Problems with K850 :(

Hi guys. First of all, I must apologise for my grammar and spelling mistakes, because English is not my native language.
I'm relatively new here, and i have registered on this forum months ago because i needed files for flashing my K850. I'm writting a post for the first time, because i have 2 problems with my phone.

Since i had problems with it's original firmware, i decided to flash it with R1FA037 firmware. And everything went fine. But after a couple of months the touchscreen buttons started to fail. Sometimes they work, sometimes don't, until they stopped working completely. Now, since i thought it might again be a firmware problem, i flashed the above mentioned R1FA037 firmware, and it worked for about 10~15 minutes, and the touchscreen buttons stopped functioning again.
Then i decided to try another firmwares. I have downloaded R1FA035 firmware and flashed it. Everything went right, but when i tried to turn on the phone, it showed only a black screen, and a bit later some artifacts on the screen. Then i tried with R1FA036, same thing but without artifacts. I could hear the shutdown sound when i was turning it off.
Now i'm running on R1FA037, but dunno for how long.

My questions:
Why i can't flash previous firmwares other than R1FA037? I will try with some older firmwares, but i don't think that will change anything.

Why my touchscreen buttons keep failing? Is that software or hardware problem?

Thank you guys in advance. Greetings from Serbia :a014

hey friend,had the same problem with the keys and i can say that it is a hardware problem,i managed it just like you to get them working for some short time when flashing my phone but it didnt hold on long and the keypad died after that..you will have to replace it,it was for me about 15 euros here in bosnia..the second thing is your firmware problem; have you tried the right FS and MAIN fw for R1FA035 and 036? and offcourse the right CUST? well as far as i know you have to use the right things i mentioned together so u can get it to work :) hope u get it fixed dude :)

Hey, didn't know there are Bosnians or any other people from ex YU on this forum :)
Good to know what's the problem with it. Yes i used the right files, at least i think so. But never mind, i flashed R1EA037 and it's working with that firmware, the situation is a bit better with the touchscreen keys, but still they sometimes stop working.
15euros? I thought the price for repair will be a bit higher, if it remains under 20 euros i'll be happy :). I really love this phone (more it's camera than anything else), but i'm not going to spend a lot of money to repair it. I mean, it's not worth it.
Thanks for the info :)

well :D im glad too that there are more people from our region here :) well,when your phone is working well with that FW than leave it..my situation is a bit sticky,cuz my k850 seems to be seriously damaged,i cant get it to charge the battery,but im pretty sure that the battery and the charger are ok..thinking that it could be an erom damage,but no way to repair it for free,and paid services are no help because the payments are nearly imposible from my country..but never mind.. :) im sure that your keypad problem is the same as mine,and to repair it shouldnt take more than 20 euros..the phone is great,i personaly like its design,and offcourse the features like camera etc. but sony ericsson didnt manage it to make the phone pretty stable if you ask me :D they could really take some more time to make it better..hope u get your fixed soon,ill give my best to get mine to work,cause i really love that phone.. :) pozz druze

@domcale keypad that you need is 8 euro in DV(3g company).They have keypad for 6 euro but i would buy one for 8 euro because it is better quality.I don't know where you live but maybe you can get it from DV Novi Sad or DV Belgrade.

I will take it to the nearest place where it can be repaired, unfortunately Novi Sad is too far from the place I live, and so is with Belgrade.
This R1AE037 firmware is too buggy, the phone locks up very frequently, it doesn't do that with R1FA037.
Again, thank you guys, I will tell you what the cost of repair was :)

@KingOfKingz1
It's probably what you think, an EROM problem, but does the red light on the power button flash? If it doesn't flash than the problem could be in the connection between the charger an the phone and its battery. I always look to try the solution for such simple things before you say to yourself that you can't do nothing and that you have to hand it over to someone with more knowledge about these little things :D
Hope it's not the EROM :)
Pozdrav drugovi :P

well the red light doesnt blink like when there is an erom problem,it lights up shortly like it should when the battery is empty and you start to charge..then the keys light up for about 2 seconds and the phone turns off..and it does keep doing the same every time i try to charge it..ill try with a different mainboard,cause i have one at home..ill see what i can do,but i have to fix that problem.. :) well 4 us it should be like: "imposible is nothing" am i right?! :D haha

It looks like i killed mine completely... there are artifacts on the screen, then the screen locks up (phone continues to work, i can take pictures and i hear the shutdown sound, but don't see anything), and the display gets dimmer and dimmer until it gets completely dark. Sometimes the colors get inverted, ie the black colour on the screen gets white and so on.

Looks like the graphics chip have died, but i'm still wondering why that happened? I'm probably record it with my sister's camera and put it on youtube, to show you what's happening to me.

like also happen to my K850, I took a few shoots suddenly the phone hungs... i remove the bat. and put it back again... but the phone is BROD, i flash it and everything go back to normal, except that one left touch key won't function properly, I re-flash again using other FS and other ways that this forum suggest still same problem, so i decided to replace the keypad, then the problem is fix, but several month the phone become BROD again, then I re-flash again, the phone is fix, but the left touch key is bad again, I wonder is these a bug or what... that everytime my phone BROD and when I fix it I have to replace the keypad because its also broken. I already done this 3 times, and already bought 3 keypads for this phone.

the reason behind BROD is that when your keypad is damaged, the phone came to BROD, and not after BROD and vice versa