yashsingh1/xdaforums huggingface dataset:
[Motorola Photon Q 4G LTE] mionica:
My reasoning is as follows (the numbers are just hypotetical): if a standard SIM requires a stable supply of, say, 1.25V, guaranteed to up 500mA, but Sprint's SIM IC supplier guarantees no more than 350mA will be drawn by their chip, I - as an engineer - would probably design the SIM power supply to provide 400mA at 1.27V. In this hypotetical scenario, if a SIM would actually draw 500mA, you'd end up with the voltage dropping to 1.18V or similar - possibly engaging the SIM's reset circuitry, and probably for a shorter time than a SIM reset would actually require (leading to logic states that happen not to be on the books).

Now, SIMs' dies (the silicon thing that does the magic, embedded in the plastic below the SIM contacts) come from different manufacturers - though it's likely that one mobile company would choose one supplier and stick with that. And their exact power requirement will most likely differ - but as long as all of them obey the standard (regardless of what it says), it's fine...

...unless the Motorola people optimized for something more drastic than what the standard mandates. After all, this phone isn't supposed to work with 3rd party SIMs.

Also, one should note that the drawn current is not a constant: it increases when the SIM is busy, gets rather low when it isn't. That would mean that it would be particularly unstable when the phone actually needs to run the programs on the SIM - say, when changing cells? :)

And the fix is simple: find a testpoint, an IC pin or something that supplies the same voltage as the SIM receives, but be on a different power subsystem on the board, then shorten that to the SIM's supply. This way, the SIM would only draw half as much current from each of the sources. So as long as there's one point on the board with the right voltage, serving a subsystem that's over-provisioned for power, we should be good.
[Motorola Photon Q 4G LTE] CornholioGSM:
.....from where have you info about original sprint sim chip?
[Motorola Photon Q 4G LTE] mionica:
I don't have that info, sorry - that was a purely hypotethical case (I just picked some seemingly sensible values for voltage, currents and everything) I used to

illustrate the concept

- that's all. I don't know the first thing about SIMs.

That aside, I recongnized a failure pattern I've seen quite a few times - and thought I'd point this out. It was an analysis/suggestion based on my industrial experience - feel free to ignore it if it sounds crazy. It's based on my share of debugging embedded board prototypes.
[Motorola Photon Q 4G LTE] Skrilax_CZ:
Actually that theory makes sense (except the currents, which are probably in tens of miliampers). There is a peak in the current upon switching from 2G -> 3G (or in general, when registering to a site, and 3G requires more power obviously, because more tasks / better cryptography). I'll take a look on the GPIO setup in the kernel.

NO!!!!!!! You must never connect two voltage sources in parallel (except for specialized circuit)!
[Motorola Photon Q 4G LTE] mionica:
Hmmmm. Why? Any ASIC, including a SIM's die, is an active component, and will draw the current it needs from a voltage source. Now, if you had a current source instead, I'd agree; I'd also agree if we were talking about a passive component; furthermore, I'd agree if the board had multiple ground planes (but I haven't seen any digital board with this, to date). I also couldn't agree more, if the two sources provided different voltages.

But neither of these seem to be the case.

I'm not sure that should matter? A few pages above there were some fellows complaining how the SIM from a company worked, and the one from Vodafone didn't - in the same phone. My argument was not that the radio drew too much power (if that were the case, the wifi trick absolutely shouldn't work) - but rather, that some of the SIMs would (hence my add-another-source-of-the-same-voltage suggestion).
[Motorola Photon Q 4G LTE] Skrilax_CZ:
You can't connect power voltages in parallel because they would start "fighting" each other (they are not ideal sources and they are in fact regulators converting from one voltage to another, so even with very similar voltage). Same goes for current sources - you can't connect them in series.

Yes I got that some SIMs could drain more power, but that can be reconfigured. If enabling Wi-Fi helps depends on how the current regulation is actually wired. This has to be examined in kernel and compared with RAZR HD or other similar phone.

There is also another possibility that came to my mind - the inductive character of the wire connected to the SIM could cause local power shortage if there is sudden change in power drain (long enough to drive it crazy). It would also fit to when someone reported hardwiring the SIM helped, which would actually help because he shortened the wires in doing so.
[Motorola Photon Q 4G LTE] Al936:
No, the issue is present with sim card soldered to main board without sim card slot. At least my Q does not have sim card slot and the issue is here.

Also I would like to report that wifi trick helped me a lot, but it does not close the issue for 100% - after several "good" days, I lost GSM and GPS today :(

The other strange thing, at least for me, why GPS signal depends on GSM. As I can see if GSM lost, GPS also died...
[Motorola Photon Q 4G LTE] kabaldan:
A small correction:

I wasn't complaining. I mainly wanted to let users know that one of the main developers for xt897 is now able to reproduce the issue ;) .

And I'm glad that there's this brainstorming happening now.

To update my conditions: I never turn off wifi on my phone. The SIM failure is now happening +/- once in 24h.
[Motorola Photon Q 4G LTE] mionica:
Makes sense. I don't have a clue how Qualcomm does things, but on the things I'm toying with, a GPIO definitely has configurable everything - direction, voltage level (when output, 2v5/3v3), pull resistors and current (in my case, 2/4/6/8mA). What I don't know is, whether the SIM is attached to GPIOs - or some other interface (USART? SPI? no idea). Actually, if you have any docs concerning that, PM me pls.

EDIT: turns out it's UART, except you toggle the I/O pin between RX and TX. Hopefully then, it's a GPIO. Keep us posted.
[Motorola Photon Q 4G LTE] kabaldan:
There's this document available (not sure how much the moto implementation differs):

http://d-h.st/xJ9

If anyone has this package, I'm deeply interested, thanks :) :

http://xdaforums.com/showpost.php?p=37542393&postcount=53
[Motorola Photon Q 4G LTE] Skrilax_CZ:
GPIO is used for power control. Maybe the reason why GPS drops with GSM simply is (as reported), that they both are connected to same source with same current limit.

Looks like we should examine our devtree on the phones to see the actual configuration along with kernel sources.
[Motorola Photon Q 4G LTE] mionica:
Hmmm. Things to note: 1) RST/CLK are filtered (33pF capacitors); 2) I/O isn't (connected directly to UIMx_DATA_CONN); 3) revC added a pullup resistor on I/O.

3) is my WTF; it'd mean that either some (probably recent) SIMs have an open-drain I/O line, or that (more likely) the thing was always open-drain, and pre-rev.C sw enabled an internal pull-up in the PM8921.

There's also the possibility that the PM8921 internal pullups for lines MPP_02/MPP_04 proved too weak for what some SIMs required, leading to only introducing an external 10k pullup in revC.

Cornholio: could you check whether you can measure a 10K resistor between SIM's VCC and I/O?

Slightly higher value capacitors could probably compensate, if this were the case...

Feck it. I'll just order one next week, ship it to cornholio for the mod, and proclaim it my lab rat when it gets back. I hope my SIM doesn't work properly with it :D
[Motorola Photon Q 4G LTE] Skrilax_CZ:
For the wire impedance:

Those capacitors weren't there for this, they were for electro-magnetic compatibility, and can be omitted with the SIM mod. The problem in the wiring would be length of the wire, and yes, blocking capacitor is the solution, but it has to be close to the simcard and there is no space for it. But this is more theoretical, it matches with the statements:

- SIM card losing power when changing 2G -> 3G

- hardwiring SIM card helped

It mismatches here:

- when GSM looses signal, so does GPS (may be unrelated), and enabling Wi-Fi helps (and Al936 has hardwired simcard)

- there is a Vid in OP showing the simcard connector being completely outside the phone

So it doesn't feel completely right.
[Motorola Photon Q 4G LTE] kabaldan:
Regarding GPS: If you boot without SIM, GPS won't work either.

On the other hand, GPS works fine in Airplane mode (when there's an active SIM), so GPS doesn't directly depend on GSM signal.

EDIT: Now my SIM failed again (I've disabled WIFI for now to see if the errors will be more frequent) and GPS continues to work here...
[Motorola Photon Q 4G LTE] CornholioGSM:
haya kabaldan...i need your phone for test new wires and maybe new slot...contact me on PM :)
[Motorola Photon Q 4G LTE] schmandroid:
Hey Cornholio - wonder if the wire gauge is causing issues?

I've got heavier gauge wire in the one I modded. Haven't had any issues with it.

Wire that is too thin may have volt-drop issues, which may lead to sim rego/maintenance trouble. Anyone have any actual measurements of current requirements of different sim cards? Can determine minimum gauge if the max amps is identified.
[Motorola Photon Q 4G LTE] CornholioGSM:
it is not 100% sure, but i will test it with 0,3mm wire
[Motorola Photon Q 4G LTE] x86Daddy:
AT&T in the USA!

This guy right here is full of win:

I had to actually run through this twice, possibly due to this:

http://xdaforums.com/showpost.php?p=38837493&postcount=8

I went ahead and let it sit for a minute before rebooting the phone, and I used the phone itself to reboot, rather than RadioComm's restart button.

After modding NV Item 8322 that second time and rebooting, my freshly SIM slot modded Photon Q just made a phone call on AT&T in the USA. Am I first? :D
[Motorola Photon Q 4G LTE] CornholioGSM:
....uuuuu good work :) so all works fine withouts problems?
[Motorola Photon Q 4G LTE] x86Daddy:
So far, all works as well as I'd hoped! I made phone calls, used the AT&T "wap.cingular" APN to use data, browse the web, and run speed tests (same results as my other HSDPA phone). I was able to run the mobile wifi hotspot and share the connection, all without problems. Sharing over Bluetooth PAN didn't seem to work, but most Android phones I've had have failed at that, and I'm currently running the Sprint/Motorola 4.1.2 ROM... will try it again on another ROM soon.

Thanks so much for performing and documenting the original mod here!
[Motorola Photon Q 4G LTE] CornholioGSM:
okay...i go put info to first page :)
[Motorola Photon Q 4G LTE] hans_dampf88:
hey guys.

sim mod is working quite well. I did the mod myself and have a microsim from farnell inside.

I experience some issues though:

battery life is more than horrible. I used ot today and with 3g on and not using it at all it lasted only 10hours with screen off in my pocket.

(for comparison: a friend has a razr and had 98% when I was having 20% and we started fully charged into the day ...)

also the device gets quite hot while charging and the screen isnt as sensitive as when I start fresh with a cold phone.

Those 2 issues are real bummers ... did I just have bad luck with buying this phone and battery is crap?

What are the options? :)
[Motorola Photon Q 4G LTE] schmandroid:
Could there be any chance that something like this will allow MMS from stock ROM? I add APN's, but not sure what settings are limiting sending. Changed server under DATA menu also.
[Motorola Photon Q 4G LTE] every1nosme:
Any chance of using this method on the droid 4?
[Motorola Photon Q 4G LTE] mrvek:
I doubt that Droid 3/4 have NV items.
[Motorola Photon Q 4G LTE] Hendrik212:
Hej Cornholio,

it's very strange...after I received the phone modded by you, I had a stable simcard connection from 12th to 16th August (Vodafone DE) in Munich.

Switching from 2G to 3G happened regularly as GSM signal is sometimes weak or even non-existent at the place where I work...but it always reconnected without problems.

Then at the weekend I made a trip within Germany and stayed at a village with only average network coverage. There the problem of loosing signal and then simcard connection happened for the first time.

When I returned to Munich it happened once on the highway, simcard error and lost gps signal.

I'm now back in Munich but it happened again today when I arrived at work and drove into the garage without network coverage. After leaving the garage the signal couldn't be restored and connection to the simcard was lost.

I don't understand what happened. Let me know if you need any logs or other information.
[Motorola Photon Q 4G LTE] m_o_t_m:
Hello mates, my name is Heinrich and im from Germany.

This thread is really great.

I have been searching for a qwertz/y phone for a long time and now it seems to come true. I have been following this thread for a few weeks now and finally ordered two Photons in the USA.

Opening was no problem for me. To remove the metal cover i use a gas soldering iron with a hot air funktion. Reconsidering i think i didnt reach melting temperature because i was afraid to destroy any components.

Later on i decided to heat with full power and nothing was damaged. With the full power technique i was able to remove the metal cover and the chip.

Although i think i got some soldering skills i have to admit it was not my best work. Also i lost tree resistors when i tried to grab the chip with the nipper. I have never seen such tiny things before.

I managed to short circuit 2 of the 3 missing resistors with a soldering blob. It was pretty tough work considering it is kinda impossible without a +50x magnifying glass.

Over time i lost my concentration and was not able to short circuit the third one. Even worse i broke the contacts on the board. It was really frustrating.

Afterwards i came to the conclusion that you could just use silver conductive paint instead of a solder blob to short circuit the missing resistors. I think it would be much easier.

Now my problem:

Is there a way to short circuit the missing resistor at other connection points?

Picture down below....

.....QWERTY phones for everybody..... ;)
[Motorola Photon Q 4G LTE] x86Daddy:
Although this is a little late for anyone who has already lost resistors, I'll share what I did to prevent that: I put down some strips of kapton / polyimide tape... the high-temperature yellow tape, over those components adjacent to the chip. I followed this by a few layers of tin foil and more tape, with a cut-out right over the chip only. I used the pencil torch method to heat the chip and remove it, and the flame definitely burned some foil and melted the tape a bit, but after I removed the chip, the surrounding area was perfectly clean and intact... not even discoloration. I highly recommend polyimide tape and foil.
[Motorola Photon Q 4G LTE] jhgotin119:
Mod Service

Is there anyone doing this mod service in the USA..if so please let me know what your successes have been and how much it would run me to have this done by someone with some experience. Also would this work with any sim card on a phone with a bad esn. Wanna buy a bad esn phone from ebay but just wanna confirm that it will work with this sim card mod

Thanks
[Motorola Photon Q 4G LTE] w0ng88:
I second this, especially when for soldering wires to the solder pads. Just make sure excess solder *if there are* does not flow underneath the tape where it did not stick properly to the board, as it may led to short circuits (metal/solder dust, fray wires etc as well). I believe short circuit is a more prominent problems when you lose yr caps as the solder pads are exposed, so take care and make sure nothing shorts the solder pads for those missing capacitors.
[Motorola Photon Q 4G LTE] Paitor:
Yeah, is there better batteries as replacement or kernel/software update that can help?
[Motorola Photon Q 4G LTE] Sperion:
Is there maybe someone in the netherlands that provides this service?
[Motorola Photon Q 4G LTE] arrrghhh:
Czech Republic is pretty close... A lot closer than the USA to CZ, that's for sure :good:
[Motorola Photon Q 4G LTE] milannalim:
Does anyone have any experience with carriers from or connectivity in Slovenia (has a modded phone here or was traveling to/across Slovenia)?
[Motorola Photon Q 4G LTE] mrvek:
In Croatia it is working fine, currently on Tele2 HR, so it should work fine for you as well. Occasional signal loss might be possible because of loose contacts or unknown reason (has been discussed in this thread recently).

Photon Q:

CDMA: 800, 1900 MHz

GSM: 850, 900, 1800, 1900 MHz

UMTS: 850, 1900, 2100 MHz

LTE: 1900 MHz

So LTE will probably remain inaccessible because LTE in slovenia should use 1800 freq (in cro additional 2600 should be available).
[Motorola Photon Q 4G LTE] lightning3:
good point, moreover contact with CornholioGSM and meet personally with Him, weekend in prague sounds nice ;)
[Motorola Photon Q 4G LTE] Skrilax_CZ:
I don't think he is at work on the weekend :P
[Motorola Photon Q 4G LTE] CornholioGSM:
weekend...nooooo i am from monday to friday day by day in my work up to midnight :(

i need some free time :)
[Motorola Photon Q 4G LTE] sarnosos:
hello, I want to acknowledge the work of CornholioGSM, made the mod chip into my motorola q phonton, and everything worked perfectly.

Gsm: works

Internet: Works

And everything else.

Good job. :laugh::good::fingers-crossed:
[Motorola Photon Q 4G LTE] Sperion:
haha sounds nice, but it is definitely more expensive then just sending the phone to him :P
[Motorola Photon Q 4G LTE] Skrilax_CZ:
Yes, he could also taste what's the real beer here in Prague :)
[Motorola Photon Q 4G LTE] chinanb:
amazing！but i can't do this alone.my dad won't help me:crying:
[Motorola Photon Q 4G LTE] lightning3:
no :) price for polskibus.com is between 30 and 90 zl. Cheapest package with insurance - 200 zl in both ways. (exchange rates -> google)

Maybe we learned different Mathematics, but it is cheaper and safer :).

Additionally , like [MENTION=2228410]Skrilax_CZ[/MENTION] said, you cannot compare Czech Beer taste with those at Poland

And weekend, i mean from Thursday to Monday :)
[Motorola Photon Q 4G LTE] tuxor1337:
Seems like you are lucky when starting from Poland. When starting from Germany it's more like 90 Euro for a one way ticket to Prague, depending on where exactly you come from (you might have to take the train to the next bus station etc.). The DHL package is 15 Euro (incl. insurance up to 500 Euro) from Germany to the Czech Republic.
[Motorola Photon Q 4G LTE] Sperion:
and thats about the same from the netherlands :P
[Motorola Photon Q 4G LTE] tuxor1337:
Do you mean netherlands is the same as poland? Which bus company do you have in mind by that? I can only find this: http://czech-transport.com/index.php?id=5651
[Motorola Photon Q 4G LTE] Sperion:
no the same as germany, if i go there myself its about 90euro + stay, if i ship the phone there it depents on wich company i use but it starts from about 15euro
[Motorola Photon Q 4G LTE] Al936:
10 days ago I decided to set "Use only 2G networks" while navigation app is running. Since that day no GSM and GPS signal lost at all. I am still on CM 10.1 (4.2.2) latest build (21 Aug).
[Motorola Photon Q 4G LTE] Skrilax_CZ:
This simply could be bad BP firmware by Moto, thinking about it. 3G was having problems with ICS firmwares (losing data connection and to get data back you'd have to restart the radio).
[Motorola Photon Q 4G LTE] comstyle:
is there a fix for the "only 3G icon" issue on stock?
[Motorola Photon Q 4G LTE] CornholioGSM:
Massimo Grandesso - please contact me on PM !!! On package and phone is not your xda nick.

Thanks :)
[Motorola Photon Q 4G LTE] redsrule2500:
OK since we have confirmation of this working on AT&T I think I'm ready to make the jump.

Now to do it myself or contract out the labor....:silly:
[Motorola Photon Q 4G LTE] tobby88:
Hey Cornholio.

Your PM-inbox is full. Can't reply to your message... Can you please delete a few messages? :) Thanks
[Motorola Photon Q 4G LTE] CornholioGSM:
deleted :) sry
[Motorola Photon Q 4G LTE] uniqdom:
Hi. My brother have done the mod to my cellphone, but by accident, he removed two resistor and a capacitor. He figured out and resoldered them.

I have reduced the size of the SIM card, soldered it, and flashed GSM version cm-10.1.3-RC1-xt897 (relese date: 2013-08-28) downloaded directly from cyanogenmod's site.

When I turn on the phone, there is no signal at all

Assuming that the mod went ok, should it work right of the box once it was flashed?

Under Settings/ Wireless & Networks /More/Mobile Networks, which options should I select for Network Mode, System select, CDMA subscription?

Sim is working as I have desoldered it and tested in another phone.

Help is appreciated
[Motorola Photon Q 4G LTE] j_rivers:
Using this great mod with my old GSM number . Everything's fine with CM10.2 .
[Motorola Photon Q 4G LTE] arrrghhh:
I would make sure everything works in stock ROM before flashing CM.

But, with that said... it sounds like your network mode is set to CDMA despite downloading the GSM build. Check which mode your phone is in. *#*#INFO#*#* in the Phone app.
[Motorola Photon Q 4G LTE] x86Daddy:
I found I couldn't make the selection of network type from Cyanogenmod's menu (using a 10.2 nightly). But I found the solution:

You must use the hidden menu by dialing *#*#4636#*#* and then selecting the network type in the middle of the screen. The Settings-->Mobile networks section doesn't do it, but the dialed menu does. A reboot was needed to see the APN settings.

Before finding the solution, I was able to get it working without the secret menu on the original Sprint ROM, only after de-blocking US carriers. If you're in the US, you'll have to do that too... one of my previous posts in this thread points the way.
[Motorola Photon Q 4G LTE] agazza:
Hey, guys, I shipped my phone today and i forgot to turn it off and turn off my alarm clock, do you think the postoffice will get nervous? :D

Skickat från min HTC Vision via Tapatalk 2
[Motorola Photon Q 4G LTE] CornholioGSM:
heheh...hard to say :)

was the package insured?
[Motorola Photon Q 4G LTE] agazza:
Yes i think so, something thats called recommended letter in sweden, need to google it later

Skickat från min HTC Vision via Tapatalk 2
[Motorola Photon Q 4G LTE] tuxor1337:
I have some further questions concerning the sim mod with sim card holder: http://img803.imageshack.us/img803/8717/img20130103231544673.jpg (pic by CornholioGSM).

Is it correct, that you are using a Samsung Galaxy S3 sim tray for this mod? Like this one: http://www.ebay.de/itm/Neu-Original...zer_Ersatzteile_Werkzeuge&hash=item3cd4305d4c

So you buy those combined sim tray/sd card holder. How do you detach the sim tray? Hot air?

After that, how do you attach the sim tray to the Photon Q's board? Do you solder it to the board or do you glue it anyhow?

It looks like you are removing the gray soft foam on top of the board and you remove the metal cover for the IC next to the HDMI port. Isn't that risky?

Another more general question: The battery is glued to the board, is that right? How do you safely remove the battery then and avoid any damage to the underlying parts?
[Motorola Photon Q 4G LTE] CornholioGSM:
yessss...you can use i9300 slot and you can detach it with hotair from another side.

then is slot frame soldered to mainboard ground...glue is not needed...but what is needed is prehead mobo to approx 200C.

remove cover near hdmi is needed because s3 slot is large...then is needed to have approx 0,5mm or less space between slot back side and capacitors.

battery is glued with doubleside tape....unscrew it and then detach from marked side.

...all is risky, but if you have good tool and nerves...then it can be simple :)
[Motorola Photon Q 4G LTE] CoDoJoTyFlow:
what do you recommend screwdrivers, I bought a set and proved to be a horrible **** :mad:
[Motorola Photon Q 4G LTE] arrrghhh:
This is the kit I got.

http://www.ifixit.com/Tools/54-Bit-Driver-Kit/IF145-022

Love ifixit.com... :)