LG touch sensitive buttons dont work - Hardware Hacking General

Hello everyone
I have this problem with my phone which is a LG GW620 it has touch sensitive home and back buttons and i recently had to replace the flex cable of this device becouse i broke it. The original flex cable had these foams glued like this:
deltamobile.lv/published/publicdata/DELTA1DELTA/attachments/SC/products_pictures/SLP_553_l.jpg
and the one i bought did not have them:
bridgat.com/files/LG_GW620_Flex_Cable.jpg
so now i need your help on what i should do with thease to make the touch sensitive buttons work again becouse without thease foams the buttons dont work.
Sorry for my bad English i hope you will understand what im trying to say here
EDIT: I attached the files with marked areas of touch sensitive buttons and where thease foams are.

Could you mark these foams on photos?
If you mean regular rubbers used to keep things in phone on place - I'd take old ones from old flex and stick them to the new flex.

Yes, what Rebellos said.
The flex circuit board just has the contacts.
The rubber button has a carbon pad on the inside that shorts the contacts.

Renate NST said:
Yes, what Rebellos said.
The flex circuit board just has the contacts.
The rubber button has a carbon pad on the inside that shorts the contacts.
Click to expand...
Click to collapse
ok well the flex cable came with those carbonpads so how do i atach the foam to those carbon pads?

Sorry, I don't know what you mean by "foam" vs. the rubber button.
Do you have a more detailed photo?
You should have enough pieces from the old setup.
Can't you figure out how to merge the old and the new?

Renate NST said:
Sorry, I don't know what you mean by "foam" vs. the rubber button.
Do you have a more detailed photo?
You should have enough pieces from the old setup.
Can't you figure out how to merge the old and the new?
Click to expand...
Click to collapse
there is no button on the phone its touch sensitive mayebey it detects heat or something but with the new flex cable it doesnt do that any more.

Related

Fun times repairing my G1

Okay, so I had this G1 for about a month now, works fine, rooting was a blast, but I wanted to get rid of the cracked digitizer glass. So the part comes in the mail... I read and followed the take-apart tutorials to the letter, install it, put it back together, and what's this???
The screen is dark with no display, I slide out the keyboard and I get a display but no back-lighting. I wait for the thing to get to the home screen and I am not getting any touch-screen action. Any ideas? It is safe to assume the digitizer may be dead but what's the deal with the darkness?
Prior to installing the screen I had the back-light issues and I thought "maybe one of the flex cables are loose" but now I am dead in the water. Any info anyone would have about this would be helpful
Thanks
Dr.Gonz0 said:
I thought "maybe one of the flex cables are loose" but now I am dead in the water.
Click to expand...
Click to collapse
That sounds like the right thought. Clearly, something isn't connected properly.
As i see, there are three variants (from good to bad):
1.) You`ve connected some cable badly, or, for example, you`ve didn`t put down the black blocking panel on some of connectors where it is. As for me, i`ve additionally put some scotch upon any connector i was attaching - it works.
2.) Some cable went bad due to inaccurate handling. When i was doing the same thing (replacing G1 digitizer) - it was stated in manual, tha flex cables, especialy black ones, connecting mainboard with LCD&touch block - can be easily torn. You should examine then carefully - electrical tester would be a nice idea.
3.) You`ve spoiled some chip on the board with static electricity on your fingers. It is really rare - but really bad variant.
Hehe turns out that the flex cable was already fried before working on it, thanks to a great friend I received a new flex cable and was incredibly surgical putting all those cables back in, but I did it. Back up and running @ 100% muahahaha!
So how do I cook for this device?

[Q] Replace buttons without removing main board? Or change wake button?

Is there any way to get to the buttons on the front without having to remove the main board? I just broke my cable to the buttons and I am planning on replacing it soon.
EDIT: Is there any app that will let me remap the key that is used to wake up my phone? I want to be able to use the phone while I wait for the flex cable to show up. I can turn my phone on by plugging it in because it is on MAGLDR.
No, you will have to completely disassemble the phone, including the lcd/digitizer assembly from the middle chassis to access the buttons flex.
Maybe a stupid question that also refers to this but I got conned by a guy whom I bought a HD2 from. Also the cable to the buttons is broken, as so many other things.
Does your touchscreen still react when that cable is not attached?
Yeah the touchscreen still reacts without the buttons flex cable attached, done it myself a bunch of times, so 100% confirmed
huggs said:
Yeah the touchscreen still reacts without the buttons flex cable attached, done it myself a bunch of times, so 100% confirmed
Click to expand...
Click to collapse
Ok thx for confirmation. This guy conned me with a 'perfect hd2' broken camera glass, broken flex cables all around, a broken digitizer, .... well nothing worth then
e334 said:
No, you will have to completely disassemble the phone, including the lcd/digitizer assembly from the middle chassis to access the buttons flex.
Click to expand...
Click to collapse
Darn it. Do I also have to remove the main board from the chassis too or is there any way to remove the screen and digitizer assembly from the chassis without removing the main board?
You do not have to remove the entire LCD/digitizer assembly, you just need to pry enough space between the bottom of the digitizer and the plastic frame to remove/replace the buttons. I've done it to three phones. It may be easier in the end to remove the entire thing, because it can be difficult to get the part that you pry up to adhere back together though. This phone is a major pain in the ass to work on beyond the motherboard area.
brandogg said:
You do not have to remove the entire LCD/digitizer assembly, you just need to pry enough space between the bottom of the digitizer and the plastic frame to remove/replace the buttons. I've done it to three phones.
Click to expand...
Click to collapse
Hmm. Would heating it up a little bit make it easier to pry apart then? I tried it a bit after I realized that I broke the cable, but my device seemed to be really stiff.
And if I do remove the screen, would I need anything special to put the display back on?
Yes, you have to heat it up or you will probably destroy the phone. The best thing you can do is get it very hot (not hot enough to melt the plastic button strip) and try to get the adhesive to stay completely on the frame, then reheat it again right before you put it back together. I repair phones (and game consoles) for a living, and heating the adhesive (right) before assembly is the best piece of advice I can give anyone on just about any phone. Most of the time you don't even have to replace the adhesive if you do it this way.
brandogg said:
Yes, you have to heat it up or you will probably destroy the phone. The best thing you can do is get it very hot (not hot enough to melt the plastic button strip) and try to get the adhesive to stay completely on the frame, then reheat it again right before you put it back together. I repair phones (and game consoles) for a living, and heating the adhesive (right) before assembly is the best piece of advice I can give anyone on just about any phone. Most of the time you don't even have to replace the adhesive if you do it this way.
Click to expand...
Click to collapse
Alrighty. Thanks for your help!

Cuted flex cable for the buttons

Hello,
I recently changed the LCD and Digitizer screen of my HD2, but while disassembling it I half cut the flex cable for the buttons, while trying to take it out. It's not completely cut, its about 1 mm cut, but non of the buttons are working. Is there a way to fix that without replacing it, or i have to replace it and is there different type of buttons cables for the EU and US versions, and will this work http://www.ebay.com/itm/New-Keypad-...887?pt=LH_DefaultDomain_0&hash=item43af09e827
Thank you!
Not so good news
LexHammer said:
Hello,
I recently changed the LCD and Digitizer screen of my HD2, but while disassembling it I half cut the flex cable for the buttons, while trying to take it out. It's not completely cut, its about 1 mm cut, but non of the buttons are working. Is there a way to fix that without replacing it, or i have to replace it and is there different type of buttons cables for the EU and US versions, and will this work http://www.ebay.com/itm/New-Keypad-...887?pt=LH_DefaultDomain_0&hash=item43af09e827
Thank you!
Click to expand...
Click to collapse
You have no other choice than replacing it...
There are no differences for keypad flex between EU/US version.
You *could* scratch the enamel and reveal the tracings underneath, and then bridge the gap with solder, and then wrap it with thermal tape or similar..
I have never had that happen to me during all the times I had to disassemble my hd2s to replace the digitizer but this is what I would have done.
jianC said:
You *could* scratch the enamel and reveal the tracings underneath, and then bridge the gap with solder, and then wrap it with thermal tape or similar..
Click to expand...
Click to collapse
Yeah, you could do this, but then you should prepair yourself to disassemble your device sooner than you've been expected!
In other words I wouldn't recommend this to someone who doesn't disassemble his hd2 every month(even week)!

Hit some problems during screen replacement

Just bought a new screen for a cracked hd2 and hit some problems. Firstly, its a uk hd2, so it was a solder connection, i bought the screen + digi from ebay and noticed it was a ribbon connection (not sure if that will make a difference). When undoing these plastic clips
http://imgur.com/Faiyig3
Both broke. They were so brittle, has anybody seen/heard of a way to fix this? I put it all back together and the screen does come on, but touch doesnt work.
Can anybody tell me what these cables do? Is one for touch, what about the other?
Gutted about my hd2, its been going so well all these years...is it fixable?
Not good :-/
those 2 clips: one is the flex ribbon connector & other is the LCD ribbon connector.
The ribbon from LCD also is feed for digitizer.
Not sure if the locking arms are replaceable by themselves ! will look at an old mainboard & see.
you may get some function by bending a very light V in the ribbon so point of v is ribbon contact face & thus pushes tighter in socket promoting better contact.
putting a bit of tape on back may help too! be careful though as actual socket is very fragile too ...
Mister B said:
Not good :-/
those 2 clips: one is the flex ribbon connector & other is the LCD ribbon connector.
The ribbon from LCD also is feed for digitizer.
Not sure if the locking arms are replaceable by themselves ! will look at an old mainboard & see.
you may get some function by bending a very light V in the ribbon so point of v is ribbon contact face & thus pushes tighter in socket promoting better contact.
putting a bit of tape on back may help too! be careful though as actual socket is very fragile too ...
Click to expand...
Click to collapse
Tell me about it, thanks for explaining what the ribbon connectors do...I couldn't understand why the screen would turn on if the connector was broke. That's a good idea about slightly bending the cable, I will try that tomorrow afternoon. If i could swap them out, that would be awesome.
Thanks for answering, I appreciate you talking time to help a fellow hd2 fan!
Have made none working digitizer work via creating very light v shape bend in middle of contact area (bending across width of cable)
Do be gentle though ... not sure how successful it will be without clamp though :-/
fracmo2000 said:
Just bought a new screen for a cracked hd2 and hit some problems. Firstly, its a uk hd2, so it was a solder connection, i bought the screen + digi from ebay and noticed it was a ribbon connection (not sure if that will make a difference). When undoing these plastic clips
http://imgur.com/Faiyig3
Both broke. They were so brittle, has anybody seen/heard of a way to fix this? I put it all back together and the screen does come on, but touch doesnt work.
Can anybody tell me what these cables do? Is one for touch, what about the other?
Gutted about my hd2, its been going so well all these years...is it fixable?
Click to expand...
Click to collapse
how did they break? i'm going to attempt this myself soon and would appreciate any advice on getting the clips open safely.

G2 unresponsive screen after replacing charging flex cable

Hello
I can't charge my LG G2 D802, so I ordered a charging flex cablefrom ebay.
After replaced, the phone charges well, but the screen is almost unresponsive.
And it's very interesting, because if I replace to the old one, everything is the same, almost unresponsive screen, not like before disassembly...
Any idea what to do?
Connectors and everything looks fine, but I can't believe touch screen stop working after disassembly.
Please help if You could...
Thank You!
You disassembled the phone? If you didn't put all the components back in place as it comes from factory and taped, then there could be grounding issues. There is a set of transistors next to the lcd connector and above the charging port, make sure it's touching the golden pad on bottom and is taped.
Or else it's a bad cable, bad grounding somehow, moisture issues etc etc.
I think You're right.
The set of transistors may not connecting well.
Can I use processor pasta to glue it back?
Or just some simple tape from above?
-----------------------------------------------------------
So I cleaned it with alcohol and the original glue getting stronger, so I put it back to the right place and put some tape on it.
But still the same.
Do I have to put tape on the cables above the battery?
How could I find where is the bad grounding?
BBOutlaw said:
I think You're right.
The set of transistors may not connecting well.
Can I use processor pasta to glue it back?
Or just some simple tape from above?
-----------------------------------------------------------
So I cleaned it with alcohol and the original glue getting stronger, so I put it back to the right place and put some tape on it.
But still the same.
Do I have to put tape on the cables above the battery?
How could I find where is the bad grounding?
Click to expand...
Click to collapse
No i don't recommend to put thermal paste therez if it conductive it can short nearby components and can also get messy, it is only for using on chips. I suggest you use double sided tape, but do it strategically so that it leaves a small portion open for the golden pad to make contact. And after that you put nonconductive tape on top of that. Make sure the metal part of the white cable nearby is not touching this area, or you can also put tape between them. I suggest to put tape on the lcd connector as well.
Whenever this problem arises, and if you have trouble to fix it, an easy way is to disconnect and reconnect the battery after a few seconds, should work ok.
You can also purchase a new one like this, look for your device model - https://m.ebay.com/itm/183023879505
crophs said:
No i don't recommend to put thermal paste therez if it conductive it can short nearby components and can also get messy, it is only for using on chips. I suggest you use double sided tape, but do it strategically so that it leaves a small portion open for the golden pad to make contact. And after that you put nonconductive tape on top of that. Make sure the metal part of the white cable nearby is not touching this area, or you can also put tape between them. I suggest to put tape on the lcd connector as well.
Whenever this problem arises, and if you have trouble to fix it, an easy way is to disconnect and reconnect the battery after a few seconds, should work ok.
You can also purchase a new one like this, look for your device model - https://m.ebay.com/itm/183023879505
Click to expand...
Click to collapse
Seems like the set of transistors well connected now and I put tapes on it and on the screen connector as well.
And I reconnected the battery too, but nothing happened.
It's the same as before.
And if I replace the charging port flex cable to the old one, it's the same too, but before disassembly it works, but the problem was I cannot charge the phone.
Any other idea what should I do to fix it?
I cannot choose D802 on the link You gave me...
Anyway I think this one and the old one is fine if it's about the touch screen, have to be something another...
BBOutlaw said:
Seems like the set of transistors well connected now and I put tapes on it and on the screen connector as well.
And I reconnected the battery too, but nothing happened.
It's the same as before.
And if I replace the charging port flex cable to the old one, it's the same too, but before disassembly it works, but the problem was I cannot charge the phone.
Any other idea what should I do to fix it?
I cannot choose D802 on the link You gave me...
Anyway I think this one and the old one is fine if it's about the touch screen, have to be something another...
Click to expand...
Click to collapse
You need to read carefully what i wrote, hope someone else finds time to help you.
crophs said:
You need to read carefully what i wrote, hope someone else finds time to help you.
Click to expand...
Click to collapse
I think I did as You told me... :/
I hope so and Thank You for trying to help me!

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