Good News !!! SIM CARD MOD IS HERE !!!

b_force said:

Totally different question from my side, but what are the (major) differences between the Phonton Q and the Droid 4?

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1. Droid 4 bootloader can't be unlocked
2. TI has left the phone/tablet CPU business (unlike MSM8960, OMAP4 can be already considered a legacy SoC)

kabaldan said:

1. Droid 4 bootloader can't be unlocked
2. TI has left the phone/tablet CPU business (unlike MSM8960, OMAP4 can be already considered a legacy SoC)

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3 the D4 has a bright but poor pentile LCD panel while Photon's one is a nice RGB one


4 D4 lacks the useful camera button, while Photon lacks the useful physical navbar

The Solutor said:

4 D4 lacks the useful camera button, while Photon lacks the useful physical navbar

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Google design specs and recommendations. Navigational hardware buttons are being abandoned.

mrvek said:

Google design specs and recommendations. Navigational hardware buttons are being abandoned.

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Google is free to do whatever dumb move, as I'm free to dislike them.

Can we get back to topic, please?

mrvek said:

Google design specs and recommendations. Navigational hardware buttons are being abandoned.

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Not by Samsung.

Sent from my Photon Q with Tapatalk 4

Hi, CornholioGSM, I wanna buy a logicBoard with the sim mod, can you send it to Mexico?


Enviado desde mi XT897 mediante Tapatalk

pc-coholic said:

Together with a collegue of mine, we are currently doing exactly this: designing a flex-pcb (0.15mm), that has a nano-SIM-socket. The special thing: The nano-SIM-socket is a "push-push"-type and does not require a tray for the simcard.

Additionally, the SIM-socket is so small, it even fits the phone without removing the small shield on the phone.

Currently, we are waiting for some more sockets from the company who produces them, as they are not available yet from distributors...

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Well, that sounds like a very good idea!
Keep me (or maybe us) informed if you can
I'm seriously interested in it, almost seems to fit exactly my thoughts.

Otherwise I think I indeed will buy a sample or the real think and find a solution.
But still, if someone can give some measures, that would be great

b_force said:

But still, if someone can give some measures, that would be great

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Here you are...

Keep in mind I'm not from Swiss , measures are taken carefully but some imprecisions may be still there

@CornholioGSM

please if you find a while look to your PM box

Likely I have an answer to the puzzling SIM card error, reported by many users.

As I wrote in message #1001 I was unlucky with my photon, it had poor sensitivity, I checked and redone the mod many times, I checked everything else and I finally realized that my work had nothing to do with this. I got a faulty board, that's all.

BTW due to various personal issues (and a bit of laziness) I postponed the board replacement until few days ago.

Now I moved the mod to a new logic board and the missing signal bars are now back.


BUT


this time I have the infamous SIM error at least once a day, sometimes twice a day.

Hardly the culprit is the SIM slot, as guessed by other users affected by the problem.

Firstly because the SIM and the SIM slot are the same used on the old logic board. And in the old logic board I haven't seen the problem a single time in six months.

Secondly because, often, the problem appears overnight when the phone is sitting w/o any vibration that can affect a poor contact.

Given that I can exclude any temperature problem too.

So I asked myself why the original mod (done relatively poorly) was working perfectly, and the second one (done way more carefully) isn't working as expected. ?

Finally I realized a difference between the two: on the original mod I lost the resistor labeled 1712 in picture taken by Cornholio and I shorted it, while in the actual mod all the original components are in place.



Given the SIM contact where this resistor is connected is the I/O pin (read the main SIM pin) I'm almost sure that the lower resistance makes the difference, likely because the resistor is calculated by Motorola engineers taking in account a way shorter electrical path, and w/o the added contact resistance that is higher on a contact than a soldered pin, no matter how good is the SIM slot.

In the next days I'll short that resistor on the new mod too, and I'll post if my guess is correct.

The Solutor said:

...

Given the SIM contact where this resistor is connected is the I/O pin (read the main SIM pin) I'm almost sure that the lower resistance makes the difference, likely because the resistor is calculated by Motorola engineers taking in account a way shorter electrical path, and w/o the added contact resistance that is higher on a contact than a soldered pin, no matter how good is the SIM slot.

In the next days I'll short that resistor on the new mod too, and I'll post if my guess is correct.

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Interesting, thanks. I'm looking forward what the outcome will be.

My status:
My 1st Photon Q modded by Cornholio a year ago worked without a single issue for several months while using T-Mobile SIM, until I changed my mobile operator and let my number to be transfered to Vodafone. Since I started to use Vodafone LTE SIM, the SIM started to fail, sometimes several times a day, sometimes once in several days.

At the time I made this SIM switch, I also ordered 2nd Photon Q (dedicated for CM development, so I could freely experiment while keeping one of the Qs always operational, as I'm using it as my daily driver).
Cornholio modded this 2nd Q for me using better card holder than in the first one and also offered to remake the 1st one as well. But I haven't found the time for the remake so far.

The Vodafone SIM in the Q with the 2nd revision of mod works more reliably than in the 1st one, but the card still occasionally fails.

As I've had also one older, mostly unused prepaid T-Mobile SIM, I've put it in the 1st Q. With this card, there are zero failures again.

So I'm pretty sure that the issue is electrical. Card holder can contribute to it, but the most important factor is the card type, its sensitivity / electrical characteristics.

The failures usually happen at places with poor signal coverage, where the phone often switches between several BTSs while all of them have poor signal. And it usually happens to me during a phone call made at such place. As soon as I go out from the basement to a place with better coverage, the SIM does not fail during calls. As long as I stay at that poor place, I can hardly finish any call, it's almost always sooner or later interrupted by SIM failure.

Hence I guess that the failure usually happens while the phone is switched to max TX power and is actively transmitting.

So my hypothesis is that it's the interference from antenna what's disturbing the communication line to SIM. (The main antenna is located at the bottom edge of phone, exactly where we put the SIM holder.)
The removal of that resistor could increase the signal to noise ratio on that line, so it indeed could be a viable solution.

I've also considered another way how the card could be brought to failure. The reset pin has to be held up. When the voltage on reset line goes below a threshold for about 100ms, SIM reset is triggered. Such reset would cause the card to send Answer_To_Reset to modem, which would be regarded as SIM failure by the modem if it wasn't the modem firmware who actively issued the reset to the SIM. If what happens on Reset line would be the cause of SIM failures, we could try to use lower resistance of the Reset pull-up resistor. But this is just pure speculation.

I still have my photon q buts the screen is cracked...battery ribbon broke and sim solder was a failure..lolol... wouldn't mind bringing it back to life but the cost...

Sent from my SM-N900 using xda app-developers app

kabaldan said:

Interesting, thanks. I'm looking forward what the outcome will be.

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Maybe is to soon to speak but I shorted the resistor and looks like the problem is gone.



@CornholioGSM

I wrote you a PM about a different matter, did you read it ?

CornholioGSM said:

...i must say that i use approx 7 months better thicker wires (0,3mm) and alps slots and all modded photons from this time works without problems.

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As I've said, the 2nd Q modded by you at the beginning of September is much, much better than the 1st one in regard to SIM stability, yet I'm still getting occasional SIM failures when using the LTE uSIM by Vodafone CZ.
I suppose you've already used ALPS slot and thicker wires on it. Can the difference between wires be easily seen? I'll open it and check it.

The Solutor said:

Maybe is to soon to speak but I shorted the resistor and looks like the problem is gone.

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Thanks!
Looking at the circuit again, the left 1712 resistor seems to be a pull up resistor for the I/O line.
@ftaka reported that the SIM worked for him even when this pull up remained unconnected.
Though @gehstock reported that without it, his SD card had issues.
See here and the few following posts: http://xdaforums.com/showthread.php?p=35138573

Replacing the pull up resistor with near zero resistance short cut doesn't seem entirely right to me. The current will go high while the I/O line will be at level 'low'.

In the mean time I've tried to convince Vodafone CZ to provide me with their older non-LTE SIM card, which they offered before their switch to new uSIM cards during the last August. But so far it looks like they prefer to lose a customer than to issue the older card.

I'll definitely have to do something, so I guess I'll first try to reduce the pull up resistance.

kabaldan said:

Thanks!
Looking at the circuit again, the left 1712 resistor seems to be a pull up resistor for the I/O line.

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I haven't had any time to check what the resistor actually does, the pull up function looks more than a reasonable guess to me.

BTW we are talking about a real world circuit rather than the perfect theoretical one, and as we know, often the real world is way different than the theory that describes it.

Likely my tin bridge is a way different than a perfect short circuit, the copper lane too, it has it's own resistance and so on, likely the behavior will change because the sim tolerances/different make/different generation.

So I'm still trying to understand what's going on, I believe the value of the resistor is an important variable, maybe an higher value is better for the SIM X, and a lower value is better for the SIM Y.

Too bad the resistor is so tiny and can't be replaced easily w/o risking to destroy something

In the mean time I've tried to convince Vodafone CZ to provide me with their older non-LTE SIM card, which they offered before their switch to new uSIM cards during the last August. But so far it looks like they prefer to lose a customer than to issue the older card.

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I have the "BIS service", here in italy. They are two "twin" SIM with different ICCIDs but with the same phone number, one of the two can be used as master and the second one as slave, with further configurations possible.

Very handy to use the second sim on a different phone/on a gsm car stereo, on a tablet and so on, using the same traffic bundle.

That said while I have replaced the main sim (called SIM ONE) with an LTE + NFC model, the secondary one (called SIM BIS) is available only as good old 128K sim without any LTE support.

Both the sim are working fine on my photon Q, while the older one has the STK that doesn't work on the original Photon 4G.

It's the triumph of the imprecise science, the newest one works fine on an older phone, while the older type has some glitches.

So I perfectly understand your frustration.

For the record Vodafone Italy too doesn't allow the sim downgrade too, if you have a 4G sim you have to stick with it.

Ive modded two of these myself only issue ive incountered on either Q is the handshaking issue IN cm10.2.1 between H+ and 3g (loosing data completely in 3g) otherwise they work perfectly and one of them suffered a fatal dropping accident and replacement digitizer and its still kicking, no sim card errors, perhaps its the wire used in the mod, i used rubber coated in each modd to prevent grounding found that the coated solid wire was too hard to tin and too difficult to prevent from grounding issues inside the phone

Hi,

I did the sim mod and its working well. But the white keyboard foil is damaged. All the keys are working, but the backlight is terrible. If someone has a broken mainboard I gladly buy the foil. I'm living in Hungary. szegi2 at yahoo dot com

Currently I'm working on the removable battery mod for photon q
Droid bionic battery (HW4X/TW4X) works with photon q without any problem.

And finally, after trip to Prague, my mobile moded by corholio arrived.. perfect work and working ok... even after the mess i made to ttrying to do it myself... absolutely recomended no anyone...

One thing i'm experiencing, is that battery doesn't last as much as mi old xperia S... it hardly finish the day with very low use.. is it normal? maybe a time for replacing the batt with a new one?