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SD 2GB BADS

Posted: September 30th, 2008, 9:30
by sempre
HI to all!

What problem?
look photo!

Re: SD 2GB BADS

Posted: September 30th, 2008, 10:34
by pcimage
You have a controller problem by the look of it.

Nand chip needs to be removed and the data decoded.

Either myself or Bosse (mr_spokk) can almost certainly do this for you.

Sean

Re: SD 2GB BADS

Posted: September 30th, 2008, 13:15
by dick
Yes maybe a controller or firmware problem.

I would still reflow the memory chip/chips themselves before removing them as just one dry joint can cause exactly the same symptoms.

Re: SD 2GB BADS

Posted: September 30th, 2008, 14:07
by Vulcan
The original photo shows just sector 0 is unreadable. Depending on how many sectors are unreadable in total, then as well as possible dry joints & controller faults mentioned already, I've also seen this where (after reading the NAND chip directly) I found exactly one _physical block_ on the flash chip (often 128kB) was erased i.e. every byte (including spares) in that block = 0xFF. IMHO, that could be a flash controller firmware bug, where it had erased the block and then not programmed it (or, perhaps, a power-failure occurred between those 2 stages) - so those are other possibilities. Difficult to say with the limited data provided...

Re: SD 2GB BADS

Posted: September 30th, 2008, 16:16
by Amarbir[CDR-Labs]
Hi ,
Please REsolder The Nand Flash And the MCU ,check For The Voltage Regulators and then make sure that crystal is actually working by a frequency meter in a scope or multimeter

Re: SD 2GB BADS

Posted: October 1st, 2008, 3:06
by dick
Sorry but I think it appears I misunderstood your post and that you have a SD memory card................your options are VERY limited as the advice I offered before will not be of any use with this device. :cry:

Re: SD 2GB BADS

Posted: October 1st, 2008, 17:34
by sempre
Thanks all helps!

All sectors bads!

Re: SD 2GB BADS

Posted: October 1st, 2008, 18:41
by Amarbir[CDR-Labs]
dick wrote:Sorry but I think it appears I misunderstood your post and that you have a SD memory card................your options are VERY limited as the advice I offered before will not be of any use with this device. :cry:


Sorry i also Did ,

Well Boss You Have No option Other Then To Buy a Nand Flash Reader And Then Using Dedicated Software Reconstructing the read nand flash ,and if the nand flash cannot be read then nothing can be done