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Using Magic Lantern => Hardware and Accessories => Topic started by: handbanana on August 10, 2012, 08:17:21 AM

Title: Question on fixing "broken" mic input on 550D (And how ML helps "fix" it)
Post by: handbanana on August 10, 2012, 08:17:21 AM
Hey everyone! So I've had a 550D since it came out. I've been wanting to add a 2nd cam to my setup, but as a recent college grad money has a way of disappearing even faster than it appears. Anyways, the 550D has been great and has been put through a lot.

About 4+ months ago, I noticed that my mic input was a lot looser than it used to be. Gone was the "click" you hear when inputing a microphone input, the same kind of click you hear when plugging in headphones to a laptop, for example. I found this quite unsettling,given how much I love my camera, but I figured "hey is still works fine besides it being slightly looser." I found that putting a small piece of scotch tape around the base of my Radio Shack XLR-Headphone jack adapter made everything extra snug and more or less solved the issue.

Fast forward about a month later and I find that my internal mic no longer records. If I plugged in the external, everything was fine, but the internal no longer recorded audio. Then I noticed that when I set ML to "internal mic" it works fine, but when set to auto int/ext that it defaults to the external mic automatically. So now not only does my camera not have a loose input, but it doesn't even switch between the inputs if the external were to become unplugged. I've given it a good testing where I shake it about a bit and 90% of the time the external stays in (and the 10% it does are time that it may well have come unplugged on a new camera) but I no longer have that safety net of it at least defaulting to the internal. :/

For most of my work, the internal setting in ML saves me by letting my camera use the internal mic that in vanilla firmware would be unusable, and the audio is fine for matching up either external audio recorded by someone else, or to a music track (for music videos).

Has anyone had a similar situation and is there something I could do to fix this? Or if I had to get it repaired (at almost 2yo I'm sure the T2i is OOW) how much would something like this run me? Ideally, I'd be able to just spend any money I would on repairs on a new body later this year, unless the repairs were relatively cheap.

Which brings me to another point, the int left/ext right setting. This would be ideal if it worked (int mic for safety and external mic plugged in). But my mic only records to the left channel. And barring running some extra cabling to switch the channels, how can I get my mic to record to the left and the internal to the right? I think that this would make more sense since I imagine most other mono mics doing the same and recording to the left.

Thanks everyone :)
Title: Re: Question on fixing "broken" mic input on 550D (And how ML helps "fix" it)
Post by: 1% on August 10, 2012, 08:50:21 AM
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I found that putting a small piece of scotch tape around the base of my Radio Shack XLR-Headphone jack adapter made everything extra snug and more or less solved the issue.

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So now not only does my camera not have a loose input, but it doesn't even switch between the inputs if the external were to become unplugged.

Uhm... it sounds ;) like your input jack IS broken... just not all the way. Maybe only 1 leg of it? Or a cold/cracked solder. Or metal fatigue inside the jack itself?

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Radio Shack XLR-Headphone jack adapter

Heavy XLR connector + cable always (often?) hanging down putting strain on the jack?

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how can I get my mic to record to the left and the internal to the right?

L-int, R-ext isn't an option for 550d? We have it on 600d.

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unless the repairs were relatively cheap.

Canon may fix it cheap but who knows. The price will probably depend on how far the audio connector is buried in the camera and how much the tech has to take apart. Canon also aren't too keen on soldering/used parts so a 3rd party may help here so they're not replacing a whole $$$ board. I have not looked at the service manual yet so not sure.
Title: Re: Question on fixing "broken" mic input on 550D (And how ML helps "fix" it)
Post by: handbanana on August 10, 2012, 09:12:40 AM
Hey thanks for the reply!

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Uhm... it sounds  like your input jack IS broken... just not all the way. Maybe only 1 leg of it? Or a cold/cracked solder. Or metal fatigue inside the jack itself?

Yeah it's not a matter of wether it's broken, just a matter of how. :/ And obviously you know more about this stuff than I do, haha - the crappy part is that it interferes with the internal mic's auto switching.

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Heavy XLR connector + cable always (often?) hanging down putting strain on the jack?

I usually wrap the xlr around the mouth I have, and would then have it come from above so it wouldn't really be pulling on it, but I guess this was still never as simple as having a mic with a lighter cable built into it... I used a right-angle adapter before that I had lost (just found it!) that would face up or down but I used a regular straight one for a while 0 I was using the straight one when it broke.

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L-int, R-ext isn't an option for 550d? We have it on 600d.

It is an option, but it wasn't working because my mic is a mono mic and would record to the left channel by default. In L-Int; R-ext, the right channel was still empty because the mic defaulted to left. I saw an explanation online but it involved a whole slew of extra stuff just to switch channel

However, I found my right-angle adapter, and that one converts my mono signal to stereo! So now on EXT it records to both channels, and in L-int, R-ext, I now have the internal on the left and external on the right (So I learned that this does work but only if you have a stereo signal coming in) - I figure this should be the best fix for the time being for recording audio with a mic, I will always have an uninterrupted internal signal as a backup. Now I just need to remember to switch it to this from "internal mic" mode when I use the external.

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Canon may fix it cheap but who knows. The price will probably depend on how far the audio connector is buried in the camera and how much the tech has to take apart. Canon also aren't too keen on soldering/used parts so a 3rd party may help here so they're not replacing a whole $$$ board. I have not looked at the service manual yet so not sure.

Yeah, I figured the 3rd party route would be cheaper, but again, that's money I can use for a new camera, or to pay bills, credit card, student loan, etc :/ And something about a random camera repairman in Miami just doesn't convince me, hahaha.

Thanks so much for your reply!  :D
Title: Re: Question on fixing "broken" mic input on 550D (And how ML helps "fix" it)
Post by: 1% on August 10, 2012, 09:22:20 AM
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regular straight one for a while 0 I was using the straight one when it broke.

I did this too, only the camera fell over and shattered the connector + pushed the pieces inside. I was in warranty and it wasn't a DSLR so it got fixed after some bitching.

After that I bought a preamp.

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And something about a random camera repairman in Miami just doesn't convince me, hahaha.

You need a shop that does component level stuff, not a random guy. Rip flexible film style connector and its curtains. You're better off waiting like you are and getting  a new body or living with it till it goes the rest of the way.
Title: Re: Question on fixing "broken" mic input on 550D (And how ML helps "fix" it)
Post by: handbanana on August 10, 2012, 09:45:56 AM
A preamp would be nice if it clicked when I inserted. I think I'll just wait I guess. Oh and to clarify, the adapter only made it stero because the 2nd adapter wasn't plugged in all the way (even tho these are 2-lines and are supposed to make it stereo :/)

Maybe you know a little more about this, when plugged in all the way I get a nice clean signal on the left. When slightly unplugged like it was before, it gives me a stereo signal that sounds fine on the right channel in l-int/r-ext (when i isolate is in premiere), but sounds like crap when stereo in premiere (recorded in ext mode) - BUT using fill right and fill left both sound fine...

I found a short rca-quarter adapter cable and xlr-rca adapter that is another way to send the signal only to the left or only to the right, which I guess is the safest option? Too bad its so damn short though >_<
Title: Re: Question on fixing "broken" mic input on 550D (And how ML helps "fix" it)
Post by: 1% on August 11, 2012, 12:21:32 AM
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Maybe you know a little more about this, when plugged in all the way I get a nice clean signal on the left. When slightly unplugged like it was before, it gives me a stereo signal that sounds fine on the right channel in l-int/r-ext (when i isolate is in premiere), but sounds like crap when stereo in premiere (recorded in ext mode) - BUT using fill right and fill left both sound fine...

If you look at a stereo plug, the "channels" are separated by a thin ring of plastic. Plugging it in partially can short it to "stereo" or 1 channel or whatever depending what is making contact with what. The crappy partial connection probably sounds shitty.
Title: Re: Question on fixing "broken" mic input on 550D (And how ML helps "fix" it)
Post by: Francis on August 14, 2012, 05:57:01 PM
As for getting it repaired by Canon, ask them how much it costs. Contact their service department. From what I understand repairs are relatively cheap and turnaround times are fast. A new shutter/mirror box costs $150-200 depending on the model, so I can't imagine a mic input being very expensive at all.
Title: Re: Question on fixing "broken" mic input on 550D (And how ML helps "fix" it)
Post by: Led on August 16, 2012, 05:24:35 AM
The mic socket has 3 lugs that are soldered to the circuit board inside the camera. It's most likely one lug has broken, and it could probably be fixed by resoldering rather than needing to replace the socket. The trick is getting the camera apart to get access to the circuit board.
I had a look and there are a few small screws around that point, but it's hard to say without pulling it apart.
If the board can be got to it would be a rather simple fix to solder the socket again, not expensive at all.
Having said all that, you could get it apart and find the actual socket has cracked, which would mean replacing it. If you bought the socket from an electronics supplier like Digikey, it would cost about $2 for the part.