The projector here is an M260X NEC, manufactured in 2011. This was purchased in 20013, and has failed. On switching on, it beeps, the lamp would come on for 1 or 2 seconds, status light flashes once green, followed by 9 cycle red blinking status LED. Looking up the manuals, this is known as a 'dynamic contrast' error. There will also be a clicking noise as the motor tries to find a grip or position of the shutter/iris. Upon failing it will blink red, 9 times each cycle.

Dynamic contrast is used by the projector to darken the scene, to get richer blacks, it's active in a few modes, and can be turned off under, MENU, PICTURE, DETAILED SETTINGS. 

This projector is out of warranty and has about to my calculation 2000~hrs on the lamp. (When I got it working it was actually only 1600hrs) I figured it was not worth sending in for repair. I was quoted $40 for the Iris assembly, and $120 for the workmanship, quoted to me by the NEC service center in Singapore.

First time documenting a tearing down a consumer electronic device for repair. (Original fix was suggested on Fixya - link below)
You will need a small Philips head (+) screw driver for most of the work.

Make sure you get all the screws, I also removed all the feet of the projector.
One of the housing screw hides in the air filter area.

TIP: Unscrew the lamp cover as well. It has a micro switch, therefore, you may get an error if the cover isn't place via sliding it back in. If the top cover is just closed, the micro switch won't activate, giving a ONE BLINK error. So the last step is to slide back the lamp housing cover.

Gently pry open the casing, I find that it gives way easily from the filter side of things.
Do not force it open with much speed. The top cover is attached to the main board via the wire that leads to the lens cover sensor!

 Disconnect the sensor wire from the mainboard and remove from the cable loop/retainer. (I found this easier than removing from the sensor board)

Tada, the main board of the NEC M260X

I had to dig around some diagrams to see where to access the assembly. The main Fixya did not have any description.

When I Googled, 24B17981 I found a page with the schematic of this projector series

Link: http://mobilepro.ch/content/orders/NEC%20DISPLAY%20SOLUTIONS/pdf/MNNMFILTERSET.pdf

source: http://mobilepro.ch/content/orders/NEC%20DISPLAY%20SOLUTIONS/pdf/MNNMFILTERSET.pdf

To access the Iris you need to remove the main board. I decided to hinge it forward, by disconnecting the:
- LCD ribbon cables
- A few of the smaller cables towards the rear of the projector

Once the cables are undone, there are two screws at the sides of the IO panel / rear connector / input panel, that needs to be unscrew. (picture only shows one) Undo BOTH the left and right side. The entire board and rear IO panel should then flip forward. 

Have something for the main board to sit on, I just used the top cover to rest the main board so as not to strain any wires.

Next step: Remove the LAMP assembly. WARNING: Be careful not to touch any part of the bulb! like any halogen/pressure lamp source oils from your fingers can cause uneven expansion of the very very very hot lamp and blow it up. $371 in my country. 

You should see this once the main board is gone, and lamp is gone. It's a metal shield - BARRIER (LAMP) PBC0 24H69851; remove the two screws and remove it. This is located right next to where the lamp used to be housed. 

Once removed you will be able to access the Iris unit [ IRIS UNIT (PBC0) 24B17981]

Here is the offending clicker on start up.

Okay the fix:

I just move the blades back and forth a few times. And blew on the REFLECTIVE OPTICAL SENSOR, which in the fixya the guy describes as an octo-coupler. That's all I did an mine was back up working (so far).

Things you can try, maybe lightly grease the gears, NOT GUNK IT. 

Clean the sensor with isopropyl alcohol (at your own risk, should be safe)

Now once done and angry about a $40 part failing an $800 machine. Assemble everything back reverse order. 

NOTE: unless you defeat the micro switches, you need to replace all the covers for it to fire up.

Don't forget this little connector. It dropped in side and I forgot about it. Without this it gives me FOUR cycle red LED flashes. CPU/FAN/PSU error.

Have fun guys! (:

Original solution:
http://www.fixya.com/support/t16086633-nec_np_m300x_dynamic_contrast_error

Sources:
http://yourbusiness.azcentral.com/troubleshoot-nec-projector-beeps-14419.html
https://www.manualowl.com/m/NEC/NP-M300X/Manual/155046?page=124
http://mobilepro.ch/content/orders/NEC%20DISPLAY%20SOLUTIONS/pdf/MNNMFILTERSET.pdf

Tags:
9 blink status light, NEC projector error, Projector error NEC M260X; M260XG; beep code NEC projector; error code NEC projector; NEC status light blinking; NEC projector; Iris error; iris; 24B17981; Projector tear down; disassembly; DIY; Projector disassemble; repair; step by step repair; NP-M230X; M230XA; M260X; M300X; M260W