FP4 randomly crashes and turns off

Hey there,

I have a problem with my FP4. It’s really randomly turning off (blackscreen) and I can’t do anything anymore. First it happened with a few days of time apart, now it’s almost every day. Sometimes multiple times a day. There seems to be no consistency to it. I cannot trace it back to any specific app being used or that it only happens when I’m charging - none of that. I usually take out the battery and gently blow into the contacts because in the beginning I thought it could be a problem there. I’m pretty sure it’s not just the screen blacking out because even if I do nothing to the phone most of the times it eventually restarts again by itself. In some instances I take off the back cover, take out the battery and put it back in and try to restart - it starts booting up but in 1/4 cases when I turn it around to fix the back cover again it turns black again. So it could also just be a loose contact somewhere? But which parts would make the phone completely crash? (I am no expert but I thought if any camera module oder speaker module wouldn’t work the whole phone would still be ok)

I know it might not make a lot of sense to post this here because it’s hardly diagnosable from what I described above. I just thought maybe someone would have had a similar problem or that this is maybe typical/known behaviour and can be traced back to a specific problem or part.

Thanks for reading

Sounds like it to me. In your place I would disassemble the phone, removing all modules. Then clean the contacts with surgical grade alcohol (90° available from chemists / pharmacies) or isopropanol using a cotton bud. Leave to dry at least an hour and then re-assemble.
While it’s important that the contacts be firmly held in place, don’t tighten the screws too much.

Obviously the phone will still be under warranty but the above may save you having to send it back.

For disassembling the phone, follow the iFixit teardown linked below, or follow the replacement guides.

Hey, thanks for your thoughts on the matter. Right now it seems like I was able to fiy the issue. After going through the trouble shooting steps and nothing worked, I dissasembled the phone completely and put it in a bowl of dry rice for approx 12h from thursday to friday . Since Friday morning the phone seems to work properly again and has not shown the issue again. If it reappears I would definitely try to clean it as you said.

I am so sorry to hear that as it has been mentioned on several occasions how bad rice particles might be for your phone.

I am glad the unwanted behaviour stopped but I would indeed strongly recommend cleaning it now before rice particles can do any serious damage.


NOOOOOO not rice !

If your phone is working again it’s more likely just the act of disassembling / re-assembling. I suggested cleaning the contacts while you were about it. As Meaghan says, that is now mandatory if you want to keep your phone for more than a few weeks.

For other readers, please note that using rice is NEVER a good idea, and that the “advertised” solution is not to be recommended.

Hey again, thanks for your advices. I wonder though that kind of damage you mean the rice could produce? I “cleaned” the phoen with pressured air before reassembling so I couldn’t imagine there being any dust like particles left inside. Do you disagree?

Yes. Search for “rice” on the forum and you’ll see. Starch all over the place …
Rice has been suggested in the past because of its absorbent properties, but it’s not a good idea. Much better to clean as I have already suggested. Drying should be done simply by leaving the components in a (slightly warmed if possible) airflow for a sufficient time.

You can help keep a phone dry by putting it in a waterproof pouch with a sachet of silica gel, but it must be dry to begin with, inside and out.

I would be very sceptical how much starch acutally left the rice grain when the general haptics of the phone seemed already completely dry to me. so either there was a very small amount of humidity in the phone that the rice absorbed - in which case I’d argue that no big amount of rice got quelled and released starch + I tried to thoroughly clean it with PA as mentioned before. or in the other case that the reassembling did the trick and it had nothing to do with any form of water being inside the phone - in that case no water would mean no release of starch from the rice. starch itself is also just a powder - in dry conditions it should be easily removable with pressure air treatment, no?

FYI: I dissasembled and cleaned it again just now :+1: