Hardware O3DS doesn't boot, makes 'click' sound and turns off

[ClickCLK]

Hi. I got old 3DS, which I got on release (preordered on amazon), which came to me with firmware v 1.0.0-0e. I never really played it (total working time - less than 12 hours), and it was laying on a shelf until ninjhax came out. Before updating and installed ninjhax I opened it up to dump its NAND, which was succesful, then updated it new firmware (I don't remember the version, the one which was available on ninjhax release), installed ninjhax that went ok too. But when i started to assemble my 3DS back I suddenly dropped it on the floor from ~70cm height and broke flex cable to the R button in half. I tried to turn it on - everything was working (except R button hehe), so I decided to repair broken flex cable while waiting for new one to arrive from China, so I took it to my workplace (I'm an cellphone/laptop repair technician).

When i got to work I tried to turn console on again - and it didnt. Blue power led lights up and after a couple of seconds 3DS 'clicks' and turns off. I heard this can happen because of broken flex cables to both screens, flex to speakers, flex to cameras or disconnected wifi module. I dissassembled the console completely, checked every flex cabled under the microscope - there were no cracks, tears or broken traces (there were some places which looked jammed, but under the microscope I saw they weren't broken). The only thing that made me suspicious was a connector for bottom screen flex (which is on main board of the 3DS), there were some deformed pins in it. I ordered new connector from China, soldered it on board (in place of old one), but it still doesn't turn on.

What am I doing wrong? What else can cause this problem? Also, what needs to be connected for 3DS to turn on? Please help me, this console was almost new...

Btw I'm good at soldering, so I really couldn't screw anything up when I was soldering the connector.

Edit: I forgot to mrniton that I also checked this fuses, and they are ok.

Spoiler

 

[SmileCitrus]

The only two things that really need to be connected for the 3DS to boot are the two backlights.

The system will still boot even if the only two cables connected are the speaker cable that goes into the P7 connector and the small cable that goes into the P12 connector on the motherboard. The actual LCDs can be unplugged and the system will still boot. If the WiFi module is unplugged or damaged you may only get a solid black screen, but it won't cause the system to make that clicking sound or turn off.

One important caveat though is that the other end of the speaker cable does actually need to be connected to the upper screen backlight in the top half of the console for the system to boot. If this little connector in the photo below that connects to the top screen backlight is damaged or broken, the system will click and turn off when you press the power button.

The only thing that made me suspicious was a connector for bottom screen flex (which is on main board of the 3DS), there were some deformed pins in it. I ordered new connector from China, soldered it on board (in place of old one), but it still doesn't turn on.

Go into a dark room and try to power the system on. If the bottom screen flashes, then the problem is that the connection to the top screen backlight is broken. If the top screen flashes or if neither of them flash, then it may be a problem with the lower screen backlight or the P12 connector. Definitely double-check that this small connector is good, since it's one of the two that could cause this problem.

 

[ClickCLK]

Huge thanks SmileCtrius! Posted this thread and forgot about it, this was stupid of me.

I checked in dark environment - both screens wasn't flashing, but after that I found out that backlight flex on bottom screen is teared. Can top display not flash because of bottom one broken or it means that top one broken too? I don't have access to soldering equipment right now, as soon as I'll get to it I'll fix this tear with jumpers and will reply if it helped.

Again, huge thanks to you, this is very valuable info for me.

 

[SmileCitrus]

Glad you found the problem

No, the top screen is probably fine. I think I was wrong when I said the top screen would flash. I just checked on a console with a good upper LCD and speaker cable and the top screen did not flash when I tried to power it on with the lower screen backlight disconnected. I was probably thinking of what happens with DS Lite consoles, but maybe not 3DS.

 

[ClickCLK]

Glad you found the problem

No, the top screen is probably fine. I think I was wrong when I said the top screen would flash. I just checked on a console with a good upper LCD and speaker cable and the top screen did not flash when I tried to power it on with the lower screen backlight disconnected. I was probably thinking of what happens with DS Lite consoles, but maybe not 3DS.

So sorry for a late reply, but your post save my console. I managed to repair broken backlight flex and it worked like a charm - my system booted up, greeting me with 9.2 fw! It was a pain to assemble it back (when I searched for problems I even dissassembled upper screen completely, down to backlight layers under metal housing of lcd assembly), especially placing flex cables for upper screen, speakers and camera back to their place, but now it is fully assembled and working, I even installed rxtools fw on it.

Again, huge thanks to you. Much appreciated.

To mods: can you please mark this thread as solved and close it?