Tutorial originally prepared by Hans Eilers - 18 February 2005
with several community updates and additions over the years

This guide was originally written at a time when it was a simple matter to run to the nearest store and buy a glass CRT television. Although this is no longer the case, all of the following concepts are still valid and arguably superior to the use of an RGB monitor, and a 19-inch CRT TV should still be easier to find these days than a new monitor.

"Well what about using a modern flat panel display? Wouldn't that work?"
With all classic arcade games, using a flat panel display is a practice that has primarily arisen out of desperation (or ignorance)... so, just be aware... doing that would create a very obvious indication of desperation (or ignorance). It would also bring additional mounting challenges and a depreciative effect on the cabinet as a collectible. Only 19-inch CRT televisions that match the physical profile of the original monitor should be used.


Replacing the monitor in a Dragon's Lair / Space Ace / Thayer's Quest game with a CRT TV can be the easiest, most economical solution, providing an excellent picture with no permanent modifications and no additional hardware. As original Electrohome G07 and Wells-Gardner WG4900 monitors with little or no burn-in are getting scarce, finding a suitable replacement presents a challenge. A new RGB monitor is expensive and needs an NTSC to RGB conversion solution, which often times requires hacks. A compatible TV accepts the laserdisc player's NTSC signal natively, and thus a conversion card is not needed.

The reason why a TV substitution is possible is because the Dragon's Lair, Space Ace, and Thayer's Quest games send only the laserdisc player's video output to the screen and nothing else. For games like Super Don Quix-ote, which display computer-generated overlays on the video, this straightforward TV swap is not an option.

The TV model used most for this conversion is the Symphonic ST419D (made by Funai). It has also been marketed as a Sylvania or Funai TV. This model has two crucial features that make it the best choice. First, it remembers that it was powered on when it gets unplugged during use, and it will automatically power on again when it is plugged back in. It also remembers the channel or input setting when plugged back in. These two features make it most like an arcade monitor because it just powers up and works. If you use a TV without these features, you'll need to manually turn it on and/or adjust the source input with the remote control each time.

First things first: the WARNINGS and DISCLAIMERS. Video game monitors and televisions contain potentially LETHAL voltages, so one must take care and use caution. This document is meant to be a guide only, and you agree to undertake this on your own. By following these procedures, you are solely responsible for any damages.

REMOVING THE OLD MONITOR - (Electrohome G07 is represented)

First, disconnect the video cable going to the NTSC board. Now disconnect the power to the monitor. This should be a small, 2-wire Molex connector. Before you remove the old monitor, discharge the tube. Monitors can store a fairly significant charge even after being off for some time. Make sure the game is unplugged. Using a long flat-blade screwdriver, connect one end of a wire (preferably insulated) with alligator clips to the screwdriver's metal shaft and the other end to the metal frame of the monitor chassis. Using one hand to hold and touch only the plastic handle of the screwdriver, push the metal end of the screwdriver under the big suction cup (anode) on the top of the tube, making full contact between the screwdriver blade and the anode connection at the center of the suction cup. You may hear a POP and may see a nice blue spark. Remove the screwdriver, wait five minutes, and repeat.

Now for the hardest part of this whole procedure: unbolting the monitor frame. This is difficult only because getting to the four bolts to remove them is difficult, especially for someone with large hands. Using a 1/2" socket, remove the four bolts holding the monitor frame in place. (Do not remove the bolts going through the wooden sides of the game cabinet.) It's probably a good idea to have someone else help you hold the monitor as you remove the bolts. Now very carefully slide the monitor out of the back of the cabinet.

discharging the tube  monitor brackets


After pulling the monitor out of the cabinet, you are ready to remove the chassis and the tube from the metal frame. This guide will have you remove them in separate pieces instead of together as a whole, because a freely-swinging chassis still connected to a tube could crack the neck. Having already discharged the monitor above, it should be safe to remove the anode by using the screwdriver to squeeze together the two hooks under the rubber suction cup and pull them out. Now gently remove the neck board from the tube. Also remove the ground wire from the neck board. Next you will want to remove the yoke connector (large 5-wire connector on the chassis near the flyback). Last, remove the two white wires connected to the degaussing coil (these are found on the left side of the chassis). Now everything should be disconnected from the chassis. Remove the two screws on either side holding it in place, and gently remove the chassis.

G07 removed from game  removing the G07 neck board  G07 chassis removed


First, remove the screw holding the degaussing coil wiring (it's the only thing left on the frame except the tube). Now from the front, remove the four 3/8" bolts holding the tube to the frame. Take care, as the tube is heavy and may tip over when it's loose. Be careful of the neck, and gently set the tube face down on a towel, bubble wrap, or something else to protect the screen. That's it! You should have a bare metal frame ready to install the TV onto.

monitor bolts

TESTING THE TV - (Symphonic ST419D is represented)

Prior to disassembling the TV, it's probably a good idea to connect it to the game and make sure that it works. Connect the laserdisc player to the TV's front video input with a BNC to RCA connector. Plug in the TV, turn it on, and set it to the front AV input selection ("GAME"). Fire up your game, and see how great it's going to look. Now, unplug the TV while it's still running, wait for a minute, and then plug it back in again. The ideal TV will resume playing normally without needing to be turned on again nor having its input selection set to "GAME" again. When you're finished testing, unplug the TV while it's still running, so that it will be ready to work properly the next time it's powered on inside your game cabinet.

BNC to RCA connector


After testing, disconnect the laserdisc video cable from the TV. Place the TV face down on a table or bench, on top of a towel, bubble wrap, or something else to protect the screen. Remove the screws on the back of the TV, then confirm that the power cord is unplugged, and gently remove the back cover. Discharge the tube following the same steps above in the REMOVING THE OLD MONITOR section.

Remove the two screws on the bottom of the TV that hold the chassis in place. There are two cable ties on each side of the bottom part of the tube. Carefully snip these off to give more room to move the chassis around, and remove the chassis from the base. Now remove the four screws in the corners holding the tube to the front TV plastic. For the last step, it's probably a good idea to get someone to hold the loose chassis as you gently lift the tube out of the front plastic. Slide the front plastic out of the way, and set the tube face down on the towel or bubble wrap.

inside the TV case


Carefully place the monitor's metal frame around the TV tube and line up the four bolt holes. Insert and hand-tighten the four 3/8" bolts so that the TV tube is fastened to the frame like the monitor was. Gently set the frame upright, and tighten the four bolts completely with a socket wrench. Set the chassis down on the base of the frame for now, while you build a mounting board for it. Be aware that the tube will be top-heavy with a tendency to tip over.


Mounting the chassis to the frame is where some of the "engineering" comes in. While the TV chassis is close to the same shape of the monitor chassis, it doesn't line up to the mounting brackets on the frame. The best way to deal with this is to cut a piece of board or wood to mount the chassis to. Cut an 8" x 9 3/4" piece of 1/2" wood, which will wedge neatly between the old mounting brackets on the frame. Mark and a drill a pilot hole into the left and right side edges of the board where it is aligned with the slot in each of the two larger side brackets, so that you can attach the board to these brackets with screws later, after mounting the chassis onto the board.

mounting board

Rotate the chassis 90 degrees clockwise so that the front AV inputs are to the right and the RG6 cable input is to the left. This allows for the easiest attachment of the cables and allows access to the front panel control buttons and the IR "eye" for the remote control. If you did cut the two cable ties earlier, you should have enough slack in the cables.

TV chassis mounted

There are multiple ways that you may secure the chassis to the mounting board, such as with a plastic PCB edge mounting kit. In this guide's photos, plastic cable clamps doubled-up inside each other were used as stand-offs as well as for cord-routing. The chassis was centered on the mounting board, and the positions of the holes in the two far corners were marked for drilling. This particular chassis has no mounting holes in the near corners, so two positions were selected and marked for stand-offs to go underneath the near corners of the chassis. Pilot holes were drilled into the mounting board for the cable clamps in each corner.

cable clamps

For the near corners, the mounting screws were inserted in-between the plastic tabs of the cable clamps to avoid electrical shorting, and the clamps were tightened down. The near corners of the chassis are resting on top of the plastic tabs without touching the screws between the tabs. For the far left corner and the far right corner, the screws are going through the holes in the chassis, then through the cable clamps, and then they are tightened to the mounting board with the TV's power cord also running through a clamp.

far left corner  far right corner

This leaves the near corners of the chassis sitting loose on the plastic while the far corners are anchored firmly. While this may be sufficient for a careful home environment, other mounting kits or methods may secure all of the edges or corners, leaving nothing precarious to remember in the future.

With the side edges of the new mounting board attached with screws through the slots in the brackets on the frame, the TV chassis is successfully mounted.


OK, this part can be tricky without some help. Make sure the power cord is wrapped up and out of the way. Carefully lift up the frame and place the bottom end in first on the game cabinet's mounting brackets. Be very careful of the neck of the picture tube while you do this. Slide the frame down the brackets until the mounting holes line up, and then hold it squarely-positioned while your assistant inserts the bolts from the top. This can be tricky, as there is not much hand room here. After your assistant hand-tightens all four nuts as best as they can, tighten them with the 1/2" socket. With everything secure, check the alignment in the front.

The next step prepares the TV to be connected to the game cabinet's original Molex connector on the power cable to the monitor. Cut the plug off of the TV's power cord, and install a 2-position female .93 Molex connector onto the cord, like the one found on the original monitor. Plug it into the game's original power connection, which is protected by the cabinet's isolation transformer.
Do not use the TV's original 2-prong plug in any outlet that bypasses the safety of the isolation transformer.

Lastly, connect the video cable from the laserdisc player to the TV chassis (on the yellow connector) using a BNC to RCA connector.

TV installed in game cabinet


OK, now for the moment of truth! Double-check all your work and connections. Plug in your game and turn it on. If the TV was last unplugged while you had it running on the "GAME" input during testing, then it should turn on now, and you should see the word "GAME" briefly on the screen in the upper right corner (if you are using the Symphonic TV). If not, just walk around to the back and use the remote to turn on the TV and set the input selection. The ideal TV should now remain that way every time you turn the game on.

GAME is shown on-screen  Dragon's Lair title screen


Additional "secret" fine adjustments to the picture quality can also be made. The Service Manual for the Symphonic ST419E Television describes on page 5-1 (PDF page 18) a procedure for adding one jumper wire to the remote control that will convert it to a "service remote". This service remote can then be used (as described throughout the rest of section 5) to make "electrical adjustments" to the image, including vertical & horizontal size & position, black level, white balance, and more. In addition to the ST419D model, it is currently unknown how many other different models of Symphonic/Sylvania/Funai televisions these procedures might also apply to. Thanks to Michael Giannasio for pointing this out.

That's it!! Enjoy your Dragon's Lair with a brand new, bright, clean, clear monitor!


This tutorial was organized subsequent to shared accounts of monitor-to-TV swaps that had begun among the D-L-P collector community and gained popularity, to safely guide those who would like an easy solution to replacing the monitor in their game. While this tutorial was written specifically using the Electrohome G07 monitor and the Symphonic ST419D TV, many of the concepts discussed here can be applied to the Wells-Gardner WG4900 monitor and to the use of other TV models.

Special thanks to Jeff Kinder, Michael Fox, Dave Hallock, and the D-L-P community as a whole.

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