How is the change from projectors to display panels going as time goes on?

[Hoyt]

Howdy all,

 

In my district we just started migrating from overhead projectors with VGA cables to display panels a couple of years ago.  With the projectors they were drop dead simple with DisplayPort to VGA adapters.  When we started getting in some display panels of various brands (why on earth would they all be the same?) we used REI HDMI to Ethernet adapters.  None of them are above 1920 x 1080 so they seem to work for the most part, but occasionally we have to unplug the power supply to the REI box the PC is plugged into to get the PC to sync to the board again.  For the panels with touch we use USB to Ethernet adapters.  Those get a little weird with some brands (SMART in particular).  Oddly enough I have better luck with the SMART branded USB to Ethernet extenders I saved from the old SMART boards that these newer panels replaced.

 

How are y'all connecting to your display panels?  For the most part we have PCs with DisplayPort outputs (we have a few with HDMI but have had terrible luck with them) and convert that to HDMI over Ethernet as described above.  In some very rare cases the PC is close enough to the panel to run a direct cable.  We are an isolated rural district so we don't have many other folks to bounce ideas off of.

 

Also I have wondered about how we could handle things in the future when these panels go out of warranty.  It is a real time consuming pain to RMA one of these panels when it dies.  I can swap out a lamp in a projector in five minutes.  I can swap out the entire projector in fifteen.  Those are small and cheap things we can keep as spares.  Nobody in our org and tackled the idea of what to do when these large, heavy and expensive display panels start conking out after the warranty expires.  What do y'all do in those scenarios?

 

Thanks for reading this far.  Just trying to see what folks do in more modern areas.

[DrBeaker]

4 hours ago, Hoyt said:

...In my district we just started migrating from overhead projectors with VGA cables to display panels a couple of years ago.  With the projectors they were drop dead simple with DisplayPort to VGA adapters.  When we started getting in some display panels of various brands (why on earth would they all be the same?) we used REI HDMI to Ethernet adapters.  None of them are above 1920 x 1080 so they seem to work for the most part, but occasionally we have to unplug the power supply to the REI box the PC is plugged into to get the PC to sync to the board again.  For the panels with touch we use USB to Ethernet adapters.  Those get a little weird with some brands (SMART in particular).  Oddly enough I have better luck with the SMART branded USB to Ethernet extenders I saved from the old SMART boards that these newer panels replaced.

 

How are y'all connecting to your display panels?  For the most part we have PCs with DisplayPort outputs (we have a few with HDMI but have had terrible luck with them) and convert that to HDMI over Ethernet as described above.  In some very rare cases the PC is close enough to the panel to run a direct cable.  We are an isolated rural district so we don't have many other folks to bounce ideas off of....

 

 

VGA was 'old' ... yet it simply worked, every time.

 

DP/HDMI especially - finding it very fussy with connections.

 

Even worse with USB-C docks on laptops. Then staff can't figure out how to use them duplicated/extended etc.

 

 

Quote

...Also I have wondered about how we could handle things in the future when these panels go out of warranty.  It is a real time consuming pain to RMA one of these panels when it dies.  I can swap out a lamp in a projector in five minutes.  I can swap out the entire projector in fifteen.  Those are small and cheap things we can keep as spares.  Nobody in our org and tackled the idea of what to do when these large, heavy and expensive display panels start conking out after the warranty expires.  What do y'all do in those scenarios?...

 

 

Similar problems.

 

No-one has had the thought on any replacements / what to do etc. A lot are now coming to the end of their limited 'support' lifespan as is. 

[Rob_D]

Most of our rooms, we just run direct HDMI and USB into the classroom display screens with  HDMI and USB over ethernet in a few locations. HDMI over ethernet (kramer units) has been very reliable, USB over eithernet can be a bit twitchy.

We're on our second generation of display screens now, so keeping a few of the older ones back as drop-in replacements while the other ones are being RMAed has worked pretty well. It's not as easy as with a projector, but with the site team's help, we can swap out a board in about 10 minutes.

Although we've had a lot of problems with our most recent batch of boards, so we're looking at cycling them out again sooner rather than later.

 

 

[BenQ_Chris]

Hi @Hoyt the age old issue of tech moving forward but losing some of the simplicity.

 

USB-C is great, a single unified port, except it isn't, it's a standard interface but different ports have different capabilities, different cables have different specs and source devices don't always allow video out on all USB-C ports. The cable itself can be a minefield, we ship a 1.5m cable as standard. The longest standard cable I've seen is 3m. After that you are looking at some high end £100+ specialist cables. For us, we state you need a USB 3.2 gen 1 or better to get video, audio, data, power and touch.

 

As for HDMI, there's a little known industry issue now that all boards have gone to 4K/60; the GPUs (for the most part) can handle 4K/60 but often the HDMI ports are only HDMI 1.4 and can only handle 4K/30. This can lead to signal drop out. Many of the good boards on the market allow to change the EDID on the panel from 2.0 to 1.4 which caps the resolution the screen asks for to 4K/30. This can help resolve a lot of the issues. The other issue you have is cable length; for the most part HDMI will run 5m no problem, higher quality cable can go to 10m. But often you will need HDMI/LAN extenders. EDID 1.4 will typically give you a distance boost.

If you have any questions, happy to try and help.

 

Thanks, Chris

Senior Technical Sales Manager

BenQ UK

[MartinT]

We used USB to ethernet transceivers as it was the USB (touch) signal that suffered from the long runs.  Otherwise, HDMI runs up to 10m seemed to work well for nearly all the classrooms.

 

Training the teachers about Win-P to either extend or duplicate the displays took an inordinate amount of reminding.

 

Don't get me started on Macs, the bloody things just decided on the day whether they were going to drive the display or not.

 

As for keeping the displays young, a rolling replacement schedule saw us ramping up to replacing roughly a fifth on a five-year plan.  If you let them all age together, you'll be in a world of pain eventually.

[Hoyt]

Quote

We used USB to ethernet transceivers as it was the USB (touch) signal that suffered from the long runs.  Otherwise, HDMI runs up to 10m seemed to work well for nearly all the classrooms.

 

Training the teachers about Win-P to either extend or duplicate the displays took an inordinate amount of reminding.

 

We have a few long HDMI runs but have had problems with them depending on the panel brand/model so often fall back on the HDMI to Ethernet extenders.  Also since most of our PCs are the HP business class they tend to have DisplayPort outputs instead of HDMI.  We have some that have both but the HDMI ports have been dang near non functional.  SMART tech support actually told us to get DisplayPort to HDMI adapter dongles and sure enough that helped a great bit.

 

Fortunately our teachers have used projectors for over fifteen years and we had placed shortcuts to DisplaySwitch (a lot of my schools still say "Connect to a Projector" from the XP/Win7 days) on their redirected Desktops so they are used to navigating the different display modes.

 

Martin do you recall if y'all ever had to convert from DisplayPort to HDMI on any of those longer runs?  In some cases if the panel had a VGA input on it I just reused the VGA cable and those have been rock solid.  Nobody around here has gotten Shiny Object Syndrome (tm) for 4K resolutions, so that helps.  I haven't seen anything yet that wouldn't work just fine at 1920 x 1080.

 

Thanks for all the info it is good to hear from everyone.  Oh one thing I happened to remember; do y'all have a favorite USB over Ethernet extender?  The SMART branded units seem to be the most reliable of what we have tried but they are pretty expensive.  Some of the El Cheapo Monoprice units will transmit the touch signal, but often fail when it comes to actual data transmission (think SMART Ink functionality).

 

Thanks again for all the help.

[MartinT]

No, I never had to adapt DP as I only ever bought Lenovo mini PCs with HDMI ports.

 

I can't remember the USB to ethernet adapters we used, but they were good and we stuck with them. Others, as you say, tended to be flaky or just stop working. I'll try and find out what they were.

[thimon]

To help simply connecting to classroom screens, I’ve started to install USB hubs in each classroom. The HDMI and USB cables from the screen, plus a laptop charging cable (to allow pass through charging) go into the hub, with about a 1m USB C cable to connect to staff laptops. Reduces connecting 3 cables to laptops to 1, which staff are loving. £25 per hub, best investment for a while! 🙂

Edited November 18, 2025 by thimon

[MartinT]

I visited a school once that issued Microsoft Surface tablets to every teacher and installed a full dock in each classroom, connected to the display.  Superb, elegant, solution but it must have cost them a packet.

 

St Swithuns, Winchester, I seem to remember.

[localzuk]

We have specifically been buying screens with built in wireless tools. Specifically Iiyama's screens with their iishare stuff. This is replacing our use of Microsoft Wireless Display adapters. So, staff go to a room, press Win+K and choose their screen. No need for cables at all. Works with the interactive features as well.

[mavhc]

15 hours ago, thimon said:

To help simply connecting to classroom screens, I’ve started to install USB hubs in each classroom. The HDMI and USB cables from the screen, plus a laptop charging cable (to allow pass through charging) go into the hub, with about a 1m USB C cable to connect to staff laptops. Reduces connecting 3 cables to laptops to 1, which staff are loving. £25 per hub, best investment for a while! 🙂

which model did you get?

[BenQ_Chris]

One of the issues of using USB hubs is that it is possible to reach a USB tier limitation, depending on the chipset and mainboard used it may have already daisy chained several tiers internally. I have seen it where some panels don't even let you connect one USB hub as it hit the tier limit.

 

Thanks, Chris

Senior Technical Sales Manager

BenQ UK

[thimon]

We’ve got Promethean screens, which have their own wireless offering. However the laptops are sat on the teacher’s desk right next to the screen, wireless vs cable is a non starter when HDMI is much better quality and faster response for the touch element. We’ve been using the below USB hub with no problems across multiple departments. https://amzn.eu/d/iQ3iYie

[BenQ_Chris]

We have built in casting (InstaShare 2); but I agree with you @thimon, and I'll always say this to a customer, cabled is always better than wireless on a purely video/audio/touch quality and latency. Built casting definitely has its uses.

 

Thanks, Chris.

Senior Technical Sales Manager

BenQ UK

[thimon]

Just re read your other comment Chris, we’re connecting the hubs at the laptop end, not into the screens. Don’t know it that helps clarify. Cheers

[BenQ_Chris]

@thimon that's all OK then. I've seen straight USB hubs connected in to the screens and daisy chained 5 layers!

 

Thanks, Chris.

Senior Technical Sales Manager

BenQ UK

[SamanthaD]

22 hours ago, localzuk said:

We have specifically been buying screens with built in wireless tools. Specifically Iiyama's screens with their iishare stuff. This is replacing our use of Microsoft Wireless Display adapters. So, staff go to a room, press Win+K and choose their screen. No need for cables at all. Works with the interactive features as well.

 

We try to avoid this as we're worried about tying ourselves into a particular brand, then that brand changing into something we no longer want / need.

 

On 18/11/2025 at 13:55, Hoyt said:

Oh one thing I happened to remember; do y'all have a favorite USB over Ethernet extender?

 

We use extended Lindy USB cables, no adapters needed. Typically use a 15m cable to our interactive displays. Also the same for longer HDMI cables - Lindy or Van Damme HDMI's are pretty solid.

 

And if you want to delve into USB a little further I highly recommend the white paper Extron released at https://www.extron.com/article/understandingusbwp - including how not all USB-C connectors are born equal and what Chris was talking about regarding cascading hubs.

[drutt]

We've been using ViewSonic IFP7550s since 2019, we trickled a few in between 2018/19 then did a big £80k upgrade to all classrooms in summer 2020 after happy with testing.

 

Our staff typically connect via VCast which works really well, we've started removing cables from the screens so VCast is the only way to connect to simplify the transition and reduce confusion.

 

Before VCast we would use a StarTech dock to connect all the cables to so that the staff member only needed 1 USB cable for everything.

 

We've had about 5 screens (out of 40~) fail since then with the same fault, 3 were in warranty so got straight swaps and 2 more were callout repairs that cost no more than £200.

Edited November 20, 2025 by drutt

[psydii]

17 hours ago, BenQ_Chris said:

One of the issues of using USB hubs is that it is possible to reach a USB tier limitation, depending on the chipset and mainboard used it may have already daisy chained several tiers internally. I have seen it where some panels don't even let you connect one USB hub as it hit the tier limit.

 

Thanks, Chris

Senior Technical Sales Manager

BenQ UK

I've seen it where a hard reset (pin in the reset switch) of the laptop resolved the "too many hubs" error. Sometime just changing usb port on the laptop lets you work around it if a reboot isn't convenient. Anybody remember when end-user technical manuals were technical and had block diagrams for how things were really connected?

[psydii]

On 17/11/2025 at 20:16, DrBeaker said:

 

 

VGA was 'old' ... yet it simply worked, every time.

 

If you had wired-in desktops and well installed VGA, yes it would typically be more consistent that how things are done right now, but not always.  Cable quality, run length, and chipsets all could mess you up. I can't recall how many off colour, flickery images I've seen in the 20-ish years where VGA was king in classroom AV. It was generally more consistent in its failure modes. HDMI is much more prone to "working fine" until it suddenly doesn't, inconsistently.

 

But HDMI is a much more reliable medium for mobile teacher devices than VGA every was.  We are seeing a 0.2% failure* rate with HDMI (by helpdesk call volumes), with VGA it was closer to 1%, and swapping a HDMI is easier as we don't bother with inter-connects at the faceplates anymore. Of the rooms that have moved back to post 2021 usb-c docks, and post 2021 laptops, the failure rate is currently 0% (with insufficient data point to crow about that though).

 

*failure = call IT for help, but often resolved before we get there, and we see one cable needing to be replaced roughly every 2-3 weeks - which is why we're hopeful that  a return to usb-c docks with good quality USB-IF certified (but cheaper than 10m AOC) USBC cables is the future.

[psydii]

By the way, @Benq_Chris's presence here, saying publicly what IIyama people has have told me during support/project calls gives me great confidence in their (Benq's) products even though I have never used them. (IIyama are great by the way).

 

For us, having cabling that exceeds the capabilities of either end and the screens limiting themselves to 4K30 seems to be the secret sauce.

 

As for out-of-warranty replacements, I expect we'll have some sort of limited refurb of a few rooms (because there's always something happening every few years) - and use the funding from that to replace a % of the boards - putting the old ones into storage as spares. If post-warranty failure rates climb, then we just need to put in a replacement programme that slightly out-paces the failure rate, installing (purchased quantity - %failure rate) and holding the remainder as swap-stock util EoFY, at which point we order new batch install and hold a %  repeating  ad infinitum.

[mavhc]

So how do I automatically limit the benq screens to 30p?

[Hoyt]

Quote

One of the issues of using USB hubs is that it is possible to reach a USB tier limitation, depending on the chipset and mainboard used it may have already daisy chained several tiers internally. I have seen it where some panels don't even let you connect one USB hub as it hit the tier limit.

 

Couldn't have anything to do with the LED light strip the teacher plugged into the USB port of the panel could it?  Or the air freshener?

 

All joking aside we only use desktop PCs to plug into the panels, so some sort of cabling is what we would like to stick with.  Due to the layout of some rooms running Ethernet cable with converters was the first thing we thought of since we were doing the same for the HDMI connection.

 

Another thing I should mention is they empty out every classroom at the end of every school year to clean and wax the floors.  That is a huge stress on cabling so being able to just put three keystone jacks on a 2x4 box on the wall to plug everything back in was enticing to us.

[Gongalong]

On 17/11/2025 at 15:45, Hoyt said:

How are y'all connecting to your display panels?  For the most part we have PCs with DisplayPort outputs (we have a few with HDMI but have had terrible luck with them) and convert that to HDMI over Ethernet as described above.  In some very rare cases the PC is close enough to the panel to run a direct cable.  We are an isolated rural district so we don't have many other folks to bounce ideas off of.

 

Also I have wondered about how we could handle things in the future when these panels go out of warranty.  It is a real time consuming pain to RMA one of these panels when it dies.  I can swap out a lamp in a projector in five minutes.  I can swap out the entire projector in fifteen.  Those are small and cheap things we can keep as spares.  Nobody in our org and tackled the idea of what to do when these large, heavy and expensive display panels start conking out after the warranty expires.  What do y'all do in those scenarios?

 

HDMI's a horror for long cables, but we've got round it with limiting to 10m, using decent quality cables, and switching laptop display output to 30Hz. With more recent screens you can change the HDMI version or change the EDID so it doesn't think it's 4k. For some of the longer cable runs we probably would have used ethernet if we'd realised how frustrating it woudl be.

 

Replacement is an issue, and we've had a couple of screens fail already (one was already over 10 years old). We bought a "cheap" 80" Hisense TV with stand, so that's our temporary solution when a screen goes down. Not a lot of fun to transport it, although it does of course separate from the stand.

[mthomas08]

On 18/11/2025 at 09:09, BenQ_Chris said:

The other issue you have is cable length; for the most part HDMI will run 5m no problem, higher quality cable can go to 10m. But often you will need HDMI/LAN extenders. EDID 1.4 will typically give you a distance boost.

 

 

I can certainly +1 and more on this problem.

 

The active HDMIs are almost perfect, I say this because one building has the occasional issue but I believe this is more down to damage and catching the cables behind the PC.

 

We've had random drop outs with long HDMIs with the boost. We have this setup in about 30 classrooms and rarely have a problem. This is how we have the hall setup and not an issue (except again.. ball games and damages).