MP4 Hyudai 512MB - Accidental OverVoltage
 

Hello! I have a little problem with my MP4 Player Hyundai Brand 512MB

This is exactly how is (included the same types of headphones):
http://upload.wikimedia.org/wikipedi...yer_1_zear.jpg

This is a similar model:
http://www.lakewoodconferences.com/d...MP4_Player.jpg


I was repairing a CD Player and I needed a source of Music, my idea was to input the music signal into the Integrated circuit of Amplifier. The Signal music was my MP4 Player through a cable from Headphones Output to Integrated circuit.

Accidentally I touched a +12V line with the cable from MP4's headphones output... and it suffered the "high" voltage impact.

The screen was crazy, unestable, for a few seconds, and it show LOW BATTERY and turned off.

Some minutes after, I turned on again, the screen was crazy and unestable again (almost unreadable) and turned off.

Now I can't turn on my MP4 player. It never turn on again :(

* What can I do?
* What do you think about this failure?
* I would like to fix it, I think maybe some fuse or reglator... but what can you advice me before start to trying fix?
* Are there some Schematics that I can use?

I'm expecting you comments ;)
All comments will be welcome :)
(sorry for my bad english)

well first of all there are no fuse in these mp4 players.To start with is that you must be using the DC POWER SUPPLY so open your player and take its battery out and put the + and - cable in the place of battery in the MP4 and power ON the supply with the 3.7 volatge and then power ON the MP4 and then see it remains power ON or not and how the screen come and what the supply is doing ........mean the voltage is dropping or they are stable..........and you can also put your finger on the components on the MP4 to get the idea if any component is over heating.This from where you can start........... i think

Ok... yesterday I downloaded some schematics, last night I ran to my house and try with your advices:

I connected the Power Supply to my MP4 but there is not response... no Power supply present, no signals of life!

Then, I took my screewdriver and opened the unit. I removed the battery and connect the power supply again... but there was not response.

I connect the MP4 to the computer with the USB cable... no response and no drive or USB device detected.

Then I open some schematics and looked for some ideas... then I found some tutorials about repairing, and one of these said: 'Make a Shortcut between the capacitor lines (I think is a Crystal) for a few moments"

Ok... I tried this... the MP4 connected with the cable, and shorcutting the capacitor... and Oh surprise! in the Icon tray (near Windows clock) in computer, appears a message: "Some USB device is connected but is mal functioning" or something like that...

Wow! :shock: :shock: A little hope of life!!! :wink:

Then I check the ATJ2085H chipset pin diagram:

And I found the RESET pin... I shorcutted this pin with VCC and GND... and OH SURPRISE! The Mp4 turned on!

The Computer recognize as a Storage Device, and run the autorun... I opened the device and I can retrieve some old files and lyrics.

The MP4 was in charge/sleep mode, but suddenly the unit Turned On to the MAIN MENU.

The menus were Ok, I tried to play some music, but when the music plays the screen was unestable.

Suddenly, the MP4 return to the Charge/Sleep mode, but now with the Unestable screen.

Then, I disconnect the MP4 but now the unit won't tunr on. Is dead again :(

I think maybe some chip need some RESET or something like that.

* Can you please advice me something?
* Do you think my MP4 player can come back to life???
* Reviewing some notes, Now I can identify some aditional data: The board type is a MP680-CL-V11, with Chipset ATJ2085H and a Flash memory SAMSUNG K9F4G08UOA.

Here some pics: (may be usefull)

Thank you for your comments ;)

well dear if you exlapin it to me without the pics then it is more easy for me to understand i know what player you have ......... so please explain me in some easy way

Ok:

I have a board MP630-CL-V11. I need to make a "Total Reset" by any possible way: A shortcut in some chip, a new reprogramation (Upgrade firmware) or something for come back from the dead state.

What can you advice me?

That component is not the CRYSTAL it is the osscilator and in your problem first of all change that osscilator becasue that is controlling the power on function and the usb control too.The screen is unstabe is not the big problem first is that the player have to be stay alive..... and dont short the atj2085 chip becasue it is working well for the moment

Ok thank you very much, I'll try to change the oscillator on the Weekend. I'll come back Monday with some notices ;)

By the way... Do you know How can you make a Backup copy of your actual firmware?

Greetings!