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Hello, I am trying to sort out an issue with a N90FHDRK. First, thank you for all the time and patience everyone involved seems to contribute. Hopefully one of you clever gents can point me in the right direction.

I suspect there may be a problem with the internal memory.  I am able to flash using batchtool succsesfully. I've used a few different firmwares offered for this RK tablet (including the 2 mentioned in this thread). I've used the nand flash, tried erase IDB, tried reformatting partitions with busybox and the problem always returns.

Issue: Once firmware is flashed the unit boots as it should, I setup WiFi with no issues, do google credentials, update the aps. Everything seems good and then... crash, hang, or unresponsive. Then it won't boot again, it will either hang on the loading screen or boot to recovery, or nothing and will only go into flash mode. This happens with all firmwares I've tried except the stock 4.1.1 or 4.2.2 firmware.

I have tried to sort this out on my own for days now. I realize I can just resign to using a stock firmware but I can't give up without putting this out to the forum. OK, I'll leave it at that.. I will appreciate any suggestions.

Thank you for the reply Oma.

I have tried to verify defective nand with the stock firmware. However the issue will not present itself with stock firmware. Everything functions as it should.. no issue with stock 4.1.1 or 4.2.2. This is what had me scratching my head and seeking your advice.

Perhaps some sort of reminant from stock fw remains on the nand following a flash. I could be way off .. but maybe a thorough wipe/scrub and format of the nand might help. Is there a procedure to do this? or any other suggestions?

I tried the KK build v2.2 (with the N90FHDRK kernel). Flashed ok, booted ok, WiFi ok, updates ok. Everything looked good. I was even able to reboot a couple times with relatively quick load times which I couldn't do with any other Oma firmware. Then it turned off or crashed I guess.. randomly. Following that it would boot into the loading screen with the colored "X" and stay there, I left it for 20 minutes before I turned it off. I tried to boot it again into recovery with success, then a factory reset and got the same result, it stayed on the boot screen again.

The v2.2 KK test showed improvement but not a success. Thank you for your suggestion. I am willing to try anything else within my ability if you have any further ideas to help me flash updated firmware. If not I will just stick with the old tired stock firmware.