Hacking Camcorder CRT Viewfinders




Posted in TechnologyReuse

Introduction: Hacking Camcorder CRT Viewfinders

About: Twitter: @devicemodder1

This Instructable will teach you how to identify, hack and use an old camcorder CRT viewfinder without the use of a service manual as those can be hard to come by (especially for older cameras). These little tubes are great for things like Heads Up Displays (HUDs) eg, wearable computers, and many other uses. They usually take standard composite video which is nice.

These viewfinders can usually be found on 1980's era camcorders and can be acquired pretty cheaply from thrift stores/flea markets/eBay.

I will put this here: CRTs contain hazardous voltages within and I will NOT be held responsible for your safety. USE caution when performing the operations outlined in this instructable.

Step 1: Materials and Items/Tools Required

The list of Items required for this

  • Digital Multimeter or other device for testing continuity. (LED and battery work here).
  • Variable power supply or standard ATX power supply (for figuring out supply voltage for the tube)
  • Phillips head screwdriver (not shown)
  • alligator clip leads for power supply and video source.
  • RCA connector, color doesn't matter here.
  • Source for composite video (in this instructable I will be using an old compaq armada)
  • wire cutters/strippers
  • that should be it for tools

Step 2: Opening the Viewfinder

Pretty self explanatory. Just find any screws and remove them.

The locations of screw holes can vary between manufacturers so the number/location of screws depends on your model/unit.

Step 3: Finding the Ground Pin.

To find the ground pin What you do is look for any component with a metal enclosure and touch one lead of the multimeter to there, then touch the other lead to the connector where the main cable comes in. Make sure the meter is set to continuity, EG diode test mode. The reading you are looking for in the meter should be around 1-2 ohms.

Step 4: Finding the Power Pin

To find the power pin, look for a nearby fuse or a thicker trace coming from the pins. mark these on the bottom of the board or write it down somewhere so you don't forget them because they are needed in the next step.

If the camera powers up still then just check the pins with a multimeter till you locate the power pins and check the voltage. write down any pin numbers/voltages before taking the rest of the camera apart. Do the above (first sentence) IF the camera wont power up. The displays do not have any voltage regulators as they are fed from the camera directly.

Step 5: Figuring Out the Voltage of the Viewfinder

This is relatively easy once you have found the power and ground pins. Connect your power source to the conncting wires that plug into that connector of the viewfinder and set the power supply voltage to its LOWEST SETTING. Once that is set, SLOWLY increase the voltage to 5 volts while watching the CRT. when the screen glows you have found the input voltage. If not, then increase the voltage till the screen glows. DO NOT EXCEED 12 VOLTS.

This is the part where you want to be careful as the CRT can contain high voltage.

Step 6: Figuring Out the Video

This step is relatively easy too. get an RCA connector and connect the outer copper to the video ground. This can be figured out the same way as with the power ground. Then connect the RCA connector to some device with composite video, an old portable dvd player works well. get the center white/yellow/red (whatever color is in your cable) wire and probe the rest of the pins till you see an image on the screen. When you see an image, write down the wire colors or pins.

Use caution here too with the CRT because of the voltage it produces ~500-1000V

see the image notes for the first image for my video wires. On mine, green is video ground and yellow is video in.

Step 7: DONE

Put the display back together and have fun. use it with a raspberry pi, or other things.

Hope you like my instructable. Feel free to leave any comments.



  • Microcontroller Contest

    Microcontroller Contest
  • Science of Cooking

    Science of Cooking
  • Pocket-Sized Contest

    Pocket-Sized Contest

We have a be nice policy.
Please be positive and constructive.




I did something somewhat similar a couple of years ago. I used the B&W viewfinder CRT from an old camcorder, put a cheap-o "backup camera" for a car on it, put a IR LED ring around the camera, and have a small, battery-powered pocket night vision rig. I like to sit on my porch and see the critters in the woods at night :) I still use this little rig almost daily.

With the IR camera, I found the B&W tube works a lot better than the (seemingly somewhat rare) mini color viewfinder CRT's.

Great Instructable!!

2 replies

Also, nice job on the night vision scope :-) If this was reddit you'd get my upvote.

Are my eyes tricking me or is that a color CRT? I found the name of the model once that had a color viewfinder but have lost it. Also curious as to what camera that came out of as all of the ones I get are round, not square.

Has anyone ever used a sony crt? I've gotten two camers and both CRT displays do the same thing, they just flicker and buzz no matter what I do. Any ideas at what I'm doing wrong? They work fine in the camera itself.

2 replies

the camera powers up? then measure voltages on the connector and disconnect everything on the video cable but the power, then reconnect the other wires till the camera image comes back.

Excellent Project. I like to Hack and Mod and moreover Reusing old. +1 to your efforts.


2 replies

Glad you like the instructable!

We have a "metric-asstonne" of old camcorders at my school... i am going to try this as a science project...

I'm finding step four to be absolutely brutal. I can't find a fuse anywhere on this thing

1 reply

Try to look for a thicker trace or a main capacitor.

That's a great idea. Combine it with a small camera and there you go.

great work! but what is the" Step 8", by the way O(∩_∩)O

1 reply

Step 8 was a typo. There isn't a step 8. Sorry for the late reply. I have been busy.

Great instructable. Hope you have more like it in the future. Personally, I just love the junk store looking for stuff to reuse, repair and repurpose.

1 reply

I got a few tape decks that I need to repair, so I may be busy for a while.