Canon T50: Beyond repair - the revenge of forgotten batteries

[Andreas Thaler]

I still had a Canon T50 in my box of repair projects.

On the outside, it didn’t look too bad.



A peek into the battery compartment gave me a bad feeling, even though there wasn’t anything dramatic to see there either. Dried battery electrolyte in the plastic housing and a greenish discoloration on the battery contacts. That should be cleanable from the outside.



However, I know from past experience that what you see on the outside of a battery that’s leaked is actually the better view.




So I took a look and knew as soon as I removed the top cover that this T50 wouldn’t make it onto my shelf.









The fumes from the battery electrolyte had risen from the battery compartment and settled on the underside of the top cover and on the surrounding circuit board.

Under the upper winding base plate, it looked like the crater of a sulfur volcano.

A veritable flower of electrolyte had formed on the black negative terminal of the battery. Evidently, the stuff had risen through the black battery cable and accumulated at the solder joint.

The battery electrolyte was liquid on the contacts of the mode switch. It looked just as bad under the rubber grip.

Even with a lot of effort, there’s nothing useful left to salvage here.

 

[Andreas Thaler]

But as with every section, there are valuable spare parts and insights to be gained. Among other things, I salvaged the DC/DC converter, as well as the mirror box and the shutter for further study.



The contaminated residue is disposed of.



Once again, we see just how cruel the consequences of forgotten batteries can be after all these years.

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A word of caution

Please keep in mind that you’ll be using highly flammable solvents for service work, and their fumes are harmful to your health. Soldering also produces fumes that should not be inhaled. Dangerous high voltages can be present when handling electronics, especially in conjunction with electronic flash units and mains. Therefore, familiarize yourself with the safety regulations beforehand and ensure your safety. Depending on the activity, protective gear may be advisable.

All information provided without guarantee and use at your own risk.

Acknowledgments

Without the work of Master Larry Lyells, in particular, we wouldn’t have the detailed technical information we need today for service/repair of SLRs.

The SPT Journal and The Camera Craftsman, which he helped shape significantly as an author, and which contain all the necessary information and instructions are available for a fee through Learn Camera Repair.

We owe our access to them to Eugene Pate, the founder of Learn Camera Repair.