MK 808 dead after 1 month succesfull operation

bayliner195
Posts: 6
Joined: Mon Oct 15, 2012 8:02 am

MK 808 dead after 1 month succesfull operation

Postby bayliner195 » Thu Nov 08, 2012 3:50 am

yesterday when I try turning on my MK808 no more Google TV screen on tv, an no more blue lighting LED.Seems absolutly dead.
Any idea?
The power supply is ok, originally I had 5V/2A unit.I checked, it is charging other devices.

moritzerl
Posts: 6
Joined: Wed Nov 07, 2012 10:44 am

Re: MK 808 dead after 1 month succesfull operation

Postby moritzerl » Thu Nov 08, 2012 1:33 pm

Same problem on my mk808 - no light - no hdmi output !
Power Supply is ok - what wrong Mail400 ? RK3066 broken any ideas ?

reddragon72
Posts: 103
Joined: Wed Oct 31, 2012 2:30 pm

Re: MK 808 dead after 1 month succesfull operation

Postby reddragon72 » Thu Nov 08, 2012 2:36 pm

If your really good at electronics you can use a multimeter to see if the power plug is bad... I have heard on several devices like this that the power(mini usb) plug has a really bad solder job and when it heats up and cools down it will eventually break the contacts. Re-soldering seems to have helped several people. I recommend that the USB power cord not be left to dangle. Those small soldering points just cannot handle the long stress of being pulled on.

also you can try wiggling it a little, and I mean just a little, because once you pull the pad off of the board you will be in for an even harder time trying to reconnect the small pin to the trace on the board. This is also an issue with some older cell phones when the port is not supported by the casing the the pins are left to do all the heavy work.

Image

moritzerl
Posts: 6
Joined: Wed Nov 07, 2012 10:44 am

Re: MK 808 dead after 1 month succesfull operation

Postby moritzerl » Fri Nov 09, 2012 1:05 am

thanks a lot for reply !!!

- i have a multimeter a will messure the voltage on the pins
but i dont think i will have sucess
- the cpu gets only a little warm if i connect the power
but no blue light .
maybe some transitstors broken ?

bayliner195
Posts: 6
Joined: Mon Oct 15, 2012 8:02 am

Re: MK 808 dead after 1 month succesfull operation

Postby bayliner195 » Fri Nov 09, 2012 4:13 am

yesterday opened the tv dongle and I tryed identify power supply control test probe positions on the printed circuit board.I don't see marked (coloured) test points, as I have seen in (in other forum) the UG802 board.
I checked the RK3066 datasheet, need 2.5V for the cpu, 3.3V for the HDMI interface, 1.1V for the digital interfaces.
Seems no necessary power inside the board for the CPU and for the other component.
Has anybody MK808 theoretical circuit drawing, esspecially focused for the necessary switching power supply unit?

moritzerl
Posts: 6
Joined: Wed Nov 07, 2012 10:44 am

Re: MK 808 dead after 1 month succesfull operation

Postby moritzerl » Fri Nov 09, 2012 8:36 am

Whats the name of the switching power unit und where is the location on board ?
i will try to measure the voltages

reddragon72
Posts: 103
Joined: Wed Oct 31, 2012 2:30 pm

Re: MK 808 dead after 1 month succesfull operation

Postby reddragon72 » Fri Nov 09, 2012 11:11 am

There is no divider.

One one side of the board you will see small hockey pucks, each of those are the coils for amp regulation. By those there are IC's and caps(grey with silver ends). Each of those IC's and cap/resistor combo's forms the regulators for each required voltage. They break this up into each one as one IC chip this small simply could not handle the power requirements. Without a sckematic or the board in front of my I could not tell you which one is which. Maybe someone with a really nice camera could shoot me nice up close none blurry pic of that area.

Now there is one coil all by itself and I believe that may be for the HDMI power, but again without seeing the board or the schematics I cannot say.

moritzerl
Posts: 6
Joined: Wed Nov 07, 2012 10:44 am

Re: MK 808 dead after 1 month succesfull operation

Postby moritzerl » Fri Nov 09, 2012 12:48 pm

yes - i see the power units - most have 5v at one site and 3,3v at the other side.
Seems the most of the power supply units are o.k - do you think the blue led is driven bei HDMI Power ?

reddragon72
Posts: 103
Joined: Wed Oct 31, 2012 2:30 pm

Re: MK 808 dead after 1 month succesfull operation

Postby reddragon72 » Fri Nov 09, 2012 12:57 pm

That is possible since most LED's are 3-3.5 V

And if the HDMI chip doesn't boot up then yea you may not know if the CPU is actually running. So you will have to test headless.....

And easy way to see if the unit is actually powering up is to go to your router and find the sticks IP addy and ping it. Or you can try and ADB shell into it. This will let you know if it is up and running. If either of those tests work then I would demand a replacement. There is no reason for it to have died out this quickly and sounds like something on the unit was defective and finally gave out. If they don't show the unit actually running I would still demand a replacement as there seem to be only two out of hundreds that are seeing an issue so it sounds like you guys were just unlucky and received defective units.

moritzerl
Posts: 6
Joined: Wed Nov 07, 2012 10:44 am

Re: MK 808 dead after 1 month succesfull operation

Postby moritzerl » Fri Nov 09, 2012 2:17 pm

thanks i will try the adb shell - really good idea !

moritzerl
Posts: 6
Joined: Wed Nov 07, 2012 10:44 am

Re: MK 808 dead after 1 month succesfull operation

Postby moritzerl » Fri Nov 09, 2012 2:40 pm

Mk808 --- lives !!!!!!!!!!!!! ----- again

Made a new Firmware update ---- adb works !!!! ---
and the blue led is burning again - and HDMI works again - unbelievable

Thanks - thanks again

bayliner195
Posts: 6
Joined: Mon Oct 15, 2012 8:02 am

Re: MK 808 dead after 1 month succesfull operation

Postby bayliner195 » Sat Nov 10, 2012 4:29 pm

Now I measured all of the coils and condensators, there are on every condensators the right voltage (5, 3.3, 1.5, 1.3V),
only at the 2R2 marked coil I can notmeasure any voltage. There are two condensatot around the 2R2 coil, at one side I can measure 5V, but on the coil and on the other condensator which loacating on the board edge there are no any voltage.
Could anybody measure the right voltage here and give any idea how can I make an auxiliery power line from a couple of smd parts?

bayliner195
Posts: 6
Joined: Mon Oct 15, 2012 8:02 am

Re: MK 808 dead after 1 month succesfull operation

Postby bayliner195 » Sat Nov 10, 2012 5:08 pm

Hi Reddragon,
Could you explain how can I do the "ADB SHELL" procedure?
Currently my problem is the Windows7 can not recognise the connected Mk808 , and the downloaded drivers not working.
I downloadad the drivers with the rk3066tool together,but it reported error under the instaalation.
Right link for the driver download?
Thnx

evildave
Posts: 21
Joined: Mon Oct 08, 2012 7:49 am

Re: MK 808 dead after 1 month succesfull operation

Postby evildave » Sun Nov 11, 2012 3:34 pm

reddragon72 wrote:There is no divider.

One one side of the board you will see small hockey pucks, each of those are the coils for amp regulation. By those there are IC's and caps(grey with silver ends). Each of those IC's and cap/resistor combo's forms the regulators for each required voltage. They break this up into each one as one IC chip this small simply could not handle the power requirements. Without a sckematic or the board in front of my I could not tell you which one is which. Maybe someone with a really nice camera could shoot me nice up close none blurry pic of that area.

Now there is one coil all by itself and I believe that may be for the HDMI power, but again without seeing the board or the schematics I cannot say.


of what section exactly you need a photograph?

gavinca
Posts: 1
Joined: Wed Nov 28, 2012 5:06 pm

Re: MK 808 dead after 1 month succesfull operation

Postby gavinca » Wed Nov 28, 2012 5:17 pm

Hello guys. I just found this thread in Google, and I'd love to ask an mostly unrelated question please. I hope no one would mind.

I am looking to purchase the PCB / board (not sure the terminology here) for the MK808. Does anyone know a good ShenZhen company that manufactures those? I'm not looking for the assembled dongle, and I'm not looking to do any sautering of USB or HDMI components. I'm simply looking for the board to be able to slip them into dongle cases. (I'm also looking for a manufacturer of cases for Android dongles!)

Has anyone had luck buying those, or does anyone have general advice here?

Peace, and thanks.

fe4r
Posts: 1
Joined: Tue Dec 11, 2012 3:04 pm

Re: MK 808 dead after 1 month succesfull operation

Postby fe4r » Tue Dec 11, 2012 8:12 pm

I'm with a little different problem. The Mk808 turn on and works (I find it in my wifi network), but when I plug the hdmi cable it stop (in the network) and the blue light turn off.

I tried a new flash rom, but nothing happens.

Any idea?

thanks

Hemiyoda
Posts: 4
Joined: Sat Dec 22, 2012 5:47 pm

Re: MK 808 dead after 1 month succesfull operation

Postby Hemiyoda » Sun Dec 23, 2012 8:14 pm

Hello, I just found this thread. Maybe an admin could move my posts from here viewtopic.php?f=18&t=1040 to this thread. ( detailed pictures of PCB there )
Last edited by Hemiyoda on Sun Dec 23, 2012 8:31 pm, edited 1 time in total.

Hemiyoda
Posts: 4
Joined: Sat Dec 22, 2012 5:47 pm

Re: MK 808 dead after 1 month succesfull operation

Postby Hemiyoda » Sun Dec 23, 2012 8:30 pm

Core supply should be 1.1V +-10% ( I wonder if each core has it's own supply since we have 2 identical supplies on the board ( edit: nope arm core has one 1.1V supply and logic&GPU core has it's own supply. See page 4 in the reference tablet design.)
IO supply, 3.3V or 2.5, or 1.8V +-10%
See page 38. http://yuandao-n90-window-dual-core-2.g ... p25_38.pdf
(also visible in the better RK3066 datasheet brief, but with more technobabble: http://yuandao-n90-window-dual-core-2.g ... _brief.pdf )

Reference tablet design that can give some hints: http://yuandao-n90-window-dual-core-2.g ... 66_MID.pdf


Maybe the DC/DC's are too weak and they have cranked 'em up to 1.4V to try to compensate. I'll have to hook up a scope to this bastard. :mrgreen:

giovanib
Posts: 1
Joined: Thu Jan 17, 2013 11:16 am

Re: MK 808 dead after 1 month succesfull operation

Postby giovanib » Thu Jan 17, 2013 11:22 am

Hi!

Did you solve your problem with MK808?
I have exactly the same problem. It worked fine for 3 days, then it stopped.


Return to “MK808”

Who is online

Users browsing this forum: No registered users and 1 guest