Help, 50D wont turn on! Did I fry the cameras electronics?

[aesco48]

<p>Last week I made a power supply for my 50D using an automotive DC to DC power supply (7.5v 1,000 mA) and made a wired battery by gutting out an old battery. I tested it at home using my Jeep and it worked perfectly. This weekend I was 4 days into the Egyptian Sahara desert, had a beautiful sky and an abandoned British WW2 truck in front of me . Had used the camera during the day, night came and I went to do my first ever session of Stair Trail photography and the camera did not turn on with the power supply or after with fully charged battery.<br>

Have tried letting it sit over night with the battery and button battery out and nothing works. Nothing when I connect it to the computer.<br>

The only thing I can think of is that the power supply polarity was reveresed... Even though I triple checked it before putting tape over the connection.</p>

<p>Any ideas? If the polarity was reveresed... How bad is it?<br>

Plan is to send it to one of the German Canon service centers since there are non in Egypt.</p>

<p>Good news is I got the pic!</p>

[bobatkins]

<p>I don't know if the camera has protection against polarity reversal. It doesn't need it because you can't put the battery in backwards. If it doesn't and if you did reverse polarity, you may well have fried it. Also, if your DC to DC converter isn't stabilized or failed to provide the correct voltage, that may have fried the camera.</p>

 

<p>I think the stock Li-ion battery is nominally 7.4v, so 7.5 volts should be fine - if it really was 7.5 volts all the time, with no spikes to higher voltage.</p>

 

<p>Canon will tell you. We can't help. Sounds like you did indeed fry it. Repair cost will depend on just how much of it you fried.</p>

 

<p>I made my own EOS battery adapter back in the days when I was shooting film. It worked fine, so in principle, if you are very careful about voltage and polarity and don't screw up, your scheme should work fine.</p>

 

<p>You can buy AC adapters with a dummy battery connection. <a href="http://www.bhphotovideo.com/c/product/590445-REG/Canon_3351B002_ACK_E6_AC_Adapter_Kit.html"> Canon ACK E6</a>. Don't know if they have a DC version for the 50D

[PuppyDigs]

<p>Reversed polarity will indeed fry it and fry it good. Now you have a good excuse to buy a 5D3...</p>

[Marcus Ian]

<p>While 7.5v won't hurt it, reversed polarity certainly could have, in which case you are in for a heckuva repair bill (if they'll fix it). Of course it could also have been your power supply. A cheap DC -> DC is often simply a resistor, NOT a voltage regulator, which means variations of supply voltage cause variation in delivered voltage. In a static rich environment like the desert, a vehicle's electrical system is rife with voltage spikes. Even the Radio can feedback into the power system. The vehicle's battery usually acts as a damper, but spikes are exactly that, spikes. and depending on where the 12v power is tapped off the electrical system, the power may be isolated from the battery (to prevent noise from <em>entering</em> the loop). Of course even a voltage regulator won't always prevent that... it all depends on the nature of the spike, duration, components, etc.</p>

<p>Of course I don't know what you did precisely, but I would guess that you successfully killed your camera. I would have gone w/ a cheap BG + 2 (or more) batts instead. that's a lot of battery life, plus, they don't usually kill the camera... ;-)</p>

 

[peter_j2]

<p>You most likely reversed the polarity and damaged the camera's electronics. If you place your nose near the battery chamber, can you detect a burnt odour? </p>

<p>By accident, I reversed the polarity when installing two double A batteries into a Paul C. Buff Cybersync Receiver CSRB. Within 5 seconds I could smell something burning. I quickly removed the batteries from the unit. The batteries were warm to the touch. There was also a mild burnt smell from the CSRB. Luckily, there was no damage and the smell eventually went away. </p>

[frank_skomial]

<p>...and reversed polarity is so easy and inexpensive to prevent, could be as simple as installing a single diode, I wonder why they do not have it ?</p>

 

[aesco48]

<p>The power converter i bought was a "Regulated switching power DC/DC converter" with an input range of 12-24V, output of 1.5,3, 4.5, 6, 7.5, 9, 12V and a max current of 2,000mA. I checked with a multimeter the voltage and polarity when I 1st tested the setup before connecting it to the camera. Voltage switch is where it needs to be (needs a screw driver to be moved) so it did not change by itself.<br>

Is that considered a cheap power supply? It was about $20 USD.... </p>

<p>On that night before connecting it to the camera I made sure the plugs polarity was right!<br>

I will give the camera a smell this afternoon!</p>

<p> </p>

[aesco48]

<p>No burnt smell...</p>

[Marcus Ian]

<p>Andres, since it is a 'variable' output DC-> DC converter it almost certainly utilizes resistors to drop the voltage, as otherwise, it would require a voltage regulator for every specific output voltage, Most likely the converter uses a small rotary switch to send the current through the appropriate resistor to the 'output' (at the target voltage) Taking it apart will answer that question for you. Some of those use a variable resistor, but those are less common, and vastly more unreliable. I have yet to see a 'regulated' output variable DC-> DC convertor used in such applications.</p>

<p>No, I don't think it's likely that you reversed the polarity (especially since you double checked). I think it's far more likely that a static discharge (due to dry desert air, and cables strung across the inside of running cars) caused a spike in the feed voltage, and fried your camera. Remember, even the static discharge you get from a doorknob is 3000+ volts, and you plugged that into a camera designed to run on 8v. I get shocked all the time in dry air because the car is often insulated from the ground by 8+" so if you got out of the car, carrying the camera, plugged in, then the voltage would have gone straight from the chassis through the wire, the camera, you and to ground - you may not have even felt it. <br>

Based on your description, I think that almost certainly, an ESD is what killed your camera, facilitated by you plugging it in (remember, electricity follows the path of least resistance).</p>

[bob_sunley]

<p>I'd guess it was using an LM317 or similar, inexpensive and easy to control with fixed resistors or a pot.</p>

<p>But a good static discharge can be 15kv, so that could have easily fried your camera. Dry desert air is really bad for static discharges, even worse that cold winter climates. :(</p>

<p> </p>

[aesco48]

<p>Guess I am opening up the converter this afternoon... It definitely stated "regulated" on the converter... So sad!</p>

[aesco48]

<p>This is the web page i got most of the info to make my power supply: <a href="http://theamusing.com/photography/power.html/">http://theamusing.com/photography/power.html/</a></p>

<p>I just now noticed that the DC to DC converter I bough is also one of the ones recommended on this page: <a href="http://www.powerstream.com/dc6.htm">http://www.powerstream.com/dc6.htm</a></p>

[bob_sunley]

<p>Andres, you could test the power supply by connecting a small automotive light bulb to it and measure the voltage before you take it apart.</p>

[Marcus Ian]

<p>Yeah, based on the page you posted, My <em>assumption</em> is that the voltage is resistor driven, especially since the 'efficiency' rating is 54 to 78% (! ! !) <em>way to low</em> for a properly voltage regulated device.</p>

<p>Keep in mind that the term 'regulated' is often misused, implying that the device regulates power, when often all it does is <em>tap</em> regulated power. IDK, I don't have one to take apart, but by plugging the camera directly into the vehicle, <em>regardless</em> of the insulation/regulation, the ESD could have come through on the ground side (which is usually a straight wire, and carries the potential static buildup of the ENTIRE vehicle frame).</p>

[aesco48]

<p>So here is the insides of the converter... :)</p>

<p><img src="https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/s720x720/419810_10100431690899958_18709104_47929807_1181152608_n.jpg" alt="" width="533" height="720" /></p>

<p><img src="https://fbcdn-sphotos-a.akamaihd.net/hphotos-ak-ash4/s720x720/423368_10100431690939878_18709104_47929809_613854404_n.jpg" alt="" width="534" height="720" /></p>