Need to get into the service mode of your TEAC CT-F683? Got you covered.

[albino_vulpix]

Hi all,

Long time no post, but I wanted to share. The Teac CT-F683 isn't the most well known or high-end CRT, but it seems to have been a relatively popular SCART TV in Australia, so there might be another retro gamer out there who will appreciate this information.

The standard remote control can be hacked to enter the service menu by adding our own button. You'll need some thin wire and a button of some sort; here I used a 1.4mm tactile switch.


Open up the remote control by removing the screw under the battery cover and carefully prying the clips at the side. Remove the mainboard. Locate the M34280M1 IC near the top. Essentially, we install a momentary switch between pins 2 and 18. (looking at the IC so the text is oriented correctly, pins 1-10 run left to right along the bottom, and pins 11-20 run right to left along the top).


Cut two suitable lengths of thin wire and solder one to pin 2, and the other to pin 18. I routed the wires along the side of the remote. Make sure the wires don't interfere with the other buttons.

The bottom half of the top cover can be removed to reveal some convenient blank holes. Work out where the switch will sit and trim the wires accordingly.


Solder your wires to the switch, and stick it down in place with a bit of double-sided tape. Secure your wires in place with some tape, being mindful of the other buttons' contact points. Try to get your button lined up better than I did.




Reassemble the remote, making sure your switch is accessible, and not obstructed by the cover you slid off earlier.

To access service mode, power the TV on and press the button you installed (the "Factory" button). The word Key is displayed on screen.


Press the Picture Mode button (or any of the white buttons will do) to bring up the adjustment parameters. Use the standard up/down/left/right keys to navigate and make adjustments. If you do want to make any changes, make note of the factory settings first! Apart from geometry adjustments, there are a few other options, such as disabling the TEAC logo.


To exit service mode, press the new Factory button, then the standby button to power the TV off. Turn the TV off at the hard switch to finish.

Congratulations, you can now compensate for that SCART left-shift! For other geometry adjustments, the 240P Test Suite is your friend.

[ZombieZaphod]

Hi albino_vulpix,

Sir you are a scholar and a gentleman!

This is the exact model of TV I use for my retro gaming, it's great except for that darn scart left-shift you mention. Years ago I hunted for a solution and had given up after finding nothing so the other day was stoked to randomly come across your post.

Even though I am terrible at soldering I managed to add the button to my remote and it does get me into the service menu. The only issue now is that I have no idea what setting to adjust! I did find a service manual online but couldn't make head nor tail of it unfortunately. Of course I am very reluctant to try experimenting with settings I do not understand.

Are you possibly able to give me some more information on how it fix the scart left-shift issue? I would be eternally grateful!