repair advice for bad NAND blocks

[mspencer]

I have a 14 month old SL-C700 with hardware problems.  Tonight I\'m going over to my Japanese teacher\'s house, and together we\'re going to call Sharp Japan tech support and try to get help.  She warned me that Japanese are typically very regimented, so I may have problems getting detailed technical information from line-level support staff.  I\'d like to pose my question to the group here also:

First:  I\'ve flashed replacement OS images and erased and reloaded dozens of times.  This is not a simple newbie issue.  :)

I know I have bad \"NAND\" flash in my C700.  I may or may not have other hardware problems.  I\'m trying to determine whether it would be a waste of time to hire an experienced electronics technician to replace the flash chips in my C700, or if I should instead just send the C700 to Japan.

I\'ll first describe what my C700 is doing now, and then will describe the symptoms I saw before the C700 failed completely.

Currently the C700 can get into the D+M menu, but only intermittently.  (I\'ve been in this menu dozens of times, so this is not a user training issue.)  Usually if I press and hold D+M and toggle the battery lock, the flashing email light stops its flashing temporarily, and then starts again.  I\'ve been unable to get into the D+M menu for the past two days -- except for today, when I tried and it worked.

I have a SYSTC700.DBK file on a write-protected SD card.  When I use the D+M menu\'s \"NAND Flash Restore\" option, the restore process runs for a few seconds (maybe 10 to 15 lines worth of green bar) and then says:

Code: [Select]

NAND Restore from SD

file:SYSTC700.DBK

Execute restore?

Delete all flash data?

Restore...failed

format error

If I go into EXTRA MENU, then Zaurus Test, then NAND Flash (Full), this test runs a destructive write-read test of my flash and tells me I have 2001 bad flash blocks:

Code: [Select]

NAND Flash (Full)



checking ecc... OK.

writing all 1...

adr = 4000000

Bad Block Num = 2001

verifying 1...

adr = 4000000

Bad Block Num = 2001

writing all 2...

adr = 4000000

Bad Block Num = 2001

verifying 2...

adr = 4000000

Bad Block Num = 2001

checking number...OK.

success.

Also, interestingly, as it tests flash it counts forward in 2^20 increments, starting from 100000 and counting upward toward 4000000.  Between ranges c00000 and 2900000 it counts very quickly, as if each block is failing completely and the test is being aborted on each block in that range.

So that\'s where I\'m at right now.  The problem seemed to start Tuesday before last (March 30).  Here\'s what I observed back then:  (quoted from my April 2 post at externe.net\'s older C700 forum)

I think I have a specific kind of hardware failure, but I\'m not sure what\'s wrong. I probably can\'t fix it on my own, but I\'d like to understand the problem. This isn\'t really flashing-related: I\'ve been running the same Sukoshi rom for several weeks. I\'m noticing three kinds of failures:

first failure type: the machine will occasionally lock up, hard. The clock stops, the battery meter stops playing its \'plugged into power\' animation, and no key presses, card inserts and removals, or other inputs will make it react. I can toggle the battery lock switch and it\'ll restart.

second failure type: sometimes after toggling the battery lock switch, the email light will flash, as if to say it can\'t boot. Sometimes if I just toggle the switch again it\'ll boot normally; sometimes I have to toggle the switch several times; or sometimes I have to take the battery completely out and leave it without power for several minutes before trying again. It\'s running again right now though.

third failure type: occasionally I\'ll have programs refuse to start, or crash in the middle of running. Qtopia will restart sometimes. I\'ve had some odd filesystem corruption also, and the system has been unable to find important executables (like cardctl).

After I started seeing that third type of failure, I backed everything up and flashed the latest Cacko QT ROM. This ROM has one important difference: when Qtopia starts I get a \"wait 5, 4, 3, 2, 1\" screen that gives me a chance to bail out of Qtopia and get a console-only command prompt. When I do that after Qtopia crashes and restarts, I see the following in my system log (dmesg command):

sharp_sl_nand_read_ecc: Failed ECC read, page 0x00003a5b
sharp_sl_nand_read_ecc: Failed ECC read, page 0x00003a5b
mtd->read(0x44 bytes from 0x4b7a4) returned ECC error
Node CRC 1c614139 != calculated CRC 51a10890 for node at 0004b7a4

These four lines are repeated dozens of times, filling the entire buffer printed by dmesg.

While in console-only mode, sometimes my shell will crash and I\'ll be back at a login screen again. After several crashes I would be able to log in, but when I tried to execute a single command I\'d be back at a login prompt again. After several repeats of *that*, the login manager is unable to start correctly and starts spawning repeatedly, causing init to shut it down for 5 minutes.

For a while I was able to run Qtopia, and I ran the \'badblocks\' program to look for bad Flash blocks.  Strangely enough, I didn\'t find any:

OK, now this is weird:

Right now I\'m sitting here running:
badblocks -p 1000 /dev/mtdblock0 &
badblocks -p 1000 /dev/mtdblock1 &
badblocks -p 1000 /dev/mtdblock2 &
badblocks -p 1000 /dev/mtdblock3 &

and it\'s just sitting there making the whole system unusably slow, but thrashing NAND like crazy. It\'s not finding *any* bad blocks. (Hopefully I\'ll get a chance to see the error messages when it finally finds problems.)

But it\'s been running this for over 30 minutes now, and hasn\'t found any bad blocks.

So might this mean I have some kind of intermittent problem that makes the whole flash memory subsystem flaky? Maybe it\'ll sit here and run fine for a while, and then suddenly be unable to read *anything*. I\'m not sure.

The C700 is an amazing device -- I never realized how much I used it every day until I was without it.  I\'d love to get it back up and running soon, and hopefully without sending it back to Japan.

Thanks again for your help, guys!  I\'ll post back here if I find out anything new from my call to Sharp Japan.

--Michael Spencer

[mspencer]

I finished my phone call with Sharp Japan tech support.  I learned quite a few things:

*  They really aren\'t expecting SL-Cxxx devices to leave Japan.  \"Where did your student get the device?\"  and \"Can\'t they call Sharp USA?\"  I think we knew that though.
*  When they repair and return devices, they must mail them to an address in Japan.  Apparently it\'s a common, everyday thing there to send replaced hardware cash-on-delivery, and have the delivery person collect the repair fee before releasing the device.  They will accept a package from the USA, but won\'t mail anything back to the USA.  They also won\'t use an alternative shipping carrier, or accept payment over the phone.
*  The best place to send the device to is:

Code: [Select]

Tokyo Technical Center

Sharp Engineering Co.

2-13-17

Higashi-Tabata

Kitaku, Tokyo, Japan

phone:  03-5692-7765
*  The maximum repair fee for an SL-C700 is allegedly 10k yen, which is somewhere around $100 US.  I found that to be surprisingly cheap.
*  The D+M menu we know and love is considered off-limits.  The support person wanted to know where I found out about that menu.
*  Apparently their standard troubleshooting script for flashing email + power lights is:  remove the battery and leave it for at least 3 hours.  Plug it back in.  If it\'s still flashing, send the unit in for repair.
*  Take-sensei was not impressed by their unwillingness to let us talk to an engineer, or even return international phone calls, send faxes, or even emails.  So Sharp Japan gets negative points for customer service.
*  Then again, a customer service rep answered with no delay.  Positive customer service points for having no service queue.  

It\'s scary that it has to come to this, but -- apparently there\'s more technical talent available here in this forum than in Sharp Japan\'s customer service department.  What do you guys think about the device behavior I described in my previous post?  Does it sound like I might be able to just replace the flash chips in the device and fix the problem myself?  Or should I not risk it, and just spend 2 weeks and $150 and have the device repaired by Sharp Japan?

--Michael Spencer

[gene]

I wouldn\'t risk it. Having them replaced here may or may not solve the problem and will probably run you the same cash. Good things come to those who wait. Plus you will appreciate your device that much more in two weeks.

[Pentad]

Hi Michael,

Here is my info for working with Sharp Japan.  I was having some issues with my 760 and I wanted to find out my support options with Sharp Japan since Sharp USA has no idea what is going on.  I faxed over a letter to Sharp Corp asking for an email for Sharp Tech Support Japan which included my email address.  This guy emailed me:

takeda.shuhhei@sharp.co.jp

With this email:



Takeda-S wrote:


Dear Sir,

Thank you very much for using a Sharp Zaurus.



Please forward your query to the following e-mail address:  .

    customer@cmn.hirano.sharp.co.jp



Best regards,

Takeda, Sharp-Japan

So I forwarded my request to the email Takeda sent me.  I didn\'t hear anything for like 36 hours so I sent another to Takeda about not getting any help.  I just figured it might be an English language problem.

Takeda responded right away with these to CC telling me Sharp will get back with me right away.


nishimura.masami@sharp.co.jp,  icdc@sesl.global.sharp.co.jp


THen I got an email from this person:

kohzai.wataru@sharp.co.jp

with these emails CC\'d:

shintaku.toshinobu@sharp.co.jp
takeda.shuhhei@sharp.co.jp

Now I would email all these folks with one email detailing your problem and asking for help.  I think its amazing that Sharp Japan won\'t give us help.  I mean I got my 760 from Japan to my house in 3 days for $35 so I know its not a shipping cost issue.  I just think its poor of Sharp to not give us support when its really not that big of a deal.

</rant>

Anyway, Michael, I really feel for you and I wanted to give you all the info/email address\'s that I had.  I hope it helps and good luck!!!

Mark

[mspencer]

I think I can understand why they might choose to only use that shipping method:  if they take payment over the phone, whatever payment method the customer uses probably has chargeback rights for card-not-present sales.  They\'re probably doing these repairs very close to at-cost, so they want to eliminate the risk of people charging back repair costs, claiming they didn\'t authorize the charge.  If a delivery person is at their door, swiping a card through a machine in-person, the person can\'t claim they didn\'t authorize the sale.  They also can\'t claim they never received the device.

It makes sense from a risk perspective, why they would work that way.

Doesn\'t make it any more convenient for me, though.  

(I work for a major credit card processor, so these issues make sense to me at least  )

Thanks again for your help, guys.

--Michael Spencer

[Pentad]

Michael,

Do we (the community) have anybody in Japan that could handle the repair for you?  Example:  Send it to him, he sends/gives it to Sharp, sends it back to you after its repaired.  Of course you pay for all the shipping, etc...  or You send to Sharp, Sharp sends to Fellow Zaurus User in Japan, he sends it back to you.  Again, you pay for any shipping costs.

I know there Z fans in Japan but I didn\'t know if any of them are also on this forum.  I think a few of them wouldn\'t mind helping their fellow Z users in the US.

Just a thought....
Mark

[mspencer]

Well, Take-sensei said she\'s going home to visit some family mid next month, so once I know when she\'ll be there I could send the Zaurus and have Sharp send it C.O.D. to her family\'s house.  She also has an uncle in...did she say Chiba?...but she said her Uncle would probably pay for the repair and not allow anyone to pay him back, touching off some kind of gift-giving one-ups-manship as she tried to repay the favor.  Japanese culture seems inscrutable that way, although still fascinating.    (and listening to that phone conversation helped me see:  even after four semesters of Japanese language study, normal adult usage of the language is complex both linguistically and socially, and I really only know enough Japanese to pass quizzes and tests -- not real actual communication yet.)

I\'m trying to get my old Agenda VR3 PDA working again, but it\'s not curbing the C700-withdrawl pains so well.  Talk about bad timing, too -- I just received my MuVo2 4 GB last Monday, and have no Zaurus to use the cannibalized microdrive with.  (Once I get my C700 back, I\'ll try to pay the community back by making digital camcorder video of the drive-extraction and Zaurus-preparation process.   )

Thanks again guys!

--Michael Spencer

[Stubear]

Very little is done on credit card here in Japan, the delivery people never take credit cards - it\'s cash or nothing in my experience. People here often send cash in specially marked envelopes or use postal savings deposits or pay in a convenience store.

Plastic is just not that popular - maybe different in Tokyo but in Osaka 24 ATMs are a new thing!

I\'m available as a transit point if need be - as long as the number of returns doesn\'t make it a full time job

[mspencer]

I went ahead and sent my device to Dynamism.  According to them, Sharp Japan charged the equivalent of $360 USD for the repair.  It\'s being shipped back to me for $400 (including shipping).

Ouch.  It\'ll be good to have the C700 back, though.

--Michael Spencer

[vishnja]

Ouch! That is much more than we expected, right? Didn\'t Sharp say \"not more than 100$\" before?
I hope your Z will be back soon so you can get an opportunity to play around withe the MuVo drive :-)

I think, we all learned a lot from your experience,
Kathrin

[kitsnews]

mspencer,

I got the same as yours. I also find bad block in \"Zaurus Test\"-]\"Nand Flash (Full)\". I would like to know is that mean my Z is unrecoverable anymore. I can\'t restore aymore flash now.

Could you give me some advice?

Thanks in advance

[padishah_emperor]

I went ahead and sent my device to Dynamism.  According to them, Sharp Japan charged the equivalent of $360 USD for the repair.  It\'s being shipped back to me for $400 (including shipping).

Ouch.  It\'ll be good to have the C700 back, though.

--Michael Spencer

aw! You do know that conics do reconditioned C700s for $399?

I think I\'m going to start putting money aside each month just incase I ever have an unexpected Z emergency.

[mspencer]

mspencer,

I got the same as yours. I also find bad block in \"Zaurus Test\"-]\"Nand Flash (Full)\". I would like to know is that mean my Z is unrecoverable anymore. I can\'t restore aymore flash now.

Could you give me some advice?

Thanks in advance

You might consider trying to erase flash, and then run the bad blocks test again.  Other than that, yeah, I\'d say you should send it in.  I\'m no expert on the subject though.

--Michael Spencer

[kitsnews]

You might consider trying to erase flash, and then run the bad blocks test again.  Other than that, yeah, I\'d say you should send it in.  I\'m no expert on the subject though.

--Michael Spencer

Thanks for your advise. I think no one want to be the expert of this subject!!!!

By the way, could you tell me how to erase the flash? I can\'t find it in DM mode or even extra of DM.

Thanks in advance.

[DrWowe]

If you\'re careful, you could try erasing the flash using Linux.  It could be a little complicated unless you\'re a Linux guru, but the basic idea would be to boot from the special ROM Linux (or alternately setup a ramdisk setup with the essential utilities), unmount all the flash filesystems, and run the flash_erase utility, which you can get in the mtdtools package I uploaded here recently.  Then go back and restore the flash.

p.s.  I make no guarentees this is really a good idea.