For the problme of “no card inserted “

1.Check whether it’s the problem of your ak2i connector.You can wipe your ak2i and then reinsert it again.

2.If the first way cant fix your problem,then check this way.Please format your micro sd card ,then assure you have download the latest firmware v1.89 and unzip it,open the folder and copy the root files into your micro sd card,not just drag it inot you micro sd card after unzipped.

If none of these ways out of work,then you have to try this recovery way

Prepare things

1.NDS/NDSL

2.any another one flashcart that can work well on your console,here i will take r4i gold 3ds as a example.

Steps

1.Download the latest firmware v1.19 and updated patch from here : Acekard 2i ,unzip them,open the folder.

2.Put akaio v1.89 files and ak2ifw_update_3ds30_DSi143_onDSL.nds on your DSphat or DSL into your micro sd card and put it into r4i gold 3ds.

3.insert them together into your nds/ndsl,and power it.

4.please eject your r4i gold 3ds and reinsert your ak2i after the update program ak2ifw_update_3ds30_DSi143_onDSL.nds on your DSphat or DSL is running. Then press B, then press START key to finish update.

Problem for “an error appeared,please hold down the power and turn it off—–” (just similar description)

If you met this problem,you can check from these two sides :

1.assure you have download the latest firmware v1.89 and unzip it,open the folder and copy the root files into your micro sd card,not just drag it inot you micro sd card after unzipped.

2.If still cant work,that’s to say,you didnt flash your card successfully,you have to update your console first

1.Download the latest firmware v1.19 and updated patch from here : Ak 2i ,unzip them,open the folder.
2. If you’re using DSphat or DSL to process this update,you should put ak2ifw_update_3ds30_DSi143_onDSL.nds and kernel files into your  micro sd card , please eject your AK2i and reinsert it after the update program is running. Then press B, then press START key to finish update.
3. If you’re using DSi or DSXL or 3DS,you should put ak2ifw_update_3ds30_DSi143_onDSi_and_DSXL_and3DS.nds and kernel files on your console, please press START key to finish update.

Above article just a summary from  my own experience,not so professional,yet,just for sharing and hope it will do little help for those who needed it. =)