FAC0392%UOFT01.BITNET@WISCVM.ARPA (11/14/85)
From: FAC0392%UOFT01.BITNET@WISCVM.ARPA (Len Brady) Received this today with my TNC-2 Revision 2 front panel (lovely!) Re: Problems with TNC 2 Rev. 2 The first of the second shipmentof TNC 2s has hit the field, and some problems have been identified. The following information applies only to TNCs with an ORDER NUMBER greater that 511, those that say Rev 2 below U21. ---------- Symptom: During the test on page 44, the STA light fails to go out. Solution: The manual fails to tell you to install U24, the second 6264-L. Remove power and install this chip. ----------- Symptom: The digital loopback test on pages 47 & 48 fails. No CONNECTED nessage is displayed. Solution: SOME, not all, of the state machine proms (U6) were programmed incorrectly, To see if this is your problem, perform the following steps: 1) Remove power 2) Remove U5 (74HC374) and U6 (2716 marked STATE) and place on the black protective foam. 3) Install a jumper between U21 pins 13 and 14 4) Install a jumper between U21 pins 12 and 15. 5) Check for shorts. 6) Apply power, try digital loopback test again.. If the test succeeds, you have a bad U6. To double check, swap U6 with any other working state machine, either from a TNC 2 rev 1 board, a working TNC 2 rev 2, of the K9NG 9600 baud modem board. If your U6 is bad, put it on a small piece of the black foam, put the chip and foam in the small box your sockets came in, and send the box back to TAPR. We will return it ASAP by first class mail. ------------ Symptom: Your front panel is missing. Solution: No one got one. A sheet notifying you of this was left out of the box. The panels will be sent to you via first class mail by the end of the week. ------------ Symptom: Your board says Rev 2, but the manual says Rev 3. Solution: Replace Rev 3 with Rev 2 in the manual. There is no Rev 3. ------------ We apologize for these problems. Remember, the preceding applies 5nly to TNC order numbers greater than 511 (rev 2). Owners of TNC 2 rev 1 (order numbers less than 512) will want to be sure to see the next PSR, it contains information on how to upgrade your TNC to Rev 2. PSR should be mailed in the next 7 days. +++++++++++++++++++++++++++++++++++++++++++++++++++++++ Good luck to all and see you on packet soon. 73, Len KF8J <FAC0392@UOFT01.BITNET>