TS140S.1 TS140/680 Service Tip After replacing finals and/or drivers in the TS140/680 check that all filter relays are operating correctly. Failure of a band's relays to pick will cause the finals to run into an open circuit and possibly (probably?) damage them. Check the following points for approximately 12 volts. These diodes are on the filter board next to the final unit. Band Diode Band Diode 1.8 D1 24.0 D6 3.5 D2 28.0 D6 7.0 D3 28.5 D6 10.0 D4 29.0 D6 14.0 D4 29.5 D6 18.0 D5 50.0 - 54.0 D7 TS680 only 21.0 D5 If the problem is in the 1 of 10 decoder chip IC2 on the signal board (74LS145) unlock problems may also occur. Fred Burton .. @ VE3HPL