Just imparting knowledge....
The flash light tube is NOT any the same as those
light bulb that you have in your torchlight.
Its a gas in alittle teeny weeny tube. Well
in must cases these tube will have no Gas leak
issues thus not the cause of the flash failing.
The flash circuitry is not that complex after all.
It has the basic 4 blocks.
1- The charging circuit (with a transformer which
less often will fail in any chance- Beware HIGH voltage)
2- The Storage Circuit( Just a large capacitor-Norm rated @320V or more)
Less likey to fail too.
3- The triggering circuit (Just a tweeny weeny capacitor
and the switch that you press or sync cord activated or
light activated when in slave). This circuit trigger the
ionisation of gas in the flash tube making it form a
close circuit and thus discharge the Large Capacitor which
gives you the BRILLIANT FLASH Pooff!!!!
- THIS IS THE CULPRIT
4- The Flash gas tube.
From my previous experiences, most cases, the failure is due to part 3.
For simple flash, its the Capacitor. A 20 cents capacitor. For slave
units this will be parallel switch to the "Test button" and this capacitor
Thus here is the symptoms when failure of PART 3 occurs.......
This is how you see:
- ON the flash
- If no signs of charging, change battery......CORNY!!!
- Listen to the Charging "whining sound" (for older circuit)
- Check if the light (charged light) is ON.
- If ON, it denotes that charging is okay. Part 1 works fine.
- If did not turn ON, then either the charge sense light blow
or charging circuit fail (PART2).- Verify by TEST flash if flash
can FIRE, then the charing lamp need to be replaced.
- Now , If charging is ON, then pressing the TEST BUTTON.
- If Flash cannot fire(The charge LAMP remains ON),
then the PART 3 circuit has problem.
- IF Flsh Cannot fire BUT Lamp GOes OFF, thn the Flash tube (Part 4)
needs to be replaced....
SO as a rule of thumb....follow the above steps to verify
before sending for repair. Else the shop guy will start to
blame the Flash Tube....and start charging high price.....
Know what you send in for.........