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Información de reparación y desmontaje para el iPhone SE de segunda generación, anunciado y lanzado en abril de 2020.

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Please help identify the source of cellular failure

Hey everyone.

I’m in a kind of long-lasting attempt to figure out where the problem is coming from - the one that’s causing “No Service” network status and ongoing “Mobile Data Failed to Update” error, that’s shown on device boot up.

Background

Initially the device started to experience the problem this way: while on, either when i’m using it or just liying on the table - it got itself rebooted occasionally, then after booting up - showed the error I mentioned above. Rebooting it couple of times, but intentionally after this had some chance to get the network back working.

Repairs

Here’s the thing - I tried to get help from 2 repair shops.

1st attempt

The first one addressed the issue to power management controller (if I remember the name of the part correctly), did their attempt to reball it, returned the device and it happened to work fine for a couple of days - then issue showed itself again.

This time - no occasional reboots by device like it was in the very beginning, but anyway the signal loss was triggered by my intentional reboot. I should say that while network was up, no problem with connection quality whatsoever - everything cellular worked just like it should.

So a day after the cellular connectivity came back to life - also triggered by me rebooting the device (it actually was done by me with no hope to get the signal back, but ‘cause of ongoing work with media I use this device for - performed it just to get the clean boot for better performance). Next 4 days the network was up and running with no problems at all, with me avoiding powering off the device just to test if’s in fact connected to cellular failure episodes. So, right untill the next reboot, which happened after those 4 days - as i was expecting - there were no problems with cellular connectivity. So, this time I returned the device back to the repair shop, explaining what I’ve experienced.

After inspecting the problem again, the guys returned the phone back saying that they doubt that they are able to help.

2nd attempt

Another repair shop - I did my best to research and find the one that is experienced with iPhones and cellular-related problems in my area.

These guys, after inspecting the device said that it won’t be an easy job, that there’s a risk to damage the board so they will act carefully and it will take time, so they asked me to be patient.

As they explained to me (a person being not too familiar with micro electronics repairs), there are several points which serve to maintain connection between the modem and the logic board and while examining the device, they couldn’t see one of them and this is what they will try to recreate.

Long story short - the day before I got back to the shop, we had a call during which they confirmed that they finally got the modem powered up, but just by measuring voltage while the device is still teared down. Next, they would have to assemble it back and make sure that everything’s working. Which unfortunately didn’t happen - from their words, the device seemed to have the signal for a minute, then lost it again with the same “Mobile Data Failed to Update” error.

After-repairs

So as I rely on this device for my media creation related work, I temporarily use it in its current state of iPod Touch, while trying to figure out the next move to get it fixed.

What’s important - network happened to come alive even after the second repairs - and just like previously I decided to do my best avoiding powering off the device to see if it would loose its cellular connectivity in that case and if there will be any problems with signal strength, etc. Guys, I find it extremely strange that once booted to the state when it properly recognises modem - it just works perfectly fine and there is really no chance to loose the signal excluding 1 particular case - if the device is powered off. So this time it even survived 1 more reboot (due to battery drain, which I didn’t noticed on time) - and then gone dead on the 2nd one again . And this is the state in which it exists now.

So the main conclusion of my experience is that:

• the signal loss always happens after a reboot and no other way.

• once it occasionally boots up recognising SIM and network - no chance that it will loose its connectivity unless it’s powered off - either intentionally or not (such as battery drain).

———

Does anyone have any clue what may cause this problem with this particular power-depending simptoms? Any kind of “brainstorming” from you will help as well - at least for the purposes of finding the right specialist rather than searching for the one that’s familiar with broad term of “cellular-related iPhone problems” - maybe I should instead specify my search somehow?

!

By the way - both repair shops confirmed that the modem itself (Intel is installed on this one) is fine .

———

I know that the text is freaking long, and apologize for that, but I just have no idea how to may it shorter, tried my best.

Many thanks in advance for any feedback!

Contestado! Ver respuesta Yo también tengo este problema

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From what you have described it is more than likely the fault is in the logic board itself. You have had two repair shops look at it. It sounds like the first repair shop thought the problem was with the baseband PMU. The second shop would have seen that the IC has been worked on and would have checked it again than moved onto the baseband CPU.

Since this problem is intermittent there could be two causes. Either there is a pad under the baseband CPU or sim housing that has become cracked and oxidised or the other reason which I suspect would be a faulty trace in the logic board. The SE has eight layers of board so different circuits are on different layers. When a trace is broken or a pad is cracked it can become intermittent by putting pressure on the board or a change of temperature. So let’s say the first repair shop thought it was the baseband PMU and changed it, the heat put on the logic board usually causes the contact of the faulty trace to reconnect. When the board cools down or flexes the trace may separate again.

It was a similar thing with the second repair shop. They would have removed the logic board and may have put some heat or even just tested it and it might have tested fine but when they installed it back into the housing the problem was still there. This points to a faulty trace. I have learnt from experience and do not except these types of repairs because of this reason.

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2 comentarios:

Hey, really pleased to see a reply that’s backed up with practical experience, appreciate taking time to post a detailed feedback.

I’m still trying to figure out the optimal perspective in regards of this this device’s destiny. So in worst case scenario i’m having faulty logic board. How would you rate the option to replace the whole logic board as a way to fix the device in terms of chances to succeed? As I understand it would result in having different IMEI as well as home button replacement.

Sounds like not that much of a problem in terms of complexity of the whole operation yet expectedly I’m having concerns whether it’s practically possible to have a positive experience buying a logic board as a spare part.

Browsing through web I can see that the price varies depending on the source of the part but anyway economically it seems to be more practical than buying a new device. In case it actually can be considered as a relatively good option.

Thanks in advance for your advice, Chris.

Peace!

- de

@lurch_space It is risky purchasing a logic board and home button. You have to consider the reason why they are selling the device for a start. Had the device been impacted by something? Causing the screen to smash and housing dented or bent? If so you could end up with the same problem you are facing now. You might get lucky and it is an easy replacement to swap the logic board and home button.

- de

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