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Old Jul 30, 2004, 8:45 PM   #1
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I have a C-5050 and an older Metz 45 CL-3 flash. Using a SCA320 I can use the flash on the C-5050 in manual mode; the adapter is then connected to the flash via a cord. One day, while I had the flash switched ON (and charged up to fire), the digicam switched OFF and the adapter mounted on the hot shoe but the cord not connected to the flash. So, I plugged the cord into the flash and suddenly that triggered the flash light. However, since then the flash has never worked! When I remove the batteries and insert them after a while to ensure that the capacitor is discharged, I can hear the usual "charge-up-sound", but the green light indicating that the flash is ready to fire never lits and the flash does not respond when clicking on the Test button.
I have opened the flash (what a huge capacitor!) but cannot smell or see any defect electrical component. I haven't disassembled the flash further than removing the plastic cover as I don't know what I'm looking for. My question is the cause of the flash getting broken by connecting the cord to the flash while it's switched ON, and how - if possible - I can fix it. Thanks!

Jack
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Old Jul 30, 2004, 10:26 PM   #2
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The symtoms are like when the trigger remain close (shorted) after the flash burst.

You can first , if you didn't do it already, test the flash with no cord connected, to make sure that no connector pinis shorted . It should charge up and able tofirewith the test button - then the fault is probably the SCA. If not , the fault is within the flash. Unfortunately, although I own 2 45-Cx Metz, I don't have any schematic, so I can't help further,
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Old Jul 31, 2004, 8:38 PM   #3
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Hi KCan, thanks for your reply.I, however, have tried your suggestion without positive result. I guess there's nothing to do but disassemble it to pieces. :evil:
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Old Jul 31, 2004, 9:37 PM   #4
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OK, then something bursted inside the flash . It's probably the trigger SRC (triggering circuit) , or the quench SRC (flash cut off circuit)

If you know a bit in electronics you can try 2 things:

The academic approach: You retrace the whole schematic then you have 50% of the work done, but it takes time :roll:

The quick (but less noble :-)) approach: you identify all the semiconductors (especially the 3 legs ones) and test every one, since the fault is probably an SRC (my opinion)

Good luck :?
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Old Aug 1, 2004, 11:58 AM   #5
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Hi KCan,
sounds like there are two things I can try to get the flash working again. I'm no expert in electronicsbut I have basic knowledge.

Just one more question: What does SRC stand for and what is its purpose? Thanks in advance!
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Old Aug 1, 2004, 12:14 PM   #6
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sushiboy,

I am sorry, it's SCR (typo) = silicon controled rectifier. You can search on the net for how to check them . in short , it's used to conduct the current when it is ":triggered" with a signal at the gate (the 3rd leg). then it conduct until the voltage on the 2 other legs drop down, nothing can stop that flow (the curent flow maintain the conductivity) when it stop conducting, you can build uo the voltage and trigger it another time.

There are many more "evolued" semiconductor of that familly after the SCR, but Metz use to use very classical circuit, that's my guess only.
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