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Troubleshooting



Below are some common problems and their fixes. If you do not feel comfortable making any of these repairs, then DO NOT attempt them! Please have only a competent technician perform service on your FL-7000. I assume no liability for any damage or problems caused by performing the below repairs/modifications.
  • Softstart

If you are sure the voltage selection is set right, and the power fuse is OK but your FL-7000 will not power up, the following is the most common cure:


Replace R01 = 10 Ohm, 10 watt, R02 = 27 Ohm ¼ watt and D01 = 1N4001 (Standard Diode)


These components are located right behind the rear panel near where the power cord enters. See the FL-7000 Manual on this site for help.



  • Common problems during shipping

Most cases after return, the fan shrouds are slightly bent in from the sliding weight of the FL-7000 bumping the sides of the shipping box. This can cause many problems when and during operation due to the fact that one or both fans can not spin free causing an overheat condition. Assure that BOTH fans are spinning free and have no restrictions.



  • Above 50 VCC

Most common cure:


An above 50 VCC is usually a result of an overdrive condition from either an FT-1000MP Mark V Power Spike (see FL-7000 Care) or a constant tuning on a lower band. When this happens, it is most likely two parts that go bad, however a failure of a third part is possible. The parts to test and/or replace are: Q005, Q006 (2SD797Y) and Q007 (2SB5950). These parts are located on the Power Supply Heat Sink towards the rear of the FL-7000 near the rear fan. There are many substitute parts that will work, so do not limit your self to the exact part number. NTE and ECG are just a few cross over compatible parts manufacturers.



  • Low Power Output

Its sad to say, but in most all the cases of low power output, the problem results from either one or more RF Power Transistors becoming weak. It is impossible to test these transistors with a typical digital volt meter in the diode check position and even if you do find an open transistor, you must replace them in matched pairs.


Don’t be alarmed though, because ICOM still sells the 2SC2652 transistors (used in the ICOM solid state rigs) and other replacement transistors are available. (See FL-7000 Parts)


There is one other possible place to look for low power. One in every three units have this problem, however is not always apparent. If your FL-7000 is drawing the proper current (viewed on the FL-7000 current meter during transmit) however you still have low power output, you are in luck. Usually a very heavy toroid on the combiner unit will break free (glued) causing ½ of the combiner to loose solder connection to the circuit board, reducing power by half. You will need to remove the combiner unit which is located in the front right corner of your FL-7000 under the screen mesh. This unit can be removed without disconnecting all the wires and connectors by:

  1. Remove the screen mesh cover held in place with 4 screws.
  2. You will see 3 gray coax connectors that are plugged into the LPF board (right most vertical board next to the combiner).
  3. Remove the 3 coax connectors (one is a sub miniature coax connector, the other two are phone style connectors).
  4. Remove the 4 screws that hold the combiner into place located at the base four corners of the combiner.
  5. Roll the combiner upwards and over the power transformer. It will actually lay on the power transformer.
  6. Look at the LARGE black toroid on the side of the cooling fin assembly (combiner board) and check to see if the toriod is “glued” in place or it broke free.
  7. If it is broke free , remove the combiner circuit card from the cooling assembly and verify that all the wires from the toriod are soldered to the circuit board and that none of them broke free.
  8. If any are broke free, repair them and reassemble the unit for test, you WILL have full power again!


  • Loss of LEDS on Front Panel

Most common cure:


Typical loss of the LEDS on the front panel are a result of either the 8 volt regulator OR the 12 volt regulator opening up. It is usually a result from the regulator's mounting technique. They are screwed onto the heat sink plate on the rear power supply and eventually in shipping from point to point become loose, overheat, and open.


Replace Q01 = LM-7812 and the Q02 = LM-7808 on the bottom side of the heat sink on the main 47 VDC power Regulator located in the back left corner of the FL-7000 near the rear fan.


  • Tuner not working

Most common cure:


This works EVERY time I have tried it. If your Automatic Antenna Servo Motors are not turning (The ones attached to the variable capacitors) Simply follow these instructions.

  1. Remove the bottom cover on the FL-7000 and gain access to the Variable Capacitors connected to the servos located under the tuner unit.
  2. Power up your FL-7000 leaving the unit upside down.
  3. Push in the TUNER button.
  4. Apply the exciter at about 70 watts.
  5. Press the TUNE button on the FL-7000.
  6. While it is in the tune mode QUICKY move the capacitors by hand back and forth (limited to as much travel as you can).
  7. I’ll bet they start working again!
  8. After they become functional again, lube them with WD-40 at the SERVO ONLY which is the shaft from the servo to the capacitor.
  9. Replace the covers, your tuner now works.


  • Bands not tracking

Most common cure:


In most cases when the band will NOT track while connected to a Yaesu transceiver Band Data Output, the problem is located on the main processor board.

  1. Remove the side rails, top, and bottom covers.
  2. Remove the end trim pieces and screws holding the front panel on.
  3. Only remove the top front panel screws on the sides to allow the front panel to “swing” open.
  4. While the front panel is resting 90 degrees from the chassis, you now have access to the processor board that IS mounted on the front panel.
  5. Replace Q01 = UPD7507C. Replace D38, D-39, D-40, and D41 (1N914 diodes from Radio Shack)


  • Antenna Ouput Selector Not Working

Most common cure:


If the Antenna Selector Ports on the back of your FL-7000 are not working,

  1. Remove the side rails, top and bottom covers.
  2. Remove the end trim pieces and screws holding the front panel on.
  3. Only remove the top front panel screws on the sides to allow the front panel to “swing” open.
  4. While the front panel is resting 90 degrees from the chassis, you now have access to the processor board that IS mounted on the front panel.
  5. Replace Q004 , Q005 and Q006 (2SA733A) *** Found all over inside CB radios ***


  • Trip out

Normally, trip out occurs when either too much power is applied from the exciter, or there is a problem with the PA Modules. Part of the modifications that I perform on the FL-7000 is to desensitize the part of the protector board that causes a shutdown from something other than a possible fault. i.e. it actually relaxes the unit slightly.

There are several other ways that “trip-outs” can happen though and one of them is the input power. If the input power drops to around 90 to 100 VAC, the regulator compensation will not allow for the drop, causing trip out. This becomes tedious because you have to shut the power off and turn it on again and sometimes it happens 4 or 5 times every time you are in QSO. This problem as well is modified to allow more of a voltage drop without trip outs.

If your FL-7000 trips out the second you key the transmitter, chances are that the PA Modules are bad, the RF Transistors need replaced, OR the power regulators are open and the VCC reads above 47 VDC on the meter located on the front.

  • Fans not operating

If the fans will not operate even with the FAN1 and FAN2 LEDS Illuminated, change the following components in this order, (one at a time) until they restart.

D09 (1N914)

D10 (1N914)

D13 (1N914)

D14 (1N914)

D18 (1N914)

D19 (1N914)

Q-6 (2SC1815Y)

Q-7 (2SC1815Y)

Q-8 (2SC1815Y)

Q-9 (2SC1815Y)

D-20 (S12MD22)

D-21 (S12MD22)



  • Fans always running at high speed.
Most common cure:

When the FAN LED comes on, usually the fan will run at a very slow speed, then, depending on how hard the amplifier is working, will ramp up to a high speed for a short period of time. After sufficient cooling has been reached the fan will slow back down to a slower speed. If the fan goes straight into HIGH SPEED, the HIGH SPEED thermal sensor on the P.A. unit is most likely shorted. Check all three sensors for greater than 10K ohms when cool. The HIGH SPEED Sensor is the one single sensor on P.A. 2. (60 Degrees C) The other P.A. has two sensors (40 and 80 Degrees C).



  • Fans not shutting off

If the fans do not shut off even after the FAN1 and FAN2 LEDS are off, replace D-20 and D-21 on the Protector Board.



  • Power Supply warning LED comes on

Typically if the Power Supply Warning LED is illuminated, it is a result of the rear fan not operating. Out of ALL the units I have ever worked on I have noted, there is something, either a wire or a bent fan shroud from shipping that keeps the rear fan from coming on. If you can “spin” the rear fan without hearing any clicks or rubbing sound you are OK. The only other thing is the fan itself may be defective and needs replaced.



  • Fans not working after power off

The fans SHOULD run during a warm cycle even after the power is turned off (Green FAN1 and FAN2 LEDS ON). If the fans run during power on and you shut the power off and the fans go off as well (FAN1 and FAN2 LEDS OFF) replace the relay on the protector board. Relay location is RL01 and also replace D-17.



  • Unit will not turn on
See "Soft Start"


  • PA Resistance check

A quick verification to see if a power supply problem is a result of a faulty PA unit,

  1. Remove the screen mesh cover held in place with 4 screws.
  2. Remove the RED VCC wires, one on each side of the PA unit.
  3. Using a Digital Ohm Meter, read the resistance from the RED terminal (where you removed the RED wire) to the BLACK VCC wire which is still connected.
  4. Resistance should be greater than 500K Ohms to Open.


  • Thermal Compound of RF Transistors

The Thermal Compound on the RF Transistors located on the Power Combiner unit, have a tendency to become “hard” after years of use. This “hard” transformation can actually damage the unit by excessive heat transfer reduction from the component to the heat sink and bias limiting diode. It is recommended that you replace this heat sink compound, at least the compound on the diodes, every-time you have the amplifier serviced.


To replace the heat sink compound, follow the same instructions listed in “Low Power Output” above to gain access to the power combiner unit.



  • Lithium Battery replacement (both batteries)

There are two Lithium Batteries in your FL-7000. One is on the Main Processor unit behind the front panel and the other on is on the Automatic Antenna Tuner processor board. Which ones do you replace? If they read low voltage (below 2.8 VDC) OR:

  1. Replace the battery on the Main Processor if the LEDs for tracking do not resume where they were during a power down, power up cycle. i.e If you were on 17 meters , turned off the power for a while and turned it back on and the LED shows 160 meters.

  2. If the unit does not remember the last tuned state during a power down, power up cycle and ONE band change with the TUNER ON , replace the Lithium Battery on the Antenna Unit CPU. Both can be changed with minimum teardown of the unit if you are good with a soldering iron.


  • VAC Wiring



  • LAMP Replacement
Lamp replacement may be one of the most “fun” and tedious jobs on the FL-7000. I am going to walk you through step by step in how to replace the meter lamps in your FL-7000. The bulbs are standard 12VDC mini fuse type and Yaesu still has them in stock at about $2.50 each. Total time for this task is about 30 to 40 minutes.
    1. Remove the Top , Bottom , Side Rails , End Caps from the FL-7000.
    2. Remove the top and bottom screws located on the top and bottom of the front panel bezel. *** No need to remove the screws that hinge the front panel to the body of the FL-7000 located on the sides of the front panel ***
    3. With a sharp jerk, pull the front panel bezel off of the main processor board and chassis. *** NOTE, DO NOT WIGGLE IT, PULL IT STRAIGHT OFF!!! Or you will be fighting LED alignments for hours getting it back on*** The Buttons for VCC , SWR , ALC and Power MAY come off , this is OK.
    4. The meters MAY fall out by themselves; however the wires will hold them from falling very far.
    5. Set the front panel off to the side out of the way.
    6. Do not put ANY finger prints on the inside plexiglass, it becomes a bummer later.
    7. Next, hold one of the meters in hand and you will see the clear plexiglass of the meter is held to the face of the meter with scotch tape.
    8. Using an exacto knife in the groove, slit the tape all the way around the plexiglass where the face is attached cutting the tape that holds them together. *** DO NOT CUT THE CHROME TAPE ***
    9. Remove the clear plastic from the face and be sure NOT to touch the meter movement.
    10. The bulb is now visible for replacement using a soldering iron using LOW heat and solder FAST.
    11. After the new bulb is soldered in place, replace the plexiglass using a few small strips of scotch tape wrapped around the rear of the face and sides of the plexiglass.
    12. Use a small piece of scotch tape to “hold” the meter(s) back in place for front panel reassembly.
    13. Clean the plexiglass on the meter(s) with Windex before you go to the next step.
    14. Just as you “jerked” the front panel straight off, line up the LED’s with the holes in the front panel perfect before you “push” the front panel back on. ***DO NOT TOUCH THE LEDS OR MOVE THEM *** It is easy if you use the four buttons (Pwr, Vcc , Etc) for alignment. It will slide right on. You have ONE try.
    15. Reassemble the hardware and covers.
    16. Task complete.
Meter
Meter Lamp
Lamp Out


  • VCC Low (below 20 VCC)

If you turn on your FL-7000 and the VCC reads below 20VDC on the FL-7000 meter, then the problem that is common in most cases is a shorted Power Output Transistor (2SC2652). There are a number of ways to find out that this is the case. The fastest way is to:

  1. Remove the side rails, top cover.
  2. Remove the screen mesh that covers the combiner assembly.
  3. Remove the LARGE RED wires on the combiner. There will be two of them, one on the front side of the combiner and one on the back side of the combiner. They both have BLACK wires next to them.
  4. Isolate the wires so they will not touch anything when the FL-7000 is powered back up.
  5. Turn on power and view VCC to see if it comes back to 48VDC. (on the FL-7000 Meter)

If it does come back to the normal 48 VDC, then power down and hook ONE red wire up and try it. If it still reads 48 VDC, then the side with the RED wire not hooked up has the problem. If it does read low voltage, then unhook that RED wire and hook the other RED wire up and try it to verify only one side of the PA has a problem. Replace BOTH RF Transistors on the bad side, replace the RED wires and you are good to go.


  • General teardown
  • Unregulated VCC during key-down
  • Common SERVO problems with easy fixes
  • Ordering replacement parts
  • Common Checks while you have the unit open
  • Inside Pictures
  • More to come...