I volunteer at the old Loews Jersey theater in Jersey City. Our main digital projector is a Digital Projection Lightning 35HD. It’s about 15 years old now, and had been working until it failed the other month.
If your 35HD has not yet failed, please read my other post about important maintenance procedures you need to do while it’s still working. Once you’ve done these procedures, then come back and learn more about the inner workings of the 35HD.
If your 35HD boots to a white touchscreen, what is likely the issue is that the CMOS battery has failed. Without valid CMOS contents, the computer inside the 35HD is paused after booting, waiting for you to use a keyboard to reset the CMOS state. Here’s how to handle it.
What you will need:
- A new CMOS battery. I don’t know if all 35HDs are using the same motherboard, but it’s probably a 2032.
- A keyboard with a PS/2 connection.
- A way to connect the VGA video. The best way to handle this is to custom-wire an adapter. Any way that allows you to connect up individual pins on an IDC connector will do.
Step 5: Plug in the keyboard. You’ll find a PS/2-style keyboard connector near the RJ-45 jacks on the motherboard. This will be in the lower-left of the motherboard, as it was oriented originally while installed on the projector. The keyboard port will likely be blocked by one of the large standoffs. You can carefully unscrew the standoff, and that will allow you to reinstall it later.
Step 6: Install a VGA adapter. I wish I had pictures of this pin header on the motherboard, but I failed to capture it.
In the very corner of the motherboard is a pin header labeled “TV1”. Right next to it is an IDC-10 socket labeled “VGA1”. If you have the time to create a custom cable, that’s preferred. If not, then use whatever random collection of jumper wires you have available to make the connection. (We used female to female jumper wires from the IDC socket, we wire-wrapped directly onto the pins of a VGA cable, and just bodged the wires together in the middle. That’s not really preferred, but you do you.)
IDC-10 “VGA1” pinout:
- Pin 1: Red. Connect to VGA pin 1.
- Pin 3: Green. Connect to VGA pin 2.
- Pin 5: Blue. Connect to VGA pin 3.
- Pin 6: Ground. Connect to VGA pins 5, 6, 7, 8, 10. Or connect to just one of them, as your monitor will likely just have all those pins connected together anyway.
- Pin 7: HSync. Connect to VGA pin 13.
- Pin 9: VSync. Connect to VGA pin 14.
Step 11: Your projector should boot up and use the touchscreen. If you didn’t plug in all the cables, you’ll get some various warnings. That’s fine. Just verify that the touch screen shows an image and that its touch capability works.
Step 12. Power down the projector. Remove the computer module. Return to your desk, and disassemble the computer module enough so that you can remove the VGA adapter. Keep that adapter safe. Unplug the keyboard, and reinstall the standoff that you unscrewed. Carefully reassemble the computer module, replugging all the parts and reinstalling all the pieces and cards you removed. Screw the case together, reinstall the module onto the projector, and plug in all the cables.