PC-3000 Forum

Hi,

I have San Disk SSD Plus (SM2246XT) that accepts loader and builds translator.

Shows that the it has certain amount of bad pages (thousands).

I set DE to ignore ECC errors.

Any sector that has no data (all zeroes) in it reads good (Green), any sector with data is ECC error.

I have tried freezing NANDs and it has no effect.

Any possible way to get around ECC errors on every sector with data?

I suspect that NANDs are too far gone?

Thank you for your time.

You can also try heating the NANDs and see if that makes a difference.

Heating the NAND chips with hot air up to +160C should help to reduce the errors.

Roman_TS wrote:Heating the NAND chips with hot air up to +160C should help to reduce the errors.

I have this intense SM2259 I loaded the loader and built the translator, but when reading it gives me many ECC errors and it is very very slow, they advised me to heat the nand chips up to 160°, but I was wondering, do the chips have to be heated constantly for the whole reading phase, or do I have to heat them and then connect it and read it?

It depends on each case. Sometimes we need to use a permanent heating of all NAND chips, sometimes we could get a positive rereading result even if we take a solder iron and will heat a single NAND chip on the board. Need to try different combinations of rereading.

Every NAND memory chip has a special thermo-sensor inside. This sensor adjusts the voltage consumption for better writing/reading process.

For examole, if the outside temperature is from +15 to + 35, it should use a default VCC for 3.3V. This voltage adjustment goes INTERNALLY inside the NAND chip. On the PCB output could be always 3.3V, but internal NAND High-Voltage-Generator adjust the voltage by itself.

All chips have a temperature-voltage table which looks like this:

-80C... need to send 2.7V
-40C... need to send 2.9V
0... need to send 3.2V
+30... need to send 3.3V
+80C... need to send 3.6V

Sometimes, these values become damaged, and the NAND chip start to "think" that the outside temperature is +80C, so it sends 3.6V instead 3.3V! And there become a shift in the values! That's why we are using the temperature to cheat the internal voltage generator and get a correct power consumption for the NAND reading.

We never know how exactly this shift will appear - it will go upper or lower. That's why we need to try both heating and freezing.