Film-Tech Forum ARCHIVE: Issue with Image in NEC NC2500S

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Posted by Roberto Simancas (Member # 8787) on 02-07-2017, 05:49 PM:

Hello everyone, I hope you're all having a great day. I got in touch with a new client that has a NC2500S witch after so many years is having it's first problem.

The technician that installed this is not in the country (I'm from Venezuela and not many technicians here).

The problem is that when they try to play something the image looks like this:

Like the poltergeist movie. The sound is fine, everything is fine is the image that looks like that.

I will be going to check everything in a couple of days, but could this be a problem with the connections terminal?

Thank you all for your help

Posted by Leslie Hartmier (Member # 7053) on 02-07-2017, 06:23 PM:

I'm sorry, is that the correct picture? I see a picture of an auditorium, but nothing poltergeisty.

Can you describe what we should be seeing?

Leslie

Posted by Roberto Simancas (Member # 8787) on 02-07-2017, 06:27 PM:

Hi, sorry. What i mean is like a TV without a signal, you see like rain. Like this

Posted by Leo Enticknap (Member # 534) on 02-07-2017, 07:46 PM:

Cinelink snow.

What I think this means is that the link encryption between the media block and the projector has failed. The problem could be in the projector, but it could also be in the media block.

The image data that goes from the media block to the projector's input board is encrypted by the media block, and then decrypted in the projector. The snow indicates that the projector is not able to decrypt it.

Firstly, has the server and/or media block recently had a software upgrade? Or have you swapped out the server and/or media block, and are now using a different one? If so, this could be the reason. If your projector can only cope with the older Cinelink II DS encryption and not the newer TLS method, then a media block that is sending it TLS-encrypted image data will cause the snow.

If the answer to that question is no, then if it were me, I'd proceed as follows.

1. If you haven't tried this already, hard reboot both the server/media block and the projector.

2. Check the server's logs for any media block errors.

3. Check the projector's logs for any link decryption errors.

If you do see link decryption errors and in the absence of any other likely cause, try replacing the pair of HD-SDI wires connecting the media block to the projector. If that doesn't work, you're probably looking at a hardware failure, either in the media block or the projector.

If the server has been powered down for an extended period of time, the media block's battery could have drained, and the media block lost its secure certificates. That would explain the error, and if this has happened, the media block will need to be returned to the manufacturer to have them reinstalled.

If you have another server/media block at your disposal that is known to work with another series 1 projector, you could try hooking that up to the suspect projector. If you get a picture, this suggests that the problem is in the original server. If you get the snow, it suggests that the problem is in the projector.

EDIT/AFTERTHOUGHT: Just re-read your post, and seen "the sound is fine." This does suggest to me a projector issue: if the media block had stopped working, presumably the AES audio would be out, too.

As with any troubleshooting exercise, the important thing is to start with evidence gathering. Did this fault just develop out of the blue - in other words, nothing changed in the way the equipment was being used - or did something out of the ordinary happen that could have caused it? A software upgrade installed in the server, someone dropped a heavy object onto the SDI wires trailing across the floor, a breaker tripped during a show and the projector had to be restarted, etc. etc.

Posted by Jim Cassedy (Member # 4115) on 02-07-2017, 11:45 PM:

I've got an NEC at one location that occasionally, at the start
of the first show of the day, will put up nothing but 'snow' as you
describe in your post.

On that machine, all you have to to is switch to another macro
and back or just push the same macro button your're on twice,
and picture comes back, no problem.

This is a very intermittent problem, and only happens maybe once
every two months, or less.

Have never been able to get an answer what causes this, but cycling
the macro button fixes it every time.

Posted by Leo Enticknap (Member # 534) on 02-07-2017, 11:51 PM:

Good point. On the 2500 we used to have, it would occasionally go completely dead on a gore board input. This would happen after the DCP server (DSS200/cat862) was completely stopped, then another DCP or playlist selected, then playback started. The sound would play, but the pix would just be black video. Sometimes selecting a non-gore board input on the projector (e.g. DVI or the scaler board) and then back to the gore board would restore the pix, presumably because that refreshed the encrypted link. However, sometimes that didn't work and a hard reboot of both the projector and server/media block had to be done.

I can't now remember what software versions were involved, except that the TI board was on 15.1, the projector was on whatever was the final firmware NEC published, and the same behavior persisted through several DSS200/cat862 updates.

Posted by Roberto Simancas (Member # 8787) on 02-08-2017, 03:05 AM:

Hello all. Well first thank you for taking the time to respond. Second, according to the projectionist nothing has changed, no software upgrade, no hardware change and no electrical issues had happened in the theater. This happened out of nowhere, everything was working fine for years.

My first idea was to change the HD-SDI cables. I will also try Jim's idea (thank you for that)

Also, the test patterns of the projector show perfectly with no problem.

Posted by Steve Guttag (Member # 268) on 02-08-2017, 05:46 AM:

Cinelink snow can come from several factors...including a certificate issue on the TI boards, the cinelink encryption on the mediablock, signal to the projector, communication to the projector.

Do you know what server you have and its firmware/software versions? Likewise, do you know the firmware/software versions of both the projector and the TI software? The last version of NEC software for that projector was 2.11 and the last TI software is 15.1. That said, 14.0 is a good TI software to have around. It can be handy for troubleshooting certificate issues. 14.0 is just before the GORE board/Glue cable nonsense. However it is after the expiring 3D nonsense. Loading it on can get a Cinelink issue to stop and from then one can do a certificate recovery to go up to 15.1, where you ultimately want to be for the best subtitle support.

Note, the NC2500 is not one of the projectors I've ever serviced from NEC so my advice is going to be limited to those problems that are common to all DLP series 1 projectors but this is a definitely a cinelink related issue which means it is upset with the security of your system, somewhere. I presume test patterns display normally?

Posted by Roberto Simancas (Member # 8787) on 02-08-2017, 06:42 AM:

Hi Steve, yes test pattern display normally. Right now I don't know which firmware version does the projector and the server have, but they haven't been updated in a while

Posted by Leo Enticknap (Member # 534) on 02-08-2017, 10:47 AM:

Thinking about this overnight, the other possibility that occurs to me is the data network in the booth.

With the Cinelink system, the media block sends the decryption link key to the projector using the booth's data network, not the HD-SDI cables through which the pix data travels. On a series 1 system working normally, try pulling the (auditorium) network cable from the server or projector. Even though the HD-SDI cables are still connected, the picture will disappear within seconds. So a network switch or router gone bad could be a possibility, especially if there is nothing else on that network besides the server/media block and projector to raise the alarm (e.g. you operate the server from a keyboard, mouse and monitor connected directly to it, and the projector from a touch panel).

That having been said, whenever I've experienced this, the screen has gone black, not to Cinelink snow, but it's still a possibility I'd be inclined to investigate.

Posted by Gordon McLeod (Member # 33) on 02-08-2017, 03:15 PM:

On the 2500 there is a internal router in the projector that is no longer available and i have had them go bad
in many cases it was the network switch was at fault and replacing it cured the repeated problem

Posted by Leo Enticknap (Member # 534) on 02-08-2017, 04:14 PM:

That should be easy to check, by pinging the projector from another device on the network: ideally the DCP server, because if the projector replies to the ping, you know that LAN connection between the two is good and can rule that out as the cause of the link decryption failure.

Posted by James Falloon (Member # 1933) on 02-08-2017, 09:36 PM:

Leo, Would it be better to ping the projector or ping the TI board directly?

Posted by Stephan Shelley (Member # 8587) on 02-08-2017, 10:51 PM:

By any chance was a software upgrade done to the server recently. If so it may be the issue. It may have changed it to Cinelink II TLS which not all series 1 interface boards are compatible with.

Posted by Leo Enticknap (Member # 534) on 02-08-2017, 11:34 PM:

The OP reports that no software update has been done immediately before the fault appeared, which would appear to rule out an undesired DS to TLS switch.

James - good point. So long since I've done any serious work on a series 1 machine (our smallest house still has one, but it's been months since I've run a show in it) that I forgot that the TI board has its own IP address.

If neither the projector nor the TI answers a ping, that would suggest a network problem, possibly with the projector's built-in router, as Gordon suggests (either that or the projector is completely buggered, especially if another device on the network does answer a ping from the server). If the projector answers but the TI doesn't, it would seem that you have a bad TI board. If the TI answers but the projector doesn't, then, unless the logs give you a lead, the next troubleshooting steps are well above my pay grade!

Posted by Roberto Simancas (Member # 8787) on 02-09-2017, 03:09 PM:

Hello to all, Ive tried with every solution you guys talked about (except installing the TI software 14.2) but Im getting this error #26 tamper switch activated detected. Could,this error affect the image like that?

Posted by Stephan Shelley (Member # 8587) on 02-09-2017, 03:43 PM:

It will. You might have a micro switch going bad. Will let others that know more about series 1 NECs answer. Not sure if you clear a service door tamper the same way as series 2s NECs.

Posted by Steve Guttag (Member # 268) on 02-09-2017, 04:24 PM:

If you do go to TI 14...go to 14.0. That is the "magic" one.

A service tamper is exactly what will set off a problem like this.

It looks like Error 26 is a rather broad error. NEC starts with making sure all three of the TI boards are well seated. Then check the voltages on the PJDIV board and it ends up with making sure no switches are tripped. They also say to check the settings on the titles to make sure everything that is supposed to be there is there (e.g. MCGD, PCF and so forth).

Posted by Leo Enticknap (Member # 534) on 02-09-2017, 11:00 PM:

That explains it, alright.

The secure input board (gore board) won't work if a tamper has been detected - in other words, one of the front or side panels is open, and/or, as Stephan suggests, one of the microswitches that detects whether the panels are open or closed has actually gone bad. This is anti-piracy paranoia - they don't want the unit to be able to decrypt DCP content with anything open, to prevent you from being able to hack into the signal path and steal the decrypted content.

So alternative content and all non-gore board stuff will work, but Cinelink decryption for DCP content will not, hence the snow.

I can't remember how you clear a tamper error (once the hardware problem has been fixed, e.g. removing and refixing the front, top and side panels) on a series 1 NEC. On a series 2 you press and hold menu for a few seconds and then enter the service code, but I think it's different on their series 1 machines.

Posted by Roberto Simancas (Member # 8787) on 02-10-2017, 01:07 PM:

Hello, well the problem was with a switch, the one under the connections terminal. one of the cables was broken right on the switch. Soldered it and problem fixed.

The error was gone after I rebooted the projector.

Posted by Mark Gulbrandsen (Member # 72) on 02-10-2017, 02:06 PM:

Series 1 doesn't have a router per say. Probably a small network switch down in the pedestal at most like Christie did. And I have had a number of network switches drop dead recently!! 4 to 7 years is about it out of one of those!!

Mark

Posted by Gordon McLeod (Member # 33) on 02-10-2017, 04:12 PM:

Wrong Mark there is a router on the main board

Posted by Mark Gulbrandsen (Member # 72) on 02-10-2017, 07:49 PM:

At least they did it right then....