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"Memory card error" for some SD cards

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Offline ahull

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Re: "Memory card error" for some SD cards
« Reply #20 on: 23 / November / 2014, 08:53:07 »
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Quote from: alvm on 22 / November / 2014, 17:16:18

I'm using NoName AC adapter - WP-AC04315V


Google suggests from the part number it looks like this. I have a couple of identical ones in my office, If I get a chance I might fire one up and stick the scope on the output, or even rip one apart to see how dodgy it looks inside.

I don't think I have ever used them, as I only bought them for the dummy battery they come with.
« Last Edit: 23 / November / 2014, 08:54:46 by ahull »
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Offline waterwingz

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Re: "Memory card error" for some SD cards
« Reply #21 on: 23 / November / 2014, 10:27:18 »
Quote from: ahull on 23 / November / 2014, 08:45:30
My guess is that there is some sort of high frequency noise getting through to the camara from the PSU,
If that was the case (and it may well be) then you would expect random lockups - not just when writing to some SD cards.  I have several of these sort of supplies appear to work and then crash when I actually took a shot.  Replacing the electrolytic capacitor on the outside with something a little bigger and higher quality solved that. My conclusion is that the cheap ones just can't supply enough instantaneous peak current when it's needed.
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Ported :   A1200    SD940   G10    Powershot N    G16
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Offline ahull

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Re: "Memory card error" for some SD cards
« Reply #22 on: 23 / November / 2014, 11:14:06 »
Quote from: waterwingz on 23 / November / 2014, 10:27:18
Quote from: ahull on 23 / November / 2014, 08:45:30
My guess is that there is some sort of high frequency noise getting through to the camara from the PSU,
If that was the case (and it may well be) then you would expect random lockups - not just when writing to some SD cards.  I have several of these sort of supplies appear to work and then crash when I actually took a shot.  Replacing the electrolytic capacitor on the outside with something a little bigger and higher quality solved that. My conclusion is that the cheap ones just can't supply enough instantaneous peak current when it's needed.

I guess it depends what the failure mode is, if it is caused by brownout on load, then moving the mechanism should cause a crash, but if it is due to a particular frequency of noise, then only certain operations might be affected. In other words, if we have a load of junk on the supply rails at a critical frequency to impede reliable SD card operation, then SD card operation might be one of the few things affected. A 0.1uF polyester cap and a couple of 100uF electrolytic caps across the supply might be all it needs, but without knowing the nature of any interference, that would be just a guess.   
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Offline alvm

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Re: "Memory card error" for some SD cards
« Reply #23 on: 23 / November / 2014, 13:40:15 »
To waterwingz and ahull - a camera works fine without chdk! And why Sandisk SD card works without any errors? What kind of differences are between Sandisk and other SD cards?
« Last Edit: 23 / November / 2014, 13:46:03 by alvm »
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Offline alvm

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Re: "Memory card error" for some SD cards
« Reply #24 on: 23 / November / 2014, 13:56:59 »
Quote from: srsa_4c on 23 / November / 2014, 07:00:23
Quote from: alvm on 23 / November / 2014, 02:10:10
When camera do it? There aren't any messages at start.
I mean, if you see "Memory card error" on screen, the camera already thinks that the card doesn't work and will not attempt to read or write it.

There aren't any errors at start a camera, I see last image on screen - so SD card is readable. The error appears only after shooting.

Quote from: srsa_4c on 23 / November / 2014, 07:00:23
Quote
Second method (long press) doesn't help.
It's a different issue then.

Since you have a computer connected to the camera's UART, try capturing and comparing the camera log (with ShowCameraLog) when the camera starts in playback mode
- with the battery
- with external power
make logs without and with starting a diskboot. Perhaps the difference shows up in the logs. Use one of the problematic cards for these tests.

You could also dump the lower part (between 0x1900 and MEMISOSTART) of RAM (I think drysh has a command to do it) and compare it.

Thanks, I'll try do this.
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Offline waterwingz

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Re: "Memory card error" for some SD cards
« Reply #25 on: 23 / November / 2014, 14:40:09 »
Quote from: alvm on 23 / November / 2014, 13:40:15
To waterwingz and ahull - a camera works fine without chdk! And why Sandisk SD card works without any errors?
As I've said at least twice now, when CHDK is loaded the "low battery shutdown" threshold point might be higher - causing the camera to shutdown if the power supply droops.  The same droop might not be a problem without CHDK loaded.

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What kind of differences are between Sandisk and other SD cards?
Maybe some cards draw more power when being written to?  Or if the writes are faster, the overall power consumption goes up?

Update : are you also saving RAW/DNG ?  That would draw even more power after every shot.
« Last Edit: 23 / November / 2014, 14:42:44 by waterwingz »
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Ported :   A1200    SD940   G10    Powershot N    G16
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Offline alvm

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Re: "Memory card error" for some SD cards
« Reply #26 on: 23 / November / 2014, 15:23:00 »
Quote from: waterwingz on 23 / November / 2014, 14:40:09
As I've said at least twice now, when CHDK is loaded the "low battery shutdown" threshold point might be higher - causing the camera to shutdown if the power supply droops.  The same droop might not be a problem without CHDK loaded.

Camera in my case doesn't go to shutdown, only shooting and writing to SD card are blocked. Other operations are still available. 
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Offline waterwingz

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Re: "Memory card error" for some SD cards
« Reply #27 on: 23 / November / 2014, 15:35:38 »
Quote from: alvm on 23 / November / 2014, 15:23:00
Camera in my case doesn't go to shutdown, only shooting and writing to SD card are blocked. Other operations are still available.
Sorry - I missed that distinction.  So it works without CHDK on battery or AC power, and it works with CHDK on battery.  It is just the combination of CHDK and AC power that causes error messages when it tries to write to some SD cards? 

Might still be a low voltage threshold thing locking out card writes.  I don't have a better suggestion.
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Ported :   A1200    SD940   G10    Powershot N    G16
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Offline alvm

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Re: "Memory card error" for some SD cards
« Reply #28 on: 23 / November / 2014, 15:39:23 »
Quote from: waterwingz on 23 / November / 2014, 15:35:38
  It is just the combination of CHDK and AC power that causes error messages when it tries to write to some SD cards? 

Yes, you are right.

I've tested one more AC adapter 4.2V/2.5A. Result is the same.

Quote from: waterwingz on 23 / November / 2014, 15:35:38
Might still be a low voltage threshold thing locking out card writes.

Perhaps all critical values are shifted depending on power voltage. But Sandisk...
« Last Edit: 23 / November / 2014, 15:42:20 by alvm »
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Offline reyalp

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Re: "Memory card error" for some SD cards
« Reply #29 on: 23 / November / 2014, 16:38:20 »
Quote from: alvm on 23 / November / 2014, 13:40:15
To waterwingz and ahull - a camera works fine without chdk! And why Sandisk SD card works without any errors?
FWIW, I've seen PSU problems in PCs that would repeatably fail in some particular code while otherwise seeming stable. So it's definitely weird, but I wouldn't say it's entirely implausible.

That said, CHDK being at fault somehow is also plausible.
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What kind of differences are between Sandisk and other SD cards?
Different controllers having different levels of tolerance isn't too surprising. I would expect Sandisk to be high quality and probably more tolerant of marginal inputs than the cheap no-name brands. OTOH, Transcend and Kingston aren't exactly bottom of the barrel ether.
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