NC1000 ERROR - "586: IMB: Service Door Tamper" - non conclusive.

[James Gardiner]

I had an NC1000C stop during a show this morning with the following error:

Error: 586 – IMB: Service Door Tamper

We have exercised all known tamper switches and reseated the IMB2000 (it re-married successfully). We have specifically checked the tamper switch behind the front cover / lid.

We also attempted to clear the tamper using the special button sequence, however the error will not clear.

My question is: shouldn’t there also be an indication of which tamper switch is not closing? At present, we are only seeing the generic 586 error.

Is it possible this fault is originating from the IMB itself, rather than a physical door or microswitch?

My main concern is that I may need to bring in an engineer. However, I’ve already shown this to the most experienced engineers in our region, and there is uncertainty around both the root cause and what spare parts might be required. This is a 4-hour drive each way, so it’s important to be confident about the likely failure point and to bring the correct spares.

Any advice or guidance would be greatly appreciated.

[Ioannis Syrogiannis]

Not having experience with that model, I am just exercising logic here:

If it's not a cinema technician (or someone with relevant experience, if we want to be more inclusive) that did all troubleshooting, is there a chance that the steps were not followed to the letter, the facts (like the tamper switch working well) were not verified the way they should?

It seems to me that 586 is clear enough on which switch is open.
Did you (plural) try to bind the microswitch with some tape, or something, so it stays closed no matter what?
The problem may be further in, and not on the switch itself, admittedly.

I suppose that by IMB2000 you mean Dolby IMS2000. (?) It's not probable that the specific problem comes from there, but did you get any analytical diagnostics to upload to Dolby?

Maybe I should have wrote that first. But probably you did so when reseating the board. Yet, did you try to turn off the server and then the projector, and let the system with no power at all for a minute or two, before rebooting and trying again?

[Fraser Falconer]

Hi James,

Firstly, Unlikely to be the IMB. A Quick server swap if there are more than a single screen on site will quickly prove this.

The Service Door switches on the NC900/1000 of which there are 3, When they fault like this they are best to be replaced. The log will tell you which switch is activated, usually by a suffix. 0,1 or 2 in this situation.
There has been other threads that have discussed the tamper switch failures across all vendors, due to the low voltage and current running through the tamper switch circuits, coupled with a bit of tarnishing of the contacts etc. The NC900/1000 switches are essentially sealed and don't generally recover with the use of contact cleaner or De-Oxit. I will replace all the switches if called to a machine with these issues including the marriage tamper switches, which isn't a fun job.( they are all the same age and not super expensive, just the time to change them) I would recommend the Service tech comes prepared for a full switch replacement.

Cheers Fraser

[James Gardiner]

I have walked the staff doing basic dismantle, remove IMS2000 exercise switch, put back together, take top of, take front off. Put back together.
Run them through the button sequence to clear tamper, bother hold menu, and hold left/right arrow keys.

I have had a look at the logs, and there is "NO" indication of which switches is holding open. So, no info on exactly which switch to specifically try and get working again.
The site is 3-4 h each way drive. So I would prefer we KNOW exactly what is causing the fault before a 8h round trip is started.

I will try the IMS diags as suggested.

https://loganalyzer.dolbycustomer.com/index.php/reports/analyze/483922/2495a71281565efd8c418dacc14aedc3

I few issues, the disk not being supported is strange, Those disks came with the unit. It seems one is not supported. No idea how that happened. But not an issue.
A few issues based on the error occurring. It does look like the Player may be enforcing the error based on what I am seeing.
Anyone seen this type of error before?

[Steve Guttag]

The invalid boot sequence is nearly always due to an improper shutdown (power killed rather than waiting for a proper shutdown.

The HMDI EDID thing is interesting and not one I've seen before. I would update the software (looks like a hot fix) and firmware to current to see if that addresses it.

The crux of the issue still seems to be projector in origination. The projector is telling the server, which is the Security Manager, since it is an IMB) to shut the show down due to a service door tamper.

NEC uses all three wires on their cover switches. So, it is possible for a normally closed switch to open on that terminal without closing on the Normally Open terminal (and vice-versa). That is why switch replacement is recommended when they start acting up. They can half-work. I suppose this condition could explain the lack of switch identification. It may be using one terminal to indicate an open and the other terminal to indicate which switch it is. For instance, if they bussed the door tampers...any of the three could trip it. Let's say that is the terminal that is "noisy" and causing a false tamper. Yet, the other terminal is happily showing "no problem here," so no switch number. I'm not saying that is how they are doing it but that is a plausible scenario that could cause that situation.

[Leo Enticknap]

Annoyingly, error 586 doesn't give you a figure in parentheses to indicate which switch the projector thinks is causing the problem:

image.png
So I'm afraid that Fraser's and Steve's solution is the one that is most likely to be the fix. There are three switches to replace in total:

image.png

The absolute pigf****r is the "Internal bottom" switch, which is not only on the bottom, but at the very back of the card cage. A lot of fiddly disassembly is needed to get at it, including the complete removal of the card cage assembly.

[Ioannis Syrogiannis]

Those discs came with the unit, but the unit came from...?
I am wondering because, besides the one disc being another kind, all discs have different hours working.
In any case, all the best, for this New Year's eve adventure.

[Volkan Sezer]

Hello, for the NC1000C you need to enter a special menu settings screen and reset the IMB. Doing this should resolve the error. To do this, you need service passwords, which I cannot provide here.

[Leo Enticknap]

In the original post, James wrote that "We have exercised all known tamper switches and reseated the IMB2000 (it re-married successfully)" (my emphasis). I took that to mean that James knows about the secondary tamper clear procedure for the option slot, that was introduced with the NC1000 but which is not needed for earlier Series 2 NECs, and had done it.

James - is this the case? The tamper clear procedure that should have been done (in this order) is:

1. Clear clear the service door tamper (push and hold MENU on the keypad until asked for a code, then enter it)
2. Perform the marriage procedure using the DCC app
3. Clear the IMB slot tamper (push and hold left and right arrows on the keypad until asked for a code, which is not the code used in step 1, then enter it)

If step 3 wasn't done, that would certainly explain why the IMB slot tamper won't go away. However, if the start of this problem was that a tamper error appeared spontaneously, without anything having been done to the projector, then in the absence of an obvious explanation (e.g. faceplate screws had heat cycled loose), one of those switches is likely failing, and the complete set of three should still be replaced.

[James Gardiner]

Update,
The unit had a cinema engineer try to rectify the problem. Was unable to. Tried a different IMS (A new GDC) problem did not go away, so does point to the projector.
Has taken projector to office (3.5 hour drive) as has no idea why this error will not clear.

I hear a lot of people say NEC is reliable kit. But I have 5, and I would not say they are reliable at all (For example, 5x lightengine/formatter board faults/replaced. 1 major cooling system fault not even worth fixing, projector - 7 years old NC1100L to recycling/tip, run at 35% expected 14 years out of it. Numerous interlock faults.). Excessive faults all over. (Apart from a NC1201 unit, only unit not to have failed so far, all 7-9 years old) Not happy.

[Steve Guttag]

I can only state my experiences with NEC and reliability hasn't been an issue. I've done a few prism swaps for one reason or another. Minimal cost to the client, as compared to the other two brands. The NC900C, when the lamps (made by Ushio) were in their earlier designs, would fail and take the ballast out with it. Since that was resolved, so have the ballast failures.

Without a doubt, in the xenon era, Christie has been my most problematic and has interrupted more shows/per unit. Their unexpected lamp offs are just killers and unnecessary. The 1-3KW ballast used in the CP2200 and CP4220 (and the CP2000ZX before it) really doesn't do well with 3KW lamps. They are my most failure prone ballasts (Sanrex). My number one Barco failure is the signal backplane (excluding the defective SST version of the 4K DMDs since they are made by TI). I suppose we are getting some CCBs now on Barco...one of the key failures is its internal router.

[James Gardiner]

@steve, yes, I am likely to go with Barco next time, if there is a next time. 2025 numbers are in and attendance is down in nearly all regions, in a year we were supposed to see a recovery. Now we have more reductions, likely due to Netflix buying WB. I must admit, I feel really deflated right now.

Anyway, S4 projector range (SP2K specifically). Wants has been the main source of faults in that series specifically?

[Leo Enticknap]

My experience, both as an operator and a service tech, has been as follows:

NEC: Significantly cheaper up front cost to buy the projector than Barco or Christie. The first generation Series 2s (1200, 2000, 3200, 3240) have tended to be very reliable if well maintained (specifically, air filters replaced regularly). The only consistent weakness I've noticed is the internal lamp ballast and igniter in the 1200s and 2000s: I've swapped out quite a few over the years. They are not that hard to swap out, though the part is quite pricey. The "table top" NECs, though, and especially the 900, are difficult and time consuming to work on if something goes wrong, ballast cards and formatter boards being a big failure risk once a projector passes the five year mark. Their laser projectors have generally been OK: the only consistent weaknesses I've noticed are the power supply modules in the 602 and the G09 laser diode card in the external light source unit of the 1040L (I've had to replace it three times in one unit since installation in 2017!). However, the basic principle remains: you pay for the cheaper up front purchase cost with the much higher labor cost of many parts replacements, compared to the equivalent repair in the equivalent Barco or Christie.

Barco - Significantly more expensive than NEC, and the last I knew, slightly more so than Christie. Their Series 2 and 3 models need more planned maintenance than their NEC equivalents (e.g. annual coolant flushes), but in my experience they last longer before major components start to fail, and most component swapouts take fewer labor hours to accomplish. They are also, I would argue, a more viable proposition than NEC for an owner who is looking to self maintain, especially if installed in a location that is a long way from the nearest certified tech. Agreed with Steve that the backplanes are a weak point, though, and they are not easy to replace. Even then, most of the backplanes I've replaced have been in projectors that have been poorly maintained, with dirty filters and impeded airflow. Series 4 Barcos are designed to be maintenance free apart from annual air filter cleaning, software updates, and certificate battery replacement on the ICMP or ICP-D every four years. By and large, this has proven to be true. Last fall I was called to do a PM on a 10-plex of SP4Ks that we installed during covid. They'd all been running 10-12 hours a day, seven days a week since the spring of 2021, and they were all still OK (albeit with gross and disgusting air filters). The first generation of light engine on early Series 4s was a known weak point (stuck pixels), but this was largely fixed in a redesign, and those light engines are not shipping in Barco projectors sold now.

Christie - I have significantly less experience with these and have none among my service contract customers, so I don't feel qualified to comment on their general reliability versus Barco and NEC. I have swapped out maybe half a dozen lamp power supplies and/or igniters over the years, but those were all in decade-old machines.

[Steve Guttag]

I have already done multiple swaps on S4 signal backplanes. The scariest part is the SAS connectors that protrude into the light engine compartment are surface mount and easily decapitated. Without a doubt, Barco is far and away the easiest to service. Things are laid out logically and most things are on the "outside" layer of the projector. you don't have to "dig in" to get to a part. A notable exception is the signal backplane, of course. It is faster to change an S4 than an S2 (FAR fewer connections) but you still have to dig in a little. As for reliability, they've been pretty good though I've changed a few Laser Driver Boards.

NEC takes the Japanese design philosophy that removing many assemblies to get to the one you want is fine. Anyone that has worked on Japanese equipment (it doesn't need to be NEC projectors...it could be cassette decks, amplifiers...whatever...you just need to resign yourself to the fact that to get to what you want, quite a bit will need to come out first. Another trait of Japanese design is to leave internal metal parts sharp. They don't break the edges of their metal parts so you can easily cut yourself handling it.

Christie started somewhere between the two and is getting better. On their S4 stuff, the problems of their xenon power and sensors are, seemingly gone. Their .69" S4 projectors are price competitive to Sharp/NEC so they should be worth considering unless you would have support issues in your area. Christie also has their 35,000lm model in their medium chassis whereas Barco bumps you into the big ("B") chassis so there is a notable price and physical size advantage to Christie, on that projector size. I have also been incredibly impressed with the Cinelife + projectors with the UHC Premium lenses. It has the most filmic look I've seen on a DCP projector. The colors look right, despite being a laser projector and the premium lens allows for better focus/pixel alignment on the edges. Christie is also, now, allowing for actual keystone adjustment (so be prepared for a hit in the final resolution). One can also electronically tweak the convergence, by color. Again, you aren't really moving pixels...you're morphing them, so there is a resolution hit, at least in the corner that you are tweaking.

My biggest complaint with the NEC/Sharp projectors are their image qualities. Their .69" stuff has horrible contrast (1600:1) and miserable lens control such that it doesn't hit its mark in the same place. The larger stuff (.98" and larger) do much better though their color is always "cold." They don't offer, to the best of my knowledge, a true RGB laser system anymore (they had one, but I don't know of anyone that used it). The NC-3541L (and the NC-2041L) is an RBB laser system, so a green phosphor wheel. It/they are a solid projector with a decent picture/performance. Contrast isn't the best...color isn't the best and lens shift range is the least of the three companies. And, talk about service. The NC-3541L has....54 fans. Think about that time/expense when it is time to change them.

Despite Barco having the stuck pixel problem due to the TI DMD design flaw in the TRP chips (as Leo noted, they are no longer shipping with those, and hence why the SP4K-C projectors were off the market for over a year, they are now with a more conventional SST type DMD), has the best bang-for-the-buck projector in the SP4K-C series, if one wants 4K. The option to use "B" lenses steps things up a bit as High Contrast lenses are in play plus if you use the "B" lenses, the amount of lens shift afforded is VERY impressive. I also like Barco's Scheimpflug (aka Bore Sight) adjustment is the best for getting corner-to-corner sharpness. The projectors are also very quiet. Do get the exhaust adapter with the SP4K-C...the projector has an unfortunate design such that the top of the projector is essentially open. You can spill a liquid (or your ceiling could give way to a leak) right into it. The exhaust adapter ships with the 8" flange plugged so the projector can exhaust into the room via vents on the sides of the adapter.

[Marco Giustini]

Another trait of Japanese design is to leave internal metal parts sharp. They don't break the edges of their metal parts so you can easily cut yourself handling it.

or cut one of the many flat cables going to the engine while removing it! Sigh!