Yashica Electro 35 GT, 'Bulb'-only shutter problem

[chanzhf]

Greetings to all seniors and experts here.

I will like to seek some advice regarding a Yashica Electro 35 GT that i have. Cosmetic wise, perfect. Function wise, a little issue.

Putting in a battery, the camera only functions in bulb mode be it the dial selector is at 'B' or 'AUTO'. To be more precise, the shutter will not close until i let go off the shutter release button. Along with that problem is that the 'Slow' arrow light always light up when the shutter release is depressed, regardless of lighting and apertures.

I did some intensive readings over at photo.net, classic camera repair forums, and yashica-guy. The common solution seem to be a POD or some adjustments at the rod at the base plate. Tried them both, fitted in a new rubber pad but i still dont see a difference before/after.

Now here is the problem. I wish to attempt to fix them myself and in the process learn more about vintage cameras.

I brought them to 2 local technicians to have a look to maybe seek some advice. The first one refuse to let me know what the problem is, but he claims he has encountered many of such similar issues is and said he'll repair it for quite a hefty amount, about US$150. The second technician diagnosed it as an electronic issue, and said he'll try to change the circuit board 'A' with his own parts. He quoted similar repair fees.

Hearing these, i would like to seek another opinion from the members here at rff. Are there any methods i can try out to rectify the so called permanent 'Bulb' mode and the permanent 'slow' arrow light? i have another yashica 35 gsn which has a broken lens and focus ring. If there were similar parts that i can salvage from there, please do kindly advise.

Thanks for your time and response.

 

[btgc]

Hello here,
You can repair it yourself (pad of death) or ask RFF member b1bmsgt for his quote.

 

[monopix]

I already answered you over on Kyphoto and I still say the problem is likely to be a problem with the switches. If S1 is open circuit, for instance, you'll get the symptoms you describe. But there could be other causes. You need to remove the lens plate and clean all the contacts and then adjust the release rods as a starting point. If you still get problems then a quick probe around the circuit should show up where the problem is.

I don't think it's the capacitor (answering your question over on Kyphoto). A faulty capacitor would cause the camera to operate in B mode but it wouldn't cause the red light to come on.

 

[chanzhf]

I already answered you over on Kyphoto and I still say the problem is likely to be a problem with the switches. If S1 is open circuit, for instance, you'll get the symptoms you describe. But there could be other causes. You need to remove the lens plate and clean all the contacts and then adjust the release rods as a starting point. If you still get problems then a quick probe around the circuit should show up where the problem is.

I don't think it's the capacitor (answering your question over on Kyphoto). A faulty capacitor would cause the camera to operate in B mode but it wouldn't cause the red light to come on.

Hey there, thanks for the help. I've never asked anything regarding yashicas over at kyphoto before, think u've got a mix up.

In anycase, appreciate your answer. I've tried searching kyphoto for the thread you mentioned but see nothing similar. What solution do you suggest i can try to test your hunch? I have opened up the camera top plate(it says made in japan) and all soldering points are extremely clean and well soldered. More specifically, i hope you dont mind letting me know what do you mean by 'quick probe'? Not exactly fantastic with electronics.

great thanks!

 

[monopix]

Ah, sorry. Just there was a guy over there with the same problem. The thread is at http://www.kyphoto.com/classics/forum/messages/2/20114.html?1288122398

Not sure there is any quick way to check my theory. I think you need to remove the lens plate to get access to the switch PCB and the contacts on the release rods and clean everything. It's where I've seen problems before and, depending on which contacts aren't making, the symptoms can be varied. An open circuit on S1 or along the CDS cell wiring would cause the symptoms you have and that's where I would start.

There's a service manual which includes circuit diagrams on my Scribd site at http://www.scribd.com/doc/19302555/Yashica-Electro-35-Service-Manual which may help.

By 'quick probe' I meant basically to use a meter to check around the circuit to see what's happening. It's a pretty simple circuit so shouldn't be too difficult to fault find but you will need a volt meter of some sort. You can check a fair bit from the top without removing the lens plate so might be worth trying that first. Have a look at the circuit in the manual. Does it make sense? If not, I might be able to describe a few specific points to look at. It's a while since I worked on one though.