Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems.

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Posted to comp.sys.ibm.pc.hardware.storage,sci.electronics.repair
 
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Default USB flash drive - can read but can't write

I have a USB thumb drive that my computers can read but can't write.
It has a read-only switch, SPDT, but flipping it makes no difference,
nor does unsoldering it and replacing it with a jumper wire. Is there
something else that may work, such as running a special utility (The
manual refers to a "recovery disk," but the driver CD contains no such
thing) or shorting a certain reset pin?.

This device uses an OTI 6828 USB bridge chip and was distributed by
Pretec as the iDisk and also given out by Microsoft years ago (they
have nothing on it), but I can't find any information about it.

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Senior Member
 
Posts: 134
Question

Hi,

Has it only just recently stopped writing?


Quote:
Originally Posted by
I have a USB thumb drive that my computers can read but can't write.
It has a read-only switch, SPDT, but flipping it makes no difference,
nor does unsoldering it and replacing it with a jumper wire. Is there
something else that may work, such as running a special utility (The
manual refers to a "recovery disk," but the driver CD contains no such
thing) or shorting a certain reset pin?.

This device uses an OTI 6828 USB bridge chip and was distributed by
Pretec as the iDisk and also given out by Microsoft years ago (they
have nothing on it), but I can't find any information about it.
  #4   Report Post  
Posted to comp.sys.ibm.pc.hardware.storage,sci.electronics.repair
Franc Zabkar
 
Posts: n/a
Default USB flash drive - can read but can't write

On 1 Jun 2006 20:25:19 -0700, put finger to
keyboard and composed:


Franc Zabkar wrote:

On 31 May 2006 16:27:03 -0700,
put finger to
keyboard and composed:

I have a USB thumb drive that my computers can read but can't write.


This device uses an OTI 6828 USB bridge chip and was distributed by
Pretec as the iDisk and also given out by Microsoft years ago (they
have nothing on it), but I can't find any information about it.


The OTI chip has a Flash Write Protect signal on pin 18
(
http://www.costar.com.tw/pdf/OTi/Oti-6828.pdf). Have you verified
that it changes state according to the position of the read-only
switch?

Have you tried to format the drive? Is it possible that the directory
you are trying to write to has a read-only attribute???


Thank you, Frank. That's great in formation. I'll take a look at pin
18.

I had no luck formatting the drive, and nothing had the read-only
attribute enabled.


IIRC, someone with a similar problem found that there was a limit to
the number of files you could have in the drive's root directory. But
this doesn't explain your inability to format the drive ...

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
  #5   Report Post  
Posted to comp.sys.ibm.pc.hardware.storage,sci.electronics.repair
Arno Wagner
 
Posts: n/a
Default USB flash drive - can read but can't write

In comp.sys.ibm.pc.hardware.storage Franc Zabkar wrote:
On 1 Jun 2006 20:25:19 -0700, put finger to
keyboard and composed:



Franc Zabkar wrote:

On 31 May 2006 16:27:03 -0700,
put finger to
keyboard and composed:

I have a USB thumb drive that my computers can read but can't write.


This device uses an OTI 6828 USB bridge chip and was distributed by
Pretec as the iDisk and also given out by Microsoft years ago (they
have nothing on it), but I can't find any information about it.

The OTI chip has a Flash Write Protect signal on pin 18
(
http://www.costar.com.tw/pdf/OTi/Oti-6828.pdf). Have you verified
that it changes state according to the position of the read-only
switch?

Have you tried to format the drive? Is it possible that the directory
you are trying to write to has a read-only attribute???


Thank you, Frank. That's great in formation. I'll take a look at pin
18.

I had no luck formatting the drive, and nothing had the read-only
attribute enabled.


IIRC, someone with a similar problem found that there was a limit to
the number of files you could have in the drive's root directory.


That is a FAT limitation: All directories expand as needed,
except the root directory. You should still be able to rename
files and directories there and you should be able to write
in subdirectories. (The limitation is a design error IMO.)

But
this doesn't explain your inability to format the drive ...


What about this: The drive has exhausted its supply of spare
sectors and goes into a safe read-only mode now. Would be a sensible
failure mode, because the user can at least get his/her data of
the drive and there is no risk of failed writes.

Arno


  #6   Report Post  
Posted to comp.sys.ibm.pc.hardware.storage,sci.electronics.repair
Franc Zabkar
 
Posts: n/a
Default USB flash drive - can read but can't write

On 3 Jun 2006 00:49:43 GMT, Arno Wagner put finger to
keyboard and composed:

In comp.sys.ibm.pc.hardware.storage Franc Zabkar wrote:
On 1 Jun 2006 20:25:19 -0700, put finger to
keyboard and composed:



Franc Zabkar wrote:

On 31 May 2006 16:27:03 -0700,
put finger to
keyboard and composed:

I have a USB thumb drive that my computers can read but can't write.

This device uses an OTI 6828 USB bridge chip and was distributed by
Pretec as the iDisk and also given out by Microsoft years ago (they
have nothing on it), but I can't find any information about it.

The OTI chip has a Flash Write Protect signal on pin 18
(
http://www.costar.com.tw/pdf/OTi/Oti-6828.pdf). Have you verified
that it changes state according to the position of the read-only
switch?

Have you tried to format the drive? Is it possible that the directory
you are trying to write to has a read-only attribute???

Thank you, Frank. That's great in formation. I'll take a look at pin
18.

I had no luck formatting the drive, and nothing had the read-only
attribute enabled.


IIRC, someone with a similar problem found that there was a limit to
the number of files you could have in the drive's root directory.


That is a FAT limitation: All directories expand as needed,
except the root directory. You should still be able to rename
files and directories there and you should be able to write
in subdirectories. (The limitation is a design error IMO.)

But
this doesn't explain your inability to format the drive ...


What about this: The drive has exhausted its supply of spare
sectors and goes into a safe read-only mode now. Would be a sensible
failure mode, because the user can at least get his/her data of
the drive and there is no risk of failed writes.

Arno


But if the user requested a format, wouldn't that tell the drive's
smarts that the data wasn't of any consequence?

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
  #7   Report Post  
Posted to comp.sys.ibm.pc.hardware.storage,sci.electronics.repair
Tom MacIntyre
 
Posts: n/a
Default USB flash drive - can read but can't write

On Sat, 03 Jun 2006 09:10:38 +1000, Franc Zabkar
wrote:

On 1 Jun 2006 20:25:19 -0700, put finger to
keyboard and composed:


Franc Zabkar wrote:

On 31 May 2006 16:27:03 -0700,
put finger to
keyboard and composed:

I have a USB thumb drive that my computers can read but can't write.


This device uses an OTI 6828 USB bridge chip and was distributed by
Pretec as the iDisk and also given out by Microsoft years ago (they
have nothing on it), but I can't find any information about it.

The OTI chip has a Flash Write Protect signal on pin 18
(
http://www.costar.com.tw/pdf/OTi/Oti-6828.pdf). Have you verified
that it changes state according to the position of the read-only
switch?

Have you tried to format the drive? Is it possible that the directory
you are trying to write to has a read-only attribute???


Thank you, Frank. That's great in formation. I'll take a look at pin
18.

I had no luck formatting the drive, and nothing had the read-only
attribute enabled.


IIRC, someone with a similar problem found that there was a limit to
the number of files you could have in the drive's root directory. But
this doesn't explain your inability to format the drive ...


Hmmm...that's the way it is with floppies, 512 files maximum for FAT12
file system, something like that.

Tom


- Franc Zabkar


  #8   Report Post  
Posted to comp.sys.ibm.pc.hardware.storage,sci.electronics.repair
Rod Speed
 
Posts: n/a
Default USB flash drive - can read but can't write

Tom MacIntyre wrote:
On Sat, 03 Jun 2006 09:10:38 +1000, Franc Zabkar
wrote:

On 1 Jun 2006 20:25:19 -0700, put finger to
keyboard and composed:


Franc Zabkar wrote:

On 31 May 2006 16:27:03 -0700,
put finger to
keyboard and composed:

I have a USB thumb drive that my computers can read but can't
write.

This device uses an OTI 6828 USB bridge chip and was distributed
by Pretec as the iDisk and also given out by Microsoft years ago
(they have nothing on it), but I can't find any information about
it.

The OTI chip has a Flash Write Protect signal on pin 18
(
http://www.costar.com.tw/pdf/OTi/Oti-6828.pdf). Have you verified
that it changes state according to the position of the read-only
switch?

Have you tried to format the drive? Is it possible that the
directory you are trying to write to has a read-only attribute???

Thank you, Frank. That's great in formation. I'll take a look at
pin
18.

I had no luck formatting the drive, and nothing had the read-only
attribute enabled.


IIRC, someone with a similar problem found that there was a limit to
the number of files you could have in the drive's root directory. But
this doesn't explain your inability to format the drive ...


Hmmm...that's the way it is with floppies, 512 files maximum for FAT12
file system, something like that.


You can actually specify more at format time.


  #9   Report Post  
Posted to comp.sys.ibm.pc.hardware.storage,sci.electronics.repair
Jamie
 
Posts: n/a
Default USB flash drive - can read but can't write

Franc Zabkar wrote:

On 1 Jun 2006 20:25:19 -0700, put finger to
keyboard and composed:


Franc Zabkar wrote:


On 31 May 2006 16:27:03 -0700,
put finger to
keyboard and composed:


I have a USB thumb drive that my computers can read but can't write.


This device uses an OTI 6828 USB bridge chip and was distributed by
Pretec as the iDisk and also given out by Microsoft years ago (they
have nothing on it), but I can't find any information about it.

The OTI chip has a Flash Write Protect signal on pin 18
(
http://www.costar.com.tw/pdf/OTi/Oti-6828.pdf). Have you verified
that it changes state according to the position of the read-only
switch?

Have you tried to format the drive? Is it possible that the directory
you are trying to write to has a read-only attribute???


Thank you, Frank. That's great in formation. I'll take a look at pin
18.

I had no luck formatting the drive, and nothing had the read-only
attribute enabled.



IIRC, someone with a similar problem found that there was a limit to
the number of files you could have in the drive's root directory. But
this doesn't explain your inability to format the drive ...

- Franc Zabkar

on the side of the unit (at least mine) there is a lock switch that will
not allow a write or format.
this is a PNY drive stick.


--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

  #10   Report Post  
Posted to comp.sys.ibm.pc.hardware.storage,sci.electronics.repair
Michael Kennedy
 
Posts: n/a
Default USB flash drive - can read but can't write

Did you even read his post?

It has a read-only switch, SPDT, but flipping it makes no difference,
nor does unsoldering it and replacing it with a jumper wire.


Jamie t
on the side of the unit (at least mine) there is a lock switch that will
not allow a write or format.
this is a PNY drive stick.


--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5





  #11   Report Post  
Posted to comp.sys.ibm.pc.hardware.storage,sci.electronics.repair
Michael Kennedy
 
Posts: n/a
Default USB flash drive - can read but can't write

Well I will give you some credit.. The write protect switch was the first
thing I thought of also.

- Mike

"Michael Kennedy" wrote in message
news
Did you even read his post?

It has a read-only switch, SPDT, but flipping it makes no difference,
nor does unsoldering it and replacing it with a jumper wire.


Jamie t
on the side of the unit (at least mine) there is a lock switch that will
not allow a write or format.
this is a PNY drive stick.


--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5





  #12   Report Post  
Posted to comp.sys.ibm.pc.hardware.storage,sci.electronics.repair
Arno Wagner
 
Posts: n/a
Default USB flash drive - can read but can't write

In comp.sys.ibm.pc.hardware.storage Franc Zabkar wrote:
On 3 Jun 2006 00:49:43 GMT, Arno Wagner put finger to
keyboard and composed:


In comp.sys.ibm.pc.hardware.storage Franc Zabkar wrote:
On 1 Jun 2006 20:25:19 -0700, put finger to
keyboard and composed:



Franc Zabkar wrote:

On 31 May 2006 16:27:03 -0700,
put finger to
keyboard and composed:

I have a USB thumb drive that my computers can read but can't write.

This device uses an OTI 6828 USB bridge chip and was distributed by
Pretec as the iDisk and also given out by Microsoft years ago (they
have nothing on it), but I can't find any information about it.

The OTI chip has a Flash Write Protect signal on pin 18
(
http://www.costar.com.tw/pdf/OTi/Oti-6828.pdf). Have you verified
that it changes state according to the position of the read-only
switch?

Have you tried to format the drive? Is it possible that the directory
you are trying to write to has a read-only attribute???

Thank you, Frank. That's great in formation. I'll take a look at pin
18.

I had no luck formatting the drive, and nothing had the read-only
attribute enabled.


IIRC, someone with a similar problem found that there was a limit to
the number of files you could have in the drive's root directory.


That is a FAT limitation: All directories expand as needed,
except the root directory. You should still be able to rename
files and directories there and you should be able to write
in subdirectories. (The limitation is a design error IMO.)

But
this doesn't explain your inability to format the drive ...


What about this: The drive has exhausted its supply of spare
sectors and goes into a safe read-only mode now. Would be a sensible
failure mode, because the user can at least get his/her data of
the drive and there is no risk of failed writes.

Arno


But if the user requested a format, wouldn't that tell the drive's
smarts that the data wasn't of any consequence?


A "format" ooperation on Windows is not a format. MS confused the
terms. For hard-sectored devices like HDDs or memory sticks a "format"
on Windows is actually filesystem creation and on most other OSes it
is called that. Filesystem creation looks to the drive just like
ordinary writes, nothing special about them. So if the device refuses
writes, it consequentially also refuses "formats".

Arno

  #13   Report Post  
Posted to comp.sys.ibm.pc.hardware.storage,sci.electronics.repair
JANA
 
Posts: n/a
Default USB flash drive - can read but can't write

With these drives, when they fail, I replace them. I am on my third one in
about 6 months. I think static electricity in my pockets or something else
is damaging them.

--

JANA
_____


wrote in message
ups.com...

Franc Zabkar wrote:

On 31 May 2006 16:27:03 -0700, put finger to
keyboard and composed:

I have a USB thumb drive that my computers can read but can't write.


This device uses an OTI 6828 USB bridge chip and was distributed by
Pretec as the iDisk and also given out by Microsoft years ago (they
have nothing on it), but I can't find any information about it.


The OTI chip has a Flash Write Protect signal on pin 18
(
http://www.costar.com.tw/pdf/OTi/Oti-6828.pdf). Have you verified
that it changes state according to the position of the read-only
switch?

Have you tried to format the drive? Is it possible that the directory
you are trying to write to has a read-only attribute???


Thank you, Frank. That's great in formation. I'll take a look at pin
18.

I had no luck formatting the drive, and nothing had the read-only
attribute enabled.


  #14   Report Post  
Posted to comp.sys.ibm.pc.hardware.storage,sci.electronics.repair
Michael Kennedy
 
Posts: n/a
Default USB flash drive - can read but can't write

Can you re-partition it?
Fdisk or for xp disk management..

Just a thought.. probably won't work either, but I'd give it a try.

- Mike

"Arno Wagner" wrote in message
...
In comp.sys.ibm.pc.hardware.storage Franc Zabkar
wrote:
On 3 Jun 2006 00:49:43 GMT, Arno Wagner put finger to
keyboard and composed:


In comp.sys.ibm.pc.hardware.storage Franc Zabkar
wrote:
On 1 Jun 2006 20:25:19 -0700, put finger to
keyboard and composed:


Franc Zabkar wrote:

On 31 May 2006 16:27:03 -0700,
put finger to
keyboard and composed:

I have a USB thumb drive that my computers can read but can't write.

This device uses an OTI 6828 USB bridge chip and was distributed by
Pretec as the iDisk and also given out by Microsoft years ago (they
have nothing on it), but I can't find any information about it.

The OTI chip has a Flash Write Protect signal on pin 18
(
http://www.costar.com.tw/pdf/OTi/Oti-6828.pdf). Have you verified
that it changes state according to the position of the read-only
switch?

Have you tried to format the drive? Is it possible that the directory
you are trying to write to has a read-only attribute???

Thank you, Frank. That's great in formation. I'll take a look at pin
18.

I had no luck formatting the drive, and nothing had the read-only
attribute enabled.

IIRC, someone with a similar problem found that there was a limit to
the number of files you could have in the drive's root directory.

That is a FAT limitation: All directories expand as needed,
except the root directory. You should still be able to rename
files and directories there and you should be able to write
in subdirectories. (The limitation is a design error IMO.)

But
this doesn't explain your inability to format the drive ...

What about this: The drive has exhausted its supply of spare
sectors and goes into a safe read-only mode now. Would be a sensible
failure mode, because the user can at least get his/her data of
the drive and there is no risk of failed writes.

Arno


But if the user requested a format, wouldn't that tell the drive's
smarts that the data wasn't of any consequence?


A "format" ooperation on Windows is not a format. MS confused the
terms. For hard-sectored devices like HDDs or memory sticks a "format"
on Windows is actually filesystem creation and on most other OSes it
is called that. Filesystem creation looks to the drive just like
ordinary writes, nothing special about them. So if the device refuses
writes, it consequentially also refuses "formats".

Arno



  #15   Report Post  
Posted to comp.sys.ibm.pc.hardware.storage,sci.electronics.repair
Michael Kennedy
 
Posts: n/a
Default USB flash drive - can read but can't write

yeah it happens to the best of us


"Jamie" t wrote in message
...
Michael Kennedy wrote:

Did you even read his post?


It has a read-only switch, SPDT, but flipping it makes no difference,
nor does unsoldering it and replacing it with a jumper wire.



Jamie t
on the side of the unit (at least mine) there is a lock switch that will
not allow a write or format.
this is a PNY drive stick.


--

sorry, i must of missed that.
btw, i think you have to have it pulled from the USB , set the switch
and then plug it back in.




--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5





  #16   Report Post  
Posted to comp.sys.ibm.pc.hardware.storage,sci.electronics.repair
Jamie
 
Posts: n/a
Default USB flash drive - can read but can't write

Michael Kennedy wrote:

Did you even read his post?


It has a read-only switch, SPDT, but flipping it makes no difference,
nor does unsoldering it and replacing it with a jumper wire.



Jamie t
on the side of the unit (at least mine) there is a lock switch that will
not allow a write or format.
this is a PNY drive stick.


--

sorry, i must of missed that.
btw, i think you have to have it pulled from the USB , set the switch
and then plug it back in.




--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

  #17   Report Post  
Posted to comp.sys.ibm.pc.hardware.storage,sci.electronics.repair
Arno Wagner
 
Posts: n/a
Default USB flash drive - can read but can't write

In comp.sys.ibm.pc.hardware.storage Michael Kennedy wrote:
Can you re-partition it?
Fdisk or for xp disk management..


Just a thought.. probably won't work either, but I'd give it a try.


That is also not a special operation from the point of view of
the drive.

Arno

  #18   Report Post  
Posted to comp.sys.ibm.pc.hardware.storage,sci.electronics.repair
Arno Wagner
 
Posts: n/a
Default USB flash drive - can read but can't write

In comp.sys.ibm.pc.hardware.storage JANA wrote:
With these drives, when they fail, I replace them. I am on my third one in
about 6 months. I think static electricity in my pockets or something else
is damaging them.


Maybe you just write a lot or a lot of small files?
USB is very well protected against static electicity....

Arno
  #19   Report Post  
Posted to comp.sys.ibm.pc.hardware.storage,sci.electronics.repair
Franc Zabkar
 
Posts: n/a
Default USB flash drive - can read but can't write

On Sat, 3 Jun 2006 20:39:48 -0400, "JANA" put
finger to keyboard and composed:

With these drives, when they fail, I replace them. I am on my third one in
about 6 months. I think static electricity in my pockets or something else
is damaging them.


AFAIK, a common problem with these is that they develop dry solder
joints at the connector pins, probably due to mechanical stress.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
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