Sandisk Cruzer Contour 4GB voltages or restistors

[outbreak198x]

Hello,

i got this stick to recover, and of course it has a fine encrpted Controller.

I'm a little bit worried about this one, because it does nothing when connecting to USB - but the Fuse is OK.

i don't know a lot of voltages and resistors in USB Sticks - normally i just take it off and do a NAND dump rebuild controller.

on the fuse i have 2,34V - and that's whats not normal for me - shouldn't that be 5V? the only 5V i have i marked in picture.

anyone have some ideas?

backside too

[Lardman]

5v is supplied but the controller / nand doesn't use 5v. Check the current being drawn it will give you an indication of what's going on and at what stage, have you checked the vcc on the tsop - anything there?

Given the physical design I wouldn't be surprised if the controller hadn't lifted a bit and needed a reflow.

[outbreak198x]

my PC3000 tells me 0,00A at 5V
and i have around 0,9V on TSOP

[Lardman]

my PC3000 tells me 0,00A at 5V

Wrong tool for the job, grab a cheap usb meter and watch what happens when you plug the stick in. Does the controller get warm any of the caps.

[fzabkar]

Measure the voltages on the capacitors. I expect that you will find Vcore and Vio for the flash controller, plus the Vcc for the NAND flash.

The "E" component looks like an inductor. I would have expected that this would be the Vcore supply for the controller. :-? In fact 0.9V looks like a Vcore supply, so maybe 2.34V is the Vio supply?

[outbreak198x]

my PC3000 tells me 0,00A at 5V

Wrong tool for the job, grab a cheap usb meter and watch what happens when you plug the stick in. Does the controller get warm any of the caps.

Maybe not the correct tool, but PC3000 Portable III at least should show some mA, because it does at all other sticks

but maybe a cheap USB Meter will do the thing too

[Lardman]

PC3000 Portable III at least should show some mA

I assumed you were referring to PC3000 flash rather than portable. You plug unknown usb drives into it? really not sure I want to do that.

[fzabkar]

Measure the resistance of the resistor. I expect it will be around 1 or 2 ohms.

Then measure the voltage across this resistor in normal operation. This will tell you how much current is being drawn by the flash drive (V = I x R).

Attachments

resistor_inductor.jpg (61.76 KiB) Viewed 13571 times

[outbreak198x]

Measure the resistance of the resistor. I expect it will be around 1 or 2 ohms.

Then measure the voltage across this resistor in normal operation. This will tell you how much current is being drawn by the flash drive (V = I x R).

that was my first measurement, and it's around 680Ohms... and i think it should be a 0 Ohm resistor?

[outbreak198x]

PC3000 Portable III at least should show some mA

I assumed you were referring to PC3000 flash rather than portable. You plug unknown usb drives into it? really not sure I want to do that.

why not? portable II has extra USB Source for it?

[fzabkar]

Measure the resistance of the resistor. I expect it will be around 1 or 2 ohms.

Then measure the voltage across this resistor in normal operation. This will tell you how much current is being drawn by the flash drive (V = I x R).

that was my first measurement, and it's around 680Ohms... and i think it should be a 0 Ohm resistor?

Maybe I'm wrong. Usually the resistor in this position is physically larger. I wouldn't replace it without more examination. 680 ohms is a standard value.

Did I correctly identify the inductor, or was that an error, too? Is it a fuse or polyswitch?

Edit: I think it is a polyswitch.

https://www.littelfuse.com/products/polyswitch-resettable-pptcs/surface-mount.aspx
https://www.littelfuse.com/products/polyswitch-resettable-pptcs/surface-mount/0805l.aspx

Last edited by fzabkar on March 14th, 2022, 19:41, edited 3 times in total.

[Blizzard]

Measure the resistance of the resistor. I expect it will be around 1 or 2 ohms.

Then measure the voltage across this resistor in normal operation. This will tell you how much current is being drawn by the flash drive (V = I x R).

that was my first measurement, and it's around 680Ohms... and i think it should be a 0 Ohm resistor?

Maybe I'm wrong. Usually the resistor in this position is physically larger. I wouldn't replace it without more examination. 680 ohms is a standard value.

Did I correctly identify the inductor, or was that an error, too? Is it a fuse or polyswitch?

I'm pretty sure that's a LittelFuse and it usually measures 5v at the fuse on that device.

[fzabkar]

I'm pretty sure that's a LittelFuse and it usually measures 5v at the fuse on that device.

Thanks. I guess I'll call that a brain fart.

As you say, I would confirm that +5V exists on the input side. Then I would measure the resistance between the output (load) side and ground. It could be that there is a problem in the flash controller or NAND. When the polyswitch cools down, it should measure close to 0 ohms between input and output.

[Lardman]

why not? portable II has extra USB Source for it?

Replacement costs - a cooked usb meter is considerably cheaper and easier to replace than pc3k.

[outbreak198x]

Measure the resistance of the resistor. I expect it will be around 1 or 2 ohms.

Then measure the voltage across this resistor in normal operation. This will tell you how much current is being drawn by the flash drive (V = I x R).

that was my first measurement, and it's around 680Ohms... and i think it should be a 0 Ohm resistor?

Maybe I'm wrong. Usually the resistor in this position is physically larger. I wouldn't replace it without more examination. 680 ohms is a standard value.

Did I correctly identify the inductor, or was that an error, too? Is it a fuse or polyswitch?

Edit: I think it is a polyswitch.

https://www.littelfuse.com/products/polyswitch-resettable-pptcs/surface-mount.aspx
https://www.littelfuse.com/products/polyswitch-resettable-pptcs/surface-mount/0805l.aspx

That's why i wrote in first article, but the Fuse is OK - in my thought it is a Fuse

[outbreak198x]

why not? portable II has extra USB Source for it?

Replacement costs - a cooked usb meter is considerably cheaper and easier to replace than pc3k.

i think that could be true

[outbreak198x]

I'm pretty sure that's a LittelFuse and it usually measures 5v at the fuse on that device.

Thanks. I guess I'll call that a brain fart.

As you say, I would confirm that +5V exists on the input side. Then I would measure the resistance between the output (load) side and ground. It could be that there is a problem in the flash controller or NAND. When the polyswitch cools down, it should measure close to 0 ohms between input and output.

The NAND is "OK", because i already read it out with TSOP48 Reader, but... it's useless in that case.

it also measures 0 Ohm, when i just turn on the device. so in off 680Ohm - on 0 Ohm.

[fzabkar]

That's why i wrote in first article, but the Fuse is OK :D - in my thought it is a Fuse :D

Sorry, I'm having a bad run lately. Anyway, if it was a fuse rather than a polyswitch, it would either be open or closed. That is, you would be measuring 5V or 0V ... I think.

[outbreak198x]

Resistor Changed, everything fine now