How to replace a Nikon D750 Logic/Motherboard 

When the camera gets beer in it you know it's a heck of a party!

I'm stuck at the eye piece screw, mine is just a twist positive negative for the eye piece how do you take it off?

Ok it was a sticker...now how do you unplug the flex cables???

@@RickLaw101 There's a plastic sticker covering the screw - use a sharp point to lift the edge, exposing the screw.

@@RickLaw101 Watch the video. The connectors are of a standard type - if you're not familiar with them, an expensive DSLR is not the time to learn.

@@LostNimrod Hey there, thank you for the reply. I actually just finished and it actually effing works! I spent about an hour on a stripped wifi screw, ended up using a rubber band and a power drill to get it out. Then the flex connections were easy once I saw how they just flip up and down. Next is replacing the grips, they're all coming off...Thanks again!

I just looked up your problem and it doesn't seem to have any battery in it that can be replaced easily. It's not on the motherboard as I just looked at the dead one and checked. I am betting it's soldered on a smaller board in the unit. They are usually little button cells about 7mm by 2mm ish and all silver. They can fail and it's common. I can't find a good page that shows the location sadly. But if I do I will let you know. I have no idea when I would be working on another camera, that depends on when the next one comes in. If you're in the US your eligible to send here if Nikon can't/wont fix it or if you cannot find another repair location. I'll most likely to be able to replace the battery, Though my specialty is in laser/lighting technologies. Figure cost most likely be in the $70 to $100 range the battery price is negligible and included in that.

Hmm, that is an interesting one. I wonder if it could be an issue with the data pin on the battery not making connection correctly. It would also be the internal back up battery but usually that still lets you use the camera. Aside from that I don't know of any other issue that would cause this.

@@Zenodilodon thanks for the reply. Where can I see the date pin?

@@102591fred Apologies, I meant data* I don't recall the exact pin but it's usually the smaller center pin/contact.

I connect all the pin correctly. I read about this problem, they say it need to update the firmware. Do you how to update the firmware if there is no display showing?

@@102591fred I do not, I am a laser/analog electronics technician by trade. What I know about firmware of sorts might fill a post-it. You will most likely have to look for the firmware files and find the instructions for installing them. I would check on official forums or attempt to locate the software on Nikon's site. With older devices these files can often be tricky to find. It's strange that you have no display. You may have a board with other issues. Continue searching and best of luck!

It's a sticker from what I remember, I think I ended up mucking it up myself but I am betting a little rubbing alcohol and a little plastic pry tool might help you get yours off a little better. The owner of the camera did not care about the little sticker/piece so it was never replaced.

The board was purchased off ebay, the price hangs anywhere from $90-$150 depending on the listing.

greatly appreciate it! and I greatly appreciate this video also!!!!!@@Zenodilodon

I did not get that far into the camera. If you have soldering skills any battery should be replaceable. If the battery isn't one that is externally accessible it may be located soldered to the upper button board, though gaining access may be tricky.

@@Zenodilodon thanks.. judging on main board it doesn't seem to have the battery in it.. I cannot find any post that is related to it for a fix

@@meronmeron-m3m I checked the fried board I have here still and there isn't a battery on it from what I can see either. I don't know why some brands have batteries hidden away like this, though I doubt it's for your favor lol.

Thanks for the information, I would of never known about the switch to CMOS otherwise. it's not something I have looked into. Generally I don't fix cameras all to much but I break quite a few. This is mostly cell phone cameras though. The lasers tend to be quite hard on camera sensors and I would feel quite badly for cooking a nice one. If another camera comes in for repair or I just find an interesting and unfixable one I will certainly post that up as they are fascinating.

When you say vienw finder do you mean the LCD or the lens you look into? If your camera took a hit like that it could of very easily unseated a cable. This could be the problem. Both the LCD screen and the image you would see are made of glass. The view finder LCD is a bit different so damage would be hard to spot but you can carefully try to spot any glass cracks.If you see none best option is to open the camera and check the connections. My only other thought is that it could be a torn ribbon cable which can turn into identifying what part that goes too or links with in order to find a new replacement.

@@Zenodilodon Thanks for the answer. I was referring to "the lens I look into". I didn't notice any cracks. I was thinking about disconnected cable or broken electronics. I didn't find any video on RU-vid teaching how to open the machine up to this point. I'll take my chances and open up. Is it too complicated? The rear LCD is ok. Thank you for your help.

@@eemacedo Getting into the camera is the hardest part because of hidden screws. From there it really is a matter of what part goes where. The best advice I can give you is to go at it without hesitation and to be in a good state of preparedness. Take pictures or videos of what you do so that you have absolute reference of how things where, leave nothing to guesses. Make sure you have all the tools for the task mostly in this case a few small screw driver kit. I find putting parts in a cupcake tray and such helps with keeping track of everything. It's a mental state.You should do just fine if you can already get as far as in the video.

@@Zenodilodon Wow, thank you very much for your help. I'll try to resolve this on a good day. Here in Brazil technical assistance is very expensive and takes a long time to repair. I hope it's just a loose thread. When the camera fell, there was a crack at the front and back. So I found your video, because I ordered the front and back of the camera on AliExpress and expected to learn how to open the camera. However, your video will only show until the main board is changed. From now on I will have to do it myself, because I did not find any video teaching how to disassemble the whole camera.

@@eemacedo Help out others and try to get some video up on RU-vid, this has been a popular topic and there have been many asked questions on how to work on it.

I would think so. The motherboard is the only component that has memory on it from what I see so all settings,calibration, and counter information should all be stored on that.

I am not sure myself, I did not work on that section of the camera. Sorry :(

@@Zenodilodon thanks you. I make the mistake tobtouch the mirror in my d750. Its there anyway to change the mirror in the cam?

@@alexsimon443 Yes, you can replace the mirrors if you can locate one. Otherwise get a very soft microfiber and some pure Isopropyl alcohol to clean your mirror as best as possible. I would also advise cleaning your hands first as well to remove oils from your skin as best as possible before handling the microfiber.

@@Zenodilodon well, I have waranty for the product. Will I loose my waranty because clean the mirror?

Are you speaking of repairing the spring loaded ejection mechanism in the SD card slot on the board?

I looked up pictures, there seems to be full replacements online. It looks like there is a pin that is in the frame it must slid out, looks like there is a clip on the bottom of the bracket that once pulled from the camera will clip off allowing you access to slide the pin out. From there the spring should be freed.

ae01.alicdn.com/kf/HTB1fZ4CaAfb_uJkHFrdq6x2IVXaf/Repair-Parts-For-Nikon-D750-SD-Card-Slot-Cover-Door-Memory-Chamber-Lid-Ass-y-With.jpg_640x640.jpg

@@Zenodilodon I found the whole replacement and purchased it. I thought it would be easier to just slide out the top door but I am stuck. I then was trying to figure out how to take out the old one and do the full replacement. I have the parts already just haven't figured out how to get the old one.

@@estearns369 Without the camera directly in front of me it's hard to say, it doesn't look like it's held in by much. How far into the camera have you gotten? It's a relatively easy camera to work on, hardest thing is keeping track of the screws, a muffin tin works well. Best advice I can give ya is patience and caution. Another thing I also do for most anything I take apart that is complex is to record what I am doing so if I do get stuck I can review footage and that often helps as well.

Good question, I took a look at the board and there seems to be no location for a battery to be plugged in nor a little soldered battery on the motherboard. I did note I had to reset the date and time on the camera. A google search suggested to look for a small battery door inside of the main battery compartment. Something similar to this. advancedphoto.com/what-my-digital-camera-has-another-battery/

I've found it's easier to take a part a camera than to put it back together, it's one of the few things a sort tray is nearly a requirement.

Sorry I have not been getting all my notifications for comments, you may contact me through email Zenodilodon@gmail.com or though FB /Zenodilodon