Phase detection autofocus not working well after motherboard replacement

Question

my unfortunate story foes like this. I broke the flash card slot in my Nikon D3300. Unfortunately it was too tiny to solder new one on, so I ended up purchasing a used motherboard and successfully replacing it.

Well, it works, BUT, now my camera only takes sharp pictures if using live view, because I assume it's using the contrast detection method to focus. When using view finder, pictures end up looking blurry.

I heard that each camera is calibrated with some phase detection values and those values are written in the memory, so I guess what happened is with new motherboard, I got some other camera values as well.

What are my options? Is there a way to transfer my old motherboard values to new motherboard? Any way to re-adjust autofocus?

Answer 1

Your options:

Repair it Yourself. The cost of the equipment required to calibrate the AF system would exceed the replacement value of the camera. The fact that Nikon doesn't make the tools required to read and store the alignment values in the camera won't help, either.

Send it to Nikon. If you send the body in for service, Nikon will likely notice that the board in the camera isn't the one it installed in the factory and may refuse to service it. If they do repair it, the repair bill would, again, probably exceed the cost of a factory-fresh replacement.

Replace the Body. This is probably the most cost- and time-effective option.

Answer 2

You probably have a "back focus" or "front focus" issue. This relatively easy to fix on D7xxx cameras which have AF Fine-Tune directly within the menus. On lower-end cameras like the D3200, the feature is not there, but not everything is lost: you can still mechanically fix it. You'll need a 2mm Allen Key, a bit of patience and a lot of caution.

Warning: this will require working just next to the sensor of your camera, you need to be careful not to damage the sensor and not to let dust enter. But if the next cost-effective method is to throw your camera away and buy a new one, there's not much to risk anyway.

I won't write a detailed tutorial here as others already did so, and you can find tons of them with the right keywords in a search engine "back focus fix", "front focus fix", ... See this one for an example:

http://www.brianparkes.com/nikon-d3200-lens-calibration/

Answer 3

Resolved. I ended up returning the other motherboard I bought, learned how to solder, and soldered mine back to working order. Camera is back to normal and works wonderfully.

Now, the culprit. Since D3xxx models don't have adjustable auto-focus values, they are calibrate on the factory unique to each camera and are recorded on the motherboard. In other words - you need to either recalibrate(Ship to Nikon), or use the original motherboard.