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Unreliable Push-Push Micro SD Card Holders
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Please be positive and constructive with your questions and comments.

Unreliable Push-Push Micro SD Card Holders

by amarch on Wed Dec 06, 2017 6:18 pm

There is an issue with the SD card holder/mechanism. On some screens, it will not read the SD card I put in (even though the same SD card will work on other screens). Sometimes I can hear an audible short happening when I attempt to initialize the SD card in the firmware - it creates a high-pitched whine from the SD card holder and intensifies if I press down on the holder.

I am experiencing this problem with about 20% of the screens that I was shipped (and one of the screens was cracked out of the box)!
Do you have protocols for fixing the micro SD card holder? Furthermore, a lot of SD cards (Sandisk, Samsung, Kingston) simply have problems reading. I have some experience with micro SD card holders and these spring loaded ones that are on the screens really suck. But since they are already there, what do you suggest I do to salvage the units that I already have?

Thank you.

amarch
 
Posts: 5
Joined: Mon Nov 27, 2017 3:56 pm

Re: Unreliable Push-Push Micro SD Card Holders

by Russell 27 on Thu Dec 07, 2017 10:43 am

micro sd socket.png
micro sd socket.png (260.94 KiB) Viewed 194 times


Generally when using a micro SD card socket in a project I hand solder it. This way I know all pins have good connections to the pads and all flux and debris can easily be cleaned away. To do this the top cover must carefully be popped off (with an exacto blade), on one of the sides where the small latches snap in place. If done carefully the spring mechanism will stay in tact. I've never had a problem with pad connections using this method. Now you may not want to go to all this trouble or need to. Take a look inside the sd slot opening with a light and magnifier and check for excessive flux or any debris keeping the card from contacting properly. You could try cleaning with compressed air or a small brush and alcohol. I'm sure these were solder flow baked, one or more of the pads may have a bad or cold joint. If you are a solderer, you could try reflowing with hot air, or the technique from above. Sometimes the metal case is a bit tight or not registered quite right and the spring mechanism is a bit sluggish, or again debris. Not all SD cards are created equal, some require more start up current. I have an older project that will only accept non HD cards formatted to FAT file system, which are hard to come by these days. One of these may prove a personal solution.

Russell
Russell 27
 
Posts: 240
Joined: Thu Sep 12, 2013 3:59 pm

Please be positive and constructive with your questions and comments.