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Rhymeface
Tinkerer
Username: Rhymeface
Post Number: 1
Registered: 07-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, July 19, 2008 - 12:47 pm: | 
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Hi,
A while back I asked on here about replacing a torn off hotshoe on an Canonet G3 QL17.
I was told that the hotshoe off of a Canonet 28 would be suitable and cheaper as far as canibalising parts from it goes. So I found an old 28 on eBay for a pittance and got to work fixing up the G3.
Due to the contacts on the 28 hotshoe not lining up with the contacts in the top of the G3, I had to remove the whole contact unit from the 28 (involved unsoldering the blocks the body contacts are mounted on in each camera and swopping them over).
Just put the top back on, wound it on, depressed the shutter release and BAM!..............nothing.
Camera goes off fine but the flash isn't going off.
I've double checked the flash is working and it's also triggered when you mount or remove it from the hotshoe (assuming it's switched on and charged).
Does anyone have any ideas what might not be set up right?
All help appreciated. |
Rick_oleson
Tinkerer
Username: Rick_oleson
Post Number: 622
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, July 20, 2008 - 06:28 am: |
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Since you've unwired and rewired, it would probably be a good idea to check your connections.
The flash should not be triggering when you mount it into the shoe. This sounds like you may have a short from ground to the center pin in the shoe.
Connect an ohmmeter from the chassis to the large center pin in the hot shoe. The Ohmmeter should read infinity (no connection). Now open the shutter on the B setting and hold it open - the ohmmeter should go to zero.
If it doesn't, while still holding the shutter open, switch the ohmmeter lead from the large center pin to the smaller signal pin in the shoe and repeat. If the ohmmeter goes from infinty to zero now when you open the shutter, you have the wires reversed on the two pins.
Reversing the wires between the power and signal pins would cause the short and pre-firing that you describe, because there is very little resistance between the signal pin and ground, regardless of whether the shutter is open or closed. |
Rhymeface
Tinkerer
Username: Rhymeface
Post Number: 2
Registered: 07-2008
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, July 22, 2008 - 03:14 pm: |
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Thanks a lot Rick and thanks for the diagrams on your site. they helped a lot.
Just need to get me a ohmmeter now. |
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