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Cooltouch
Tinkerer
Username: Cooltouch
Post Number: 215
Registered: 01-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, September 17, 2012 - 11:40 am: | 
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I just bought a used Metz 45 CT-4 and have run into a problem where it won't fire at all. When the power switch is switched "on" I hear the capacitor whine as it's being charged, and a moment later, a light illuminates. Which light that illuminates depends on where the dial is set: Auto, TTL, Manual, Winder. After it's charged up, it doesn't matter whether I push the "test" button or try tripping it from a camera's PC connector. Neither way works. I even tried it out on three different cameras just to be sure that one of the cameras wasn't also a problem. I also tested the Metz's sync chord for continuity, and it is good.
I have repaired flashes before, so I am very aware of the hazards involved with getting close to a charged capacitor. If I have to open it up, I plan to run leads from the capacitor to a piece of pipe I have sunk into my backyard that I can use to ground it out. So please, spare me any obligatory urges you may feel about cautioning me about the flash capacitor, okay? I'm well aware of it.
I want to know if there is a specific area or component that I should focus on as a likely culprit. I'm hoping it is something physical that can be repaired, say a loose or broken wire, cold solder joint, etc, because I'm pretty much a neophyte when it comes to electronics. If a circuit has gone bad, I won't have any idea of how to test for it. I do have a DMM, though, so if you know what I should look or test for, I'm open to this type of suggestion also. |
Finnegan
Tinkerer
Username: Finnegan
Post Number: 218
Registered: 09-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, September 17, 2012 - 08:29 pm: |
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I'm no expert but all electronic flashes have some sort of "trigger" switch (or "trigger" capacitor?) that dumps the energy of the main capacitor into the bulb. Ok, I asked the electronics guy here and was told it is called a triac. |
Cooltouch
Tinkerer
Username: Cooltouch
Post Number: 216
Registered: 01-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, September 18, 2012 - 04:06 pm: |
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Thanks for the feedback, Finnegan. I wonder how commonly a triac goes bad? I guess I'm just gonna have to open it up and poke around. With rubber-handled tools.  |
Olympfix
Tinkerer
Username: Olympfix
Post Number: 55
Registered: 05-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, September 19, 2012 - 04:47 am: |
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If you touch the outside and inside terminals of the synch cord with a paper clip or similar, and can see a tiny spark, it means the flash tube is kaput. I imagine there are still spares somewhere. The repair is quite straight forward. |
Cooltouch
Tinkerer
Username: Cooltouch
Post Number: 217
Registered: 01-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, September 20, 2012 - 10:18 am: |
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Thanks for this. I just tested it. No spark, tiny or otherwise. I'm not really surprised by this. This 45 CT-4 is actually in excellent cosmetic condition with no signs of wear to speak of. I'm wondering if there is a component that is likely to go bad just from the flash sitting for a long period of time. I have a Vivitar 285 that is dead, apparently from sitting for too long -- won't take a charge or reform the capacitor even after being hooked up to A/C power for days. But I don't get the capacitor whine when I turn it on, though. Hearing that whine gives me hope that there's just some component somewhere in the CT-4's mix that's failed or been disturbed. |
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