ready to fire"
  7. pin 3 goes low, FC released,
  8. FC fully open (this takes about, let me guess, 3ms), SW_FC closes, flash fires
  9. Wait for time of shutter speed, for example 1/60s
  10. pin 4 goes low, RC release.
  11. 3ms later, RC fully closed, SW_RC close. if this time-out, "Err" message shows.
  12. Shutter charger pushes the charge lever, charges the shutter again, and mirror back down, both SW'es open.

for shutter faster than 1/250s

  1. Shutter charged.
  2. Shutter button pressed
  3. pin 3, 4 goes high, FC and RC solenoid are powered. keeps both curtain from releasing.
  4. Electronics fires the mirror mechanism.
  5. Mirror lifted up, Shutter release lever is pressed by mirror mechanism.
  6. Shutter "safety off, ready to fire"
  7. pin 3 goes low, FC released,
  8. Wait for time of shutter speed, for example T=1/1000s, 
  9. pin 4 goes low, RC release.
  10. FP flash fires, one pulse each time of T (or less). so the flash illuminates whole frame by multiple stripes, through the shutter gap. For FP sync detail, check http://www.scantips.com/lights/flashbasics2b.html and  http://www.photozone.de/hi-speed-flash-sync
  11. FC fully open, 3ms after FC released
  12. 3ms after RC released, RC fully closed, SW_RC close.
  13. Shutter charger pushes the charge lever, charges the shutter again, and mirror back down, both SW'es open.


  Thanks for reading!

3 comments:

  1. hola seme daño las cuchillas de disparo donde las puedo comprar

    ReplyDelete
  2. hola seme daño las cuchillas de disparo donde las puedo comprar

    ReplyDelete
    Replies
    1. I bought mine from taobao at about 500 RMB. Which they recycled from some damaged D2X. Seems these parts went extinct these days. Good luck!

      Delete