1. Launch TEF software.

2. The windows program has a communications icon, which is a little face at the top of the screen. If he is yellow and smiling, you have communications. If he turns green and frowns, you do not have communications. If he has a little red hat, you are working on Christmas Eve or Christmas Day. The TEF can be re-set by clicking on the communications icon, or if that is not successful, press the re-set on the front panel of the TEF.

3. Click the [Input] button on the Menu Bar.

4. Click on [Communications] on the pull down menu.

5. Check that you have the correct port selected. Serial requires COMx Parallel requires LPTx HI Card requires HI USB requires USB
6. Check that all cables are securely fastened to the TEF and to your computer. A loose cable connection can cause communications errors. If a TEF clicks its relays when you push reset, but does not communicate, it is probably either the cable or a wrong port selection.
7. Try re-booting the computer. Sometimes, windows will forget to recognize the port even when the hardware profile says it's active.
8. Every now and then a TEF will get jarred and the cable going from the digital board to the analog board will get knocked loose. To check this, turn the TEF off, remove the power cable from the TEF, remove the top cover from the TEF, and looking at the TEF from the front you will see a flat ribbon cable that goes from the board on the left (digital board) to the large board on the right with the mic inputs (analog board). Normally, if they come loose it is at the analog board side. There are hold-down clips, but from time to time it still happens. While you are inside, there are a series of socketed chips. Gently press down on the socketed chips to make sure they are seated.
9. The final step is to check the e squared communications code. In DOS click on [File] and [About].
In Windows click the [Communications] icon.
It should read e-squared code versions. If it shows all zeros (DOS version), or says TEF not communicating (Windows version), then you will need a DOS Disk called Util 1.2, Vers. 1.39 and a serial cable.
Run the program and follow the instructions in the install program. Locate the dip switch labelled "Status" on the TEF's rear panel. Please note that when it says monitor position, it assumes that switches 5 and 6 are on (down). So, monitor is typically 5,6,7,8 on. When done with the update, re-set the dip switches to 5,6 on, for 57,600 baud rate. If the update is not successful, try shutting off the TEF, and removing the flat brown cable that goes from the power supply board (big transformer/capacitors) and the analog board. Remove the connector from the analog board side. (See illustration for step 8.) If a relay sticks on the analog board, the TEF will not communicate. When you remove the power, the relays will often re-set, and you can also try reloading the code with the power connector to the analog board disconnected. It goes without saying, that one must be careful when working around live wires. And, capacitors can carry a significant charge even when the TEF is turned off.