The following procedure should correct any tendency of the TS-930S to exhibit intermittent TX power output. Most of the reported cases of this nature have been traced to poor contact of one or more plated thru holes mentioned below. Careful adherence to this procedure should prevent reoccurrance of this symptom.
Procdeure:
- Remove the top and bottom covers.
- Remove the 10 screws securing the final unit to the chassis.
- Disconnect all cable assemblies from the final assembly, and remove it from the radio. The fan motor cable may have to be removed for easy access.
- Remove all Final Unit PC board screws and turn the circuit board foil
side up.
- Desolder Q6, D2, and the plated-thru hole connecting the foils from R20 and Q8 base together (between T2 and VR1). Do not remove the components!
- Carefully remove the green solder resistant coating from the immediate areas of these six points, so that there is bare copper foill up to and surrounding the eyelets.
- Carefully resolder these six points, and those listed below:
Q1 Emitter and base
D4 anode and cathode
Q2 Emitter and base
Q3 Emitter and Base
Q7 Emitter and Base
Q4 and Q5 Base and collectors
Plated-thru hole between C36 and C15
(2) Plated-thru hole sby the molex connector.
Check and resolder the input and output coax connectors.
- Double check your work to ensure that there are no solder bridges or splashes.
- Check the value of R19. If it is not 6.8 K ohms, change it so it is.
- Reinstall the final assembly, and readjust the idle bias currents of the driver and final transistors in accordance with Service Bulletin 867.
CAUTION:
Ensure that no cables are pinched between the final assembly and
chassis when reinstalling the final unit. The fan cable is especially
vulnerable, so pay close attention!
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