Is the TE35 a literal "drop-in" replacement for the T35?

My company built a machine for a customer using the T35 display (plugged into an original FEZ Spider Mainboard). The display that they are using (we believe) has failed, and only displays a white screen.

If they purchase a TE35 display and directly swap it into the machine, will there be any issues?

They are located far away from us and we are not able to make any code updates to the machine.

If they cannot just “drop-in” a TE35 display, where can old T35 displays be purchased?


I don’t think the displays are “exact” drop-in replacements, although I can’t confirm that. The screen initialisation is possibly different.

White screen is usually seen along with firmware update issues - is it possible the app has lost the screen configuration ? Can they re-flash the board at all ? Do they know if the app is running correctly otherwise?

  1. They have confirmed that the rest of the app is running normally, they are just unable to see the user interface. The machine has several buttons, lights, audio indicators, etc. which activate at various times, and all of them are activating as normal.

  2. They cannot reflash the board (easily). But might be able to be done if the TE35 doesn’t exactly swap in. By “Screen Initialization” do you mean that there may have to be changes to the code before the TE35 will operate?

  3. Could the app have lost its screen configuration due to memory loss? (is this the kind of “lost” you’re referring to?)

Thank you!

The timings are different. I checked the driver source here and found this.


HorizontalSyncPulseWidth = 41,
HorizontalBackPorch = 27,
HorizontalFrontPorch = 51,
VerticalSyncPulseWidth = 10,
VerticalBackPorch = 8,
VerticalFrontPorch = 16,
MaximumClockSpeed = 15000


HorizontalSyncPulseWidth = 41,
HorizontalBackPorch = 29,
HorizontalFrontPorch = 51,
VerticalSyncPulseWidth = 10,
VerticalBackPorch = 3,
VerticalFrontPorch = 16,
MaximumClockSpeed = 15000

So basically to get the TE35 to work you will have to rebuild with the TE35 drivers instead.


I don’t have a T35 or I’d just offer to sell it to you for the cost of a TE35 replacement. I’d bet there are others here that do have a T35 that would be willing to do the same. I can definitely understand wanting to give your client a drop-in replacement and not have them worry with updating the firmware. Good luck!

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@ Dave McLaughlin - Thank you so much Dave, just the answer I needed! Maybe we can figure out a way to have them flash the firmware themselves (or find a spare T35).

Thanks everyone else.

@ cyberh0me - We are going to have them check the system wiring, and if that confirms that the display is bad, then I may be contacting you and others for a replacement T35. Thank you.

I just swapped out a T35 with a TE35 on FEZ Spider II test board. I didn’t test the touch feature, but the display swap did work for me.

@ Greg Norris - If you can verify that the touch functionality works without any problems, your answer has me sold.

Interesting… it did not work when I tried it?

The timings are close enough that it probably will work. The backporch and the sync pulse width are just a little wider than the TE35 needs but probably still within the specs.

I have a TE35 here so I might try out the T35 timing and check it out myself.

Cool, I’m not familiar with screen-refresh parameters etc. I’ll have to look up what “backporch” means, haha. Because the screen is so cheap, we will probably just have the customer drop in a TE35 and go from there. Then support remotely if needed. Thanks all, again, for the help. I will report back to this thread to let you guys know if the TE35 drop-in works as desired.


Good news. The customer ordered a TE35, dropped it in, and the display/touch functionality worked normally. I believe that for all normal circumstances/parameters, the TE35 is a literal drop-in replacement for the T35.

Thanks again for everyone’s help in this matter.

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Good to hear, I’m sure it saved a lot of hassle.