Chosen Solution
So, I know this problem is usually related to defective ribon cables, but there are quite a lot of ribbon cables in there and I’m not sure about which one is defective. My 3DS also wont show image when it is only opened a bit. I tried removing and reinserting all the ribon cables and it didn’t make diference, so I’m guessing the problem is not with the conectors. I also checked continuity in the fuses and they’re all good. After testing a bit it seems that the pop sound comes from the speakers, since there will be no sound when they’re disconected from the mobo, but it still wont turn on the screends. I also tried disconecting the camera and the top screen and the console would still show no image and it would turn off little after being turned on.
Here are the steps I take when diagnosing this problem: Step 1) Make sure the battery is fully charged…this just ensures that the diagnosis is accurate. Step 2) Take the console to a very dark room. Push the power button then put your finger over the blue light. Watch the screens to see if either of them flash. Step 3) If the top screen flashes then you most likely have a problem with the lower screen ribbon cable. If the bottom screen flashes then you probably have a problem with the upper screen ribbon cable. If no screens flash then you most likely have a problem with the speaker ribbon cable. Step 4) After diagnosis check the ribbon cable. Most of the time you will find the problem to be the speaker ribbon cable. A lot of times this ribbon cable gets a small tear right where it goes through the hinge. Sometimes you will find corrosion (or just find them loose) on the two ribbon cables that come out from the top screen. Also, if this console has been repaired before sometimes you will find that when the previous repairer installed the ribbon cables onto the motherboard then damaged them near where they connect to the board. BTW, this problem is not caused by fuses. The fuses on the 3DS hardly ever burn out. I hope this helps.
