samsung galaxy s5 bootloop when restarting

[AC Question]

Hi i have a strange fault with a samsung galaxy s5 sm-g900f i bought from ebay. I received the mobile and it was bootlooping for hours and not loading up. I dowloaded a rom from sammobile and successfully flashed the rom and the mobile started up ok. However when i restart the mobile it doesnt always start fully sometimes its ok and then sometimes it loops, it get to the samsung galaxy s5 screen then vibrates and loops again, it never gets to the animated samsung logo and the blue led doesnt come on. when the blue led comes on after the samsung s5 screen then the animated samsung logo appears and then it always boots ok.

Basically ive tried 5 different official roms and it starts to works ok after a new reflash then after a few restarts or power downs and starts it starts to intermittantly bootloop and if i leave it with the battery out overnight and try starting it it doesnt always start and bootloops if i leave it a while in bootloop it may start ok.

I can get into download mode every time but not recovery. I can only get into recovery mode sometimes.

Im pulling my hair out i cant firgure it out, the buttons seem ok when it starts, theres no sticking , the battery seems ok, but someone did say it could be the battery, theres more chances of it working when its warm or hot.

 

[nahoku]

My question to you is why are you holding on to this phone? Return it for a refund... unless you purposely bought this non-working phone.

 

[androidfan999]

Hi, I actually bidded and won a s4 working from the seller for £ 55 but instead he sent me the s5 with the bootloop fault by mistake, the seller is offering to refund me fully but is also happy for me to keep the s5 and hes left it to me. I have a few days to try and fix it otherwise I will be sending it back.

When it loops and I try entering recovery mode it just shows 'Recovery booting' at the top in blue text for a few seconds and then loops again. download recovery works everytime. would this be a hardware fault or dodgy battery???

Im just eager to get this fixed as id have a working s5 for £55, ive fixed many android devices for friends and family and this is the only ones i cant figure out especially when it does eventually boot up and work ok.

 

[nahoku]

There's no telling what specifically could be wrong, but more than likely it's the motherboard. The seller probably knew this and tried to pass this to you so he can just get rid of it for a little cash. Not the first time this has been seen... it happens on ebay and swappa. Good luck trying to get this to work if multiple reflashes won't take. You could go through the additional expense of purchasing a "hopefully working" motherboard, but that's up to you.