baudrate on serial (RS232) port (RTG pins) on MK809III

[flx]

Hi,

I've killed my MK809III (new WIFI) by flashing an UG007b image. Now there is no more HDMI output and the device isn't recognized on USB anymore (whether I boot with while pushing the button or not).

I've soldered an DB9 connector to the RTG pins and connected it to the RS232 port of my PC. I only get garbage on the Terminal (putty), no whether which speed from 300-115200 baud I've tried. Other settings are 8,n,1 without flowcontrol.

Does anyone know which speed is the correct one to see on the serial console what happens during boot? Maybe it uses a speed >115200 bps which my PC hardware doesn't support?

Thanks,
flx

[flx]

Successfully unbricked my MK809III

I learned that the voltage level of the RTG pins (RS232) are NOT normal RS232 Levels, but they are TTL level. This is the reason why only garbage is displayed with any bitrate. Using a USB/serial converter didn't improve the situation. I need a converter, which I've ordered in China but will arrive in about one month.

Since waiting that long seemed too boring to me, I gave it a try to shorten the relevant PINs of my NAND flash chip while powering on the MK809III. These are pins 7&8. Then the device can be flashed in mask rom mode.

I've managed to unbrick the device!

This might be interesting for other people who bricked their MK809III. I guess this is the same procedure for MK802IV or similar devices. One should carefully read the NAND pin assignment before trying this!

Cheers,
flx

[tattman65]

I learned that the voltage level of the RTG pins (RS232) are NOT normal RS232 Levels, but they are TTL level. This is the reason why only garbage is displayed with any bitrate. Using a USB/serial converter didn't improve the situation. I need a converter, which I've ordered in China but will arrive in about one month.

Since waiting that long seemed too boring to me, I gave it a try to shorten the relevant PINs of my NAND flash chip while powering on the MK809III. These are pins 7&8. Then the device can be flashed in mask rom mode.

I've managed to unbrick the device!

This might be interesting for other people who bricked their MK809III. I guess this is the same procedure for MK802IV or similar devices. One should carefully read the NAND pin assignment before trying this!

Cheers,
flx

good job man ! and thanks for posting the info for other members . i will move this post later to the correct thread so others may find it more easily

[darekmarta1975]

not come up with anything new, it has long been known

[flx]

not come up with anything new, it has long been known

Well, in this case it would have been more helpful if you had posted a link to this info (shortening pin 7&8 on H27UCG8T2BTR-BC chip which is in my MK809III) earlier, instead of complaining afterwards about posting a "long known info".

It took me long time to find this info and I just wanted to save other peoples time, who might have the same problem.

[darekmarta1975]

blocking the memory are dependent on the memory model.
They are such possibilities 5 and 6, 7 and 8, 8 and 9

[write-tome]

I learned that the voltage level of the RTG pins (RS232) are NOT normal RS232 Levels, but they are TTL level. This is the reason why only garbage is displayed with any bitrate. Using a USB/serial converter didn't improve the situation. I need a converter, which I've ordered in China but will arrive in about one month.

Since waiting that long seemed too boring to me, I gave it a try to shorten the relevant PINs of my NAND flash chip while powering on the MK809III. These are pins 7&8. Then the device can be flashed in mask rom mode.

I've managed to unbrick the device!

This might be interesting for other people who bricked their MK809III. I guess this is the same procedure for MK802IV or similar devices. One should carefully read the NAND pin assignment before trying this!

Cheers,
flx

Hi I have this MK809III ... bricked !!! ( see attached photo )
please may You indentify pins 7&8 in my photo ?
I really appreciate !

Thanks in advance

[flx]

Hi I have this MK809III ... bricked !!! ( see attached photo )
please may You indentify pins 7&8 in my photo ?
I really appreciate !

Thanks in advance

pin 1 is marked with a small circle. Then count within the row until you reach your pins. First shorten the pins, and then connecdt the usb calbe to your pc.

[write-tome]

pin 1 is marked with a small circle. Then count within the row until you reach your pins. First shorten the pins, and then connecdt the usb calbe to your pc.

I'm happy to inform that mu MK809III is alive again !

I realize that in my box the nand flash is: H27UBG8T2BTR and I read that You have to short,
for this component, pins 8 e 9 (First shorten the pins, and then connect the usb cable to your pc)
see the very good tread:

http://www.freaktab.com/showthread.php?1943-Unbrick-or-fix-NAND-on-the-MK808

All went OK !
See attachement where pins 8 and 9 are marked

Thanks to all of You