
Airport Systems
Flashhead does not
flash
Is FH Flashtube
broken?
No
Is THVB DS1
High Voltage
Indicator Lit?
No
Remove Power at
Breakers. Discharge
Capacitors.
Is FH capacitor C1A, C1B, C2, C3, or C4 shorted out?
No
Select Manual Day
Mode from FH Switch panel. Apply power to Flashhead.
Does K3 Relay pull in at power on?
Yes
This test assumes that F1 and F2 have tested OK.
Yes
Replace Flashtube.
Microcontroller Failure.
Replace Digital Board.
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| Is DB DS1 red | Yes | Press DB SW1 |
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| pushbutton 1 sec |
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| and release. |
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| Indicator) lit? |
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| Power Supply Failure: |
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| Do DB DS2 | No | ||||||||
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| Replace Digital Board. |
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| Replace capacitor. If THVB |
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| DS1 High Voltage Indicator |
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| still does not light, or system |
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| after each step. |
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| flashes erratically, replace FH |
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| 1. | Replace Trigger/HV Card | ||||||||||||
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| T1 Transformer. |
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| 2. | Replace Digital Card | ||||||||||
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| 3. | Replace Flashtube. | |||||
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| 4. | Replace Trigger Transformer | |||||
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| Once problem is resolved, try | ||||||
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| restoring (one at a time), | ||||||
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| components replaced in previous | ||||||
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| steps. |
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| Check to see if problem is resolved |
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| after each step: |
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| No | 2. | Replace Digital Board. |
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| 3. | Replace K3 Relay. |
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| Check FH resistor pack |
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| closest to door). Replace if visually |
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| damaged. |
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| Rectification Failure: |
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| Replace Trigger/High- |
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| Voltage Board |
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Figure 4-2: General Troubleshooting – Flashhead Does Not Flash
Manual |