HDMI projector flicker

[SteveB_NI]

Anyone please help me diagnose / eliminate the cause of this?

Our assembly hall projector has 849 hours on the lamp and has developed a noticeable flicker very occasionally. Basically you either one of the following very randomly:

1. Split second of a flicker & the speaker output from the projector pops

2. Split second of a flicker

3. Split second of a flicker, followed by an HDMI source input message being displayed

 

After all 3 the projector picture continues as before with no user input required.

 

There is a secondary HDMI port at the stage (which is what is being used). I've changed the HDMI cable and it seems to have minimised it happening as much but it is still happening. No one is standing near the cables / connectors at the time it happens so I can't blame a lose connection affected by touch.

 

HDMI cable is connected via USB-C hub to a MS Surface Pro 7

 

I'm thinking of running a long HDMI cable to another port on the 2nd input panel to check if the stage side adapter is the fault here. Also planning to try a different Surface - any other ideas? Annoyingly it seems to only appear after the projector has been on for a while so difficult to check it in operation!

 

Thanks

[SamanthaD]

How long is the cable run to the projector and are you running HDMI direct to the projector or converting it (say to CatX). Longer HDMI cables are usually active and rely on an amplifier at the device end to power it. If you're going through a faceplate and an adapter the device may not be giving enough power, or there might be a fluctuation in the power?

[FragglePete]

HDMI can be so picky when you start going over even as short as 5m, we introduced a shed load of Newline boards last year and had no end of issues with HDMI output on longer runs from the teacher desktop PC. Setting the CEC to 1.4 instead of 2.0 on the boards did help some, but we started using HDMI over Optical cables for the longer runs and the problems disappeared. Not cheap, but in terms of just getting them working and us not faffing around it just saved us a lot of time and money.

 

Pete

[Martinwonder]

Hi Pete,

 

Do you have any faceplates in between the Teachers PC and Newline Boards? Interested to know as we had the exact same issue on a new build of ours. Was a nightmare.

[psydii]

I cannot recommend the BlueStream kit highly enough.

 

https://www.blustream.co.uk/hdbaset-transmitters with their HDMI cables at either end and you will have no* problems.

 

They do AOCs to, but for along long run where you will be regularly connecting/disconnecting, the HDBaseT will be more robust/lower cost to mainatin, as you only have to replace the relatively short laptop-HDBaseT cable as and when it gets damaged.

 

 

*laptops be laptops, firmware, drivers, and cheap HDMI ports can all still give you a headache, but with bluestream cabling at either end, if the laptop and projector are ok, you will be blown away by the speed the image pops up when devices are connected.

 

If problems persist after putting in known good cabling, then you will need to consider that it might be a projector fault.

[Martinwonder]

Will definitely give them a shout. Thanks!