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Disabling SVM on 40H80

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Tip from David Piesina:  "WARNING! Televisions are HIGH-VOLTAGE and tinkering with them can result in SERIOUS INJURY or DEATH if you are not careful. ALWAYS UNPLUG YOUR TELEVISION FROM THE WALL IF YOU ARE OPENING IT UP. You should even let it sit for a few hours to ensure that no voltage is present in the circuitry. BE CAREFUL!!

I have a Toshiba 40H80 at home, and really wanted to disable Scan Velocity Modulation (SVM) on it. From what I've read, there is NO way to do this from the regular menu. Older models would disable SVM when you switched to Theatre Mode, but this is not the case with the 40H80: switching to Movie Mode does not disable SVM. So what to do?

I successfully disabled SVM on my 40H80 by doing it manually. I think I've found the easiest way to accomplish this task.

Want Pictures ?

Then, check out Clay Cautery's cool site.  Lots of really nice close ups on how to do this.

The new Toshiba models (my TV anyway) are a little different in that each CRT has its own SVM circuit board (for a total of three), as opposed to just the one on the green CRT with older models. The common instructions I've read indicate that you should unplug the set of two wires from each SVM circuit board. However, I found the circuit boards to seem very, very fragile, and I wanted to avoid doing this if possible. I decided to go the "power" route - cut the power to the SVM boards altogether.

This was so easy! I pretty much followed the instructions found at, with a few differences in procedure (Endaf was using a TW40x81, not a 40H80):

  1. Endaf Jones instructs you to follow the power cable from the connector on the SVM board (silk-screened P706B on the SVM board itself) to the power board which rests at the bottom of the television. This is not so easy to do on the 40H80, in that the connector to the power board is out of reach. So I unplugged the cable from the P706B connector on the actual SVM board attached to the green CRT (the one in the middle). I was quite careful to put as little stress on the board itself, and the power cable easily came out. That was it! No more awful SVM!
  2. Optional: I noticed a connector (with two wires) attached to the SVM board (green CRT) that had a cable leading to the main circuit board at the bottom of the television. Both the SVM board and main board had "123", with each numeral in a square, silk-screened on each board next to the connector for this cable. As well, the main board has a large arrow silk-screened on it that points to this connector. It may be possible that simply removing the 123 connector from the main board will disable SVM, and Toshiba is using the arrow to point it out to ISF technicians (who always disable SVM). At first, I tried just removing the 123 connector from the main board. However, I found that doing so did not produce any improvement in picture quality. I was not convinced that SVM was turned off, so I decided to remove the power connector from the SVM board. In the end, I removed both the 123 connector (from the main board) and the P706B power connector (from the SVM board). I figured the 123 connector had something to do with SVM, so what harm could it do in getting rid of it?

The picture I now get is noticeably improved, especially with hockey games. The "sugar" I used to see around the players is pretty much eliminated, and halos have been brought down to a minimum. Scan Velocity Modulation was not designed for HDTVs, and why manufacturers continue to include it on their sets is beyond me.