SB-020 Service notes on TS-700A 10-18-77 POWER SUPPLY 1. 9 volts down: The MFC4060 Q11 and 2SA495 Q9 are bad. 2. No 21V: Replace Q3 (2SC733Y (X43=1120-00) Power Supply Unit. 3. Dial light is VERY bright: Replace shorted Q2 2SA671 on rear panel. 4. Intermittant +9 volt supply: The legs of Q12 2SD235 are too short at the PC board. The leads were pulled away from the board. Replace Q12. 5. Power supply intermittant when tapped: Check for short leads on pass transistors, pulled out of circuit board. 6. No RX - No TX: Check diode D6 Zener in power supply. -6V supply. If shorted, replace. 7. No 13.8 volts at power supply: The wire on bridge D1 is not soldered. 8. +9 volts is okay, but 21 volt onl 16 volts: Q1 is bad in the power supply 2SC733Y. TRANSMITTER 1. No modulation: Replace bad diode D15 Varactor on X52-1080-21. 2. USB or LSB is too high frequency: Recheck alignment of carrier board according to TKC service Manual procedures. 3. No RF out AM CW SSB: Replace D13 on GEN unit X52-108021. 4. FM RX and TX different frequency: Readjust all HET unit frequencies. Also check VFO linearity and adjust TX frequenc L3. 5. TX wrong frequency: Adjust L3 at X52-1080-21. 10.7 oscillator for final TX frequency. 6. No power out FM: Check for loose connection at L3, the 10.7 coil on GEN unit X52-1080-21. 7. No TX or RX: The fixed channel switch is in the wrong position. 8. Low poer out only 8W. 21 volt supply down to 16V: The protection diode D7 in the power supply is shorted. 9. VFO drift: Q1 3SK22Y in VFO is bad. 10. No TX FM: D15 on X52-1080-21 GEN is bad. 11. Drive control does not peak: This is normal - leave at center 500 position. 12. No TX: TX B terminal touch to ground at X52-1080-21 GEN unit. 13. No TX FM: Check diode D16 on GEN unit. 14. Only 3 watts out: Bad Q2 2N5642 in final amplifier. 15. The RF meter doesn't Work, but TX output okay: Bad diode D1 on BPF, the 1N60 is open. 16. No TX: Bad Q3 in mixer unit (X48-1130-21) 3SK35 (BL). 17. No VFO output: Cold solder joint of R2, 100 ohm resistor inside VFO on circuit board. 18. Intermittant TX: Bad ALC pot on mixer board VR2 (X48-1130-21) 19. No TX 147 Simplex: Loose resistor not soldered on rear circuit board of band switch. RECEIVER 1. Spurrious signals on receive; if the output level or VFO is too high or mixer Q3 on HET unit: SN76514 is bad. 2. IF the noise blanker does not work: Check Q6 2SK19GR on X55-1120-00. 3. There is no audio from receiver-no 21 volts: Q1 2SC733(Y) in 21 volt supply is bad. 4. FM receiver sensitivity is down 30 - 40 db: Check 10.245 xtal at TP-1 on FM IF unit. If oscillator level is down, replace crystal. 5. Receiver sensitivity is intermittant and TX intermittant: Check contacts RT relay. Replace if bent or miss-contact. 6. If you cannot adjust the center meter: Maker sure Smeter start, VR4 is set at zero. If you cannot get enough adjustment with center meter, adjust VR1, replace Q4 (2SK19GR) on X55-1120-00. 7. No receive: Check for solder touch at 133 terminal on Het unit, if ther is no 133 het output. 8. No RX or TX and no VFO light: Check diode D2, 1N60 located on VFO circuit board. 9. VFO drifts or moves wit shock: Wire is not soldered VFO main coil L1. 10. No repeater operation: Check for wire that is touching at repeater switch. 11. No receive: Resistor R7 is touching Q1, 3SK41 on X55-1120-00 board. 12. No RX on 144, or any single band: Check HET xtals-realign the Het unit. 13. Center meter drifts for the 300000series and before: Send for the TKC bullent on Center Meter Drift. 14. VFO is intermittant when turned: There is loose tension on VFO rotor and Stator plate contact. Rebend tension spring. 15. RX audio output distorted: Chec Q4 on X49-1060-00. 16. No SSB or CW receive: Resistor R73 is touching to the can of T6 on X52-1080-21. 17. FM receive okay but SSB sensitivity is down: Check alignment of SSB IF transformers T4,5,6. 18. FM receive is bad: Bad T1 on the X48-1140-20. 19. Scratchy audio with internal speaker: Check for bad speaker. 20. No 146 band: Replace bad Het Xtal on Het Board. (c) 101877TKC