What could/would cause a SIM card to belly-up? [Telecom]

SIM cards sometimes just fail.

If you take your phone into an AT&T store, they should give you a new SIM at no charge. Before you leave, be sure the SIM and phone work, and also be sure that they didn't also change your service plan or its expiration date.

R's, John

Thank you for the excellent advice!

For the curious, the local AT&T Store had a queued service line, and after I reached the front it took only seconds to receive a new free SIM card and test call my phone. All info in the phone, even the list of incoming calling numbers, was preserved. Amazing.

The service rep returned the original SIM card to me, but it's probably not worth trying to open it and see what's in there given it's hardly more than a thumbnail-sized sliver of cardboard.

Anecdote, Thad, w/ another carrier: as an unintended consequence of "regular maintenance," a data-base entry for me and my SIM got "reset" on my carrier's systems. A call to Customer Care got that entry properly set again -- my IMEI and my phone number had gotten unlinked one from the other, and until they were relinked I was "dead in the water." Keyword/phrase for my carrier turned out to be "HLR" -- "Home Location Registry" -- that's where the trouble lay.

For your carrier, neither that keyword/phrase nor the nature of the problem I describe need be of any relevance, of course, i.e., YMMV :-) .

Hope you get it sorted out :-) . Cheers, -- tlvp

-- Avant de repondre, jeter la poubelle, SVP

SIM cards are just like all other solid-state memory devices, they all still have a finite amount of Write cycles before they fail.

The technology is steadily improving in this area, so something made today has (as a generalisation) far more Write cycles in it than things made just a few years ago.

There are Linux distros designed for solid-state drives that minimise the write cycles that are quite acceptable for normal hard disks, but will prematurely kill off solid-state storage.

SIM cards fail, USB stick drives fail, MP3/4 players fail - all because they are based on an underlying technology that has a finite life when used.

You're lucky, Thad: some phones' "internal" phone books are actually written to the SIM, ensuring that the entries aren't "lost" when transferring the SIM to a new handset. Same for their SMS messages.

Cheers, -- tlvp

-- Avant de repondre, jeter la poubelle, SVP

Sigh, I wrote too soon after realizing I didn't have to buy a new phone.

Some numbers are, in fact, stored in the phone along with a bunch of other things, but most numbers were on the SIM.

I suppose I should consider myself lucky to get 5+ years' use out of one SIM. I didn't realize how many times the SIM gets re-written in normal operation, and that's what wore it out. Even when no calls have been made or received, "something" gets written and that's what happened to me: the phone was OK when I went to sleep for the night, then 3 hours later it beeped, awakening me, and displayed "Check SIM".

I'm still looking for a SIM card reader that won't destroy the SIM. With that, it should be easier to backup/restore SIM data than the poor software from Motorola (similar to how I remove a CF card from any of my DSLRs and place it in a card reader to transfer pictures rather than connect the DLSR directly over USB) -- using the CF in a reader is akin to using it simply as a removable disk (vs. the complex and kludgy USB camera interface)).

User reports of many/most SIM card readers are horrible from what I've seen so far, and those whose specs seem good are located in the far east (per a whois) and don't sell over the web as far as I can tell from their webpages.

Does anyone here have a recommendation for a SIM card reader?

The SIM can only store a small set of numbers, compared to the size of most phone's Addressbooks. It can also only store a few items of info. While the SIM's phonebook entries are nice to carry over a few entries, most people have alot more info and way more entries than can be stored on the SIM card now. All the addressbook numbers that carried over for you were stored in your phone's memory..

Yes, info gets written out to the SIM card (ie. call logs). Mine is still going at 5 years+ now. Don't expect it to last forever, although its gone through a few phones already.

This is where things aren't going to work for you. The SIM card is not static storage. It has a processor on it with a crypto engine, as well as some storage.

You can read the information off of it, but you can't duplicate it, nor create a copy of it. It sounds like you want to create yourself a backup plan in order to restore data, but going to the store is your only way to get a working SIM again.

All the contact list info is really stored in your phone memory instead.

Although you'd have to do some soldering on the kit there.

***** Moderator's Note *****

Please tell us how the encryption engine prevents duplicating the SIM. TIA.

Bill Horne Moderator

There's just the barest of chances your AT&T store may have one they'll let you use on premises.

Or they may offer what T-Mobile included in the package when they sent new T-Mo SIM cards for our two phones (and a request that we replace the old SIMS with the new ones), viz., a SIM copier, with slots for origin and target SIMS, and a START button for starting the copying process.

Of course, if your handset thinks the SIM is flaky, such a copier may well think so, too :-{ . Still, worth asking about ... .

Good luck! And cheers, -- tlvp

-- Avant de repondre, jeter la poubelle, SVP

About 15 numbers survived because they were in the phone's memory. After some arduous Googling, I discovered the RAZR V3 can have 1000 entries in its Addressbook, but nothing as to how many can be in the phone and how many on the SIM. Neither the hardcopy manual, five different PDF manual versions, nor the official Motorola Repair Manual for the RAZR V3 give any more info in this regard. The "Installing the SIM Card" says only "Your Subscriber Identity Module (SIM) card contains your phone number, service details, and address book and message memory." That's it.

Nowhere in the manuals is it even shown that one can choose to store address book entries in the phone or on the SIM, and the V3 software itself defaults to storing addressbook entries on the SIM though one can select "SIM" or "Phone" when saving new or edited entries. And there's a capability to move them between the SIM and the phone.

Basically, all Motorola documentation about the SIM is poor and lacking, and there's nothing better on the AT&T website(s). Moto documentation is even worse than the Motorola "Mobile Phone Tools" which claims to sync between a PC and the phone in a very non-obvious way last time I tried it a few years ago.

Some info I found elsewhere claims the processor's duties include separating areas of the SIM for different purposes, and crypto.

New entries STILL go to the SIM by default. I have to manually change the destination each and every time; this is a very poor design, though I can understand why some people may want the address book on the SIM if they're moving the SIM around to other phones (which, apparently, a lot of people do: one phone for work, one phone for evening, one phone for the car, etc.).

OUTSTANDING! That one looks great, kit and parts are USA-made, and the software is for Linux, Mac and Windows. I will order it right after sending this message. RS-232 serial is not a problem for me. :-)

I've built 100s of Heathkits and many things of my own design; you might get a kick out of seeing this:

.

Thank you VERY much for the reference to that kit!

I'm not sure Doug will see or saw your moderator's note, so ...

One thing I learned is the SIM's onboard CPU controls who/what has access to certain portions of the memory. Some carrier info can only be entered once and never changed. An addressbook can be read and written. Etc.

One good site I found is this one:

Some other good info is here:

FWIW, the SIM only has 6 contacts so the I/O is serial. The contacts are CLK, RST (Reset?), Vcc, I/O, Vpp, and GND. I should be able to provide more info when I receive the kit that Doug mentioned and "play" with the software which is all FOSS. The kit's user manual is here:

Source code:

requires: and:

SIM Reader schematic in PNG:

One additional thing I just now noticed in the RAZR V3 Repair Manual is there are DSPs and other circuits to perform addition encryption as can be seen in the block diagram I extracted from the manual:

My local store (Grant Rd, Mountain View CA) didn't; I asked. :-)

Perhaps. I had a laptop with an IBM Travelstar HD that "suddenly" wouldn't boot any more or even recognize the disk -- this is a common problem with IBM/Hitachi Travelstar HDs as I found on the 'Net. Using specifically a NexStar 3 external USB drive case (and none of the other

5 brands I tried), I was able to read everything off that HD with zero loss, and the HD works fine in that USB case but will not be seen by any of my laptops if mounted inside. Go figure. :-)

I may luck out with the SIM reader Doug McIntyre cited (and which I'll be buying in a moment). If not, at least it appears to be an easier way to backup the SIM after I rebuild the address book; luckily, most of the numbers I need are in saved email, and others (for restaurants and stores) can be found on the web or in a phone book, so it's no big deal, just annoying.

I still don't fully understand why, over 5 years, about 15 numbers were saved in the phone and about 100 or so in the SIM (knowing (now) that storage into the SIM is the default).

Thank you!

That's the size of the phone's memory. The SIM's memory is what ever size it is. Newer SIMs have more memory than old ones.

That's odd. I've had lots of moto phones and they all stored stuff to the phone. There's invariably a menu option to copy the phone address book to the SIM and vice versa.

R's, John

The SIM has a crypto key that's not externally visible. You can tell it to use the key to encrypt stuff, but you can't get the key out.

This is a reasonable feature, since part of the point of a SIM is to uniquely identify the account to which calls are to be billed.

R's, John

On Tue, 22 Sep 2009 07:24:58 -0400, what Thad Floryan wrote ended with:

With my current ancient Nokia 6610, which allows me to specify whether I prefer SIM or Phone memory to be used for address book entries, even if I choose SIM any phone number that's too long (or too complicated) for the SIM to store without truncation gets stored on the phone instead.

("Too long ... complicated": one with several PAUSE or WAIT entries, for example -- 1-800-123-4567w456456456p789p123, or the like.)

Or perhaps they're numbers you once just decided (too long ago to remember doing so, or why) to move to the phone's memory area.

Also: the RAZR in particular, as I recall, will permit VoiceDialing (or do I mean one- (or two- ?) digit "instant" dialing instead?) only for numbers stored in the phone's memory, not for those stored on SIM. Perhaps *that* is why those 15 or so are in the phone?

Cheers, -- tlvp

-- Avant de repondre, jeter la poubelle, SVP

BINGO! That's exactly correct. Those were numbers I entered with the "Voice Dialing" option way back in 2004/2005. I had actually forgotten about that capability (and pictures, videos and other stuff associated with any given number) forcing numbers to the phone's memory (5MB) vs. the SIM memory (64KB) since I don't use the phone while driving except for a 911 call. That also explains the "odd" icon alongside those few numbers -- Motorola docs (for the RAZR) are not really comprehensive.

Thanks for the feedback, Thad -- it's rewarding to learn that I can still guess right once in a great while, these days :-) .

Cheers, and may your new SIM serve you long, and in good health,

-- tlvp

-- Avant de repondre, jeter la poubelle, SVP

New SIMs are typically 32K or 64K. The larger SIMs don't necessarily have that much more space to store names and numbers (which is the only variable data that you can input into a SIM... any other information such as alternate numbers, email addresses, notes etc. cannot be stored on the SIM but rather have to be stored in the phone's internal memory if it has it.)

I can't speak to Moto phone's behaviours but on Nokia you have three choices: store to phone or SIM with a setting that will let you read information from both if desired, but additional entries all go to phone memory. Usually there's a default setting for when you add entries. Default from the factory is usually to the phone's memory.