[POSSIBLE] bypass Write Protect SD for EOS550D

[burningreggae]

Hello!.
my SD-Slot write protect pin seems to be broken.
the 550d always say "write protected" with every card now. (so my beloved cam is dead now, 2 month out of warranty, and i'm too poor to buy a new one). reading is still possible.

is it theroretically possible to ignore this indicator with ML?.
maybe there is just a if (write_protect ) return statement in the file operations..


Thanks for helping!.
burning

[a1ex]

No thanks, I've broken one card while investigating this.

[Francis]

Sounds like a relatively cheap repair via Canon.

[burningreggae]

@a1ex: Thanks for responding!.

Do you mean, there exist some code which can be patched at runtime, so that write operations are possible, but the electronic fried your sd-card ( how should that be possible ?!?! ) and you don't want to look further.

or there is no entry-point in the code-base where the write-pin state is visible ( is it io-port communication or memory mapped?).

I know i have to study the source, but i'm just starting. but i need a working camera and i'm asking before i disassemble the 550d to short-cut the write lock..

thanks burning

[burningreggae]

Thanks Francis!.

but what is cheap?. 3 cent for a broken wire, yes. but not >300€ for nothing.
I wish the mechanic switch would be removed from every sd-reader. it's a design regression for hardware and just a stupid software flag..

thanks burning

[Walter Schulz]

Not tested: You may have success shortening WP and CD pins.
http://www.sparkfun.com/datasheets/Prototyping/SD-Socket-PP-19607.pdf
If you are not familiar soldering such items: Ask someone who does. It's not recommended to try this without proper equipment.
You have to disassemble the cam.

Ciao, Walter

PS: Wondering why it may cause hazard to change code to use CD pin instead of WP pin as input. But I'm not a programer.

[burningreggae]

Thanks Walter!.

Is this the exact SD-Reader for the EOS550D, the SD-Socket-PP-19607.pdf?
So i can assume that contacts must be closed to unlock?. Switches Circuit Schematics says so
but i can't see what exact must be closed. Maybe you can help me? ( I'm just a programmer;-)

I'm asking because i first want to try from outside to bend the signal-wire to some position (open/closed), nothing worked yet.

yes i need somebody with equipment and high-voltage experience.
Anybody around Vienna/Austria?. Help would be appreciated but i can't pay that much

and that was my initial question: Can the related CD/WP combinations be manipulated/ignored by ML, or are they hidden in the canon rom. ( I have to learn ML and the Canon now. If the ROM FileIO is executed in a Shadow-Ram, and there is No Memory Protection, it maybe can be patched at runtime..)

Thanks, burning!

[Walter Schulz]

Is this the exact SD-Reader for the EOS550D, the SD-Socket-PP-19607.pdf?

I'm sure it is not! But if you show the data sheet to a solderer he will be able to determine where the pins are.

but i can't see what exact must be closed.

Just show the data-sheets to the solderer and tell him to connect WP to CD.

I'm asking because i first want to try from outside to bend the signal-wire to some position (open/closed)

Just don't. This is where hazard lies within.

yes i need somebody with equipment and high-voltage experience.

High-voltage? 5 Volts is not high voltage.

Ask for help in a german speaking forum related to electronics like http://www.mikrocontroller.net

Ciao, Walter

[1%]

Maybe the switch is just gummed up. I'd check before doing something drastic like soldering it.

[burningreggae]

Thank for all you anwers!.

@walter:
I thought the internal Flash has 300V and according to some youtube videos at least 3 platines must be disassembled before the sd-slot can be dismounted (and the risk is too high for me for accidently touching the flash circuit )

thanks burning!

[Walter Schulz]

Good one!
This is a flash with internal 300V (or more):

(Source: Wikimedia)
and the thing on the top of the camera is a flash device, too.

"Flash memory" works at a much lower voltage level (18 V or less).
http://de.wikipedia.org/wiki/Flash-Speicher#Bezeichnung_und_Name

And, please: Don't mess up the pins on your own. Stay away, just don't. Not because you are running for Darwin Award but the pins are not very forgiving if treated the wrong way.

Ciao, Walter

[a1ex]

Update - after encountering this error a couple of times in QEMU, noticed the SD write protect issue can be fixed with a very simple patch (which wasn't obvious at all before these breakthroughs):

http://www.magiclantern.fm/forum/index.php?topic=21383.msg195229#msg195229

Still interested? (on any other camera models)