When the flash memory of your TEF20 becomes scrambled, communications cannot not be accomplished. Before attempting to reload the flash memory, verify that the following conditions exist.

1. No relay clicking is heard when TEF is powered up or when Reset is pushed. 2. Power LED is on. 3. Dip switch positions 7 and 8 are set to off (Up). (TEF Mode). 4. Dip switch positions 5 and 6 are set to on (Down) for 57600 Baud Rate. 5. You are running Sound Lab for Windows V6.6.4b or higher software.

Then ...

1. Launch TEF software.
2. Click the [Input] button on the Menu Bar.
3. Click on [Communications] on the pull down menu. 4. Under [Settings], make sure Com Port Baud Rate is set to 57600.
5. Under the [Hardware] tab, 6. Select your com port. Usually COM1.
7. You should now have an "unhappy" (green face) in the TEF Status Icon.
8. Click on [Help] - [Update EEprom].
9. Work through the test boxes - [Test Communications], [Enter Monitor Mode], [Update Flash].

If the Enter Monitor Mode button is not available, use Force Monitor Mode instead. This requires Dip Switch positions 7 AND 8 to be set to the On (Down) position.

Click [Force Monitor Mode] followed immediately by pressing the TEF20's Reset Button. This will make the Update Flash button available.

It is sometimes necessary to repeat this process once or twice to restore communications.