[BUG FIX] Phantom keypress and screen shot

[neh4pres]

I finally got around to mod'ing our last phone. Actually, I was finally able to pry it from my teen's hands long enough to do the work. I think she sat home all afternoon and twitched.

Anyway, here's a pic of the two caps. One is on the interrupt line and the other is on the clock (or scl) line. I melted the insulation from a piece of real fine magnet wire to connect between the clock pin and the second cap. The other end of the second cap is just solder bridged to the same ground as the first cap.

Nice work. Why 2 caps this time?

Sent from my SCH-I535 using xda premium

 

[electric bill]

Nice work. Why 2 caps this time?

Sent from my SCH-I535 using xda premium

I ended up with two caps from my original research but I had taken the previously posted set of pics before I added the second one. It seems the RFI was getting on the clock line and creating random clock toggles along with random data. This was causing the melfas chip to turn the backlights on and off as well as generate a false interrupt. The main problem was the random interrupts caused by RFI, and the first cap on the interrupt line fixes that. The second cap on the clock line snuffs out those last little problems that only show up rarely in very low signal areas. Most of the time, when you get into an area with signal that low, the phone switches to 1X and you don't see the problem. But as long as the phone is open and the soldering iron is hot, it only makes sense to add both caps.

 

[Ralstian]

Cap Values?

I'm constantly amazed by what the community here at xda comes up with. You guys are amazing. My wife just got a Galaxy s3 today and I'm annexing her old Fascinate to use as my primary phone/media player for when I'm at work. I just saw this post and it explains so much of what here strange issues were!

The question I have is, what capacitor is that exactly. I see that it is a 100 pF capacitor, but I'm searching around mouser's webpage, and I'm not sure which 100 pF cap to get, there are thousands of varieties! What do i need as far as voltage rating, tolerance etc. I have access so the necessary equipment at my workplace to safely perform this hardware fix, so I just need to go ahead and order the caps.


Thank you all so much, and keep up the kick*** work.

:good:

 

[electric bill]

I'm constantly amazed by what the community here at xda comes up with. You guys are amazing. My wife just got a Galaxy s3 today and I'm annexing her old Fascinate to use as my primary phone/media player for when I'm at work. I just saw this post and it explains so much of what here strange issues were!

The question I have is, what capacitor is that exactly. I see that it is a 100 pF capacitor, but I'm searching around mouser's webpage, and I'm not sure which 100 pF cap to get, there are thousands of varieties! What do i need as far as voltage rating, tolerance etc. I have access so the necessary equipment at my workplace to safely perform this hardware fix, so I just need to go ahead and order the caps.


Thank you all so much, and keep up the kick*** work.

:good:

it's an X7R. TDK part number C1608X7R1H101K. But I bought a 100 of them from digikey when I got them. PM your address and I'll send you a few.

 

[hudson_macbeth]

Awesome work, Bill! I've got 3 mesmerizes that all have this issue, so I may just have to do the cap mod myself. How much would you charge me for 8 of them? (In case my tweezers spit one or two across the floor.)

 

[electric bill]

Awesome work, Bill! I've got 3 mesmerizes that all have this issue, so I may just have to do the cap mod myself. How much would you charge me for 8 of them? (In case my tweezers spit one or two across the floor.)

just pm your address.

 

[longplaypg]

First a big thanks to Electric Bill and the folks who worked with him on this issue.

I have received my CAPS, but I cannot find my Intel Play USB microscope.
en.wikipedia.org/wiki/Intel_Play

I am going to move forward by purchasing an AGPtek USB Microscope for now.
newegg.com/Product/Product.aspx?Item=9SIA0U00AH2235

I am planning on doing the 2 CAP fix for now in hopes of permanently removing the phantom keys issue from my device. This should also stop those annoying short battery life times when the phantom keys go crazy, heat up the battery, and decrease my overall battery life. I know not all my battery issues are from the phantom keys, but definitely a few of them I have tracked.

I will post more once the microscope arrives.

 

[electric bill]

Seems a shame to have to go out and buy a new microscope. It doesn't have to be very powerful. Maybe the local high school has one that they'd let you use for a day.

First a big thanks to Electric Bill and the folks who worked with him on this issue.

I have received my CAPS, but I cannot find my Intel Play USB microscope.
en.wikipedia.org/wiki/Intel_Play

I am going to move forward by purchasing an AGPtek USB Microscope for now.
newegg.com/Product/Product.aspx?Item=9SIA0U00AH2235

I am planning on doing the 2 CAP fix for now in hopes of permanently removing the phantom keys issue from my device. This should also stop those annoying short battery life times when the phantom keys go crazy, heat up the battery, and decrease my overall battery life. I know not all my battery issues are from the phantom keys, but definitely a few of them I have tracked.

I will post more once the microscope arrives.

 

[locoboi187]

This is a very interesting thread. Subscribed.

Sent from my SPH-D710 using xda premium

 

[pcmanager]

Thanks for all your work troubleshooting this issue Bill. It's great to have skills like yours and share your discoveries with the community. I have a Samsung galaxy s2, plagued by the phantom presses. I have disabled the keys and use onscreen nav keys for a bandaid fix. I would love to try the cap fix, as I will be keeping my phone until may 2013. Took the phone to sprint and they claimed liquid damage... The indicator sticker hadn't even changed color. PM sent. Thanks buddy!

Sent from my SPH-D710 using Tapatalk 2

 

[longplaypg]

Seems a shame to have to go out and buy a new microscope. It doesn't have to be very powerful. Maybe the local high school has one that they'd let you use for a day.

The new microscope has 8 leds that light up the area nicely. The boy and myself will get some good use out of this little unit anyways.

I am doing a pre check list today and planning my final attack on this issue.

In your first mod (1 cap) you have a rev1.1 r.b45 circuit using a MFS 5mj44 ???85 chip.

In your second mod (2 cap) you have a rev1.0 r.aa2 circuit using a MFS 5mj24 1041a chip.

My unit has a rev1.0 r.ab2 circuit using a MFS 5mj16 10312 chip.

Based on your previous 2 phones and my phone I should have no issues, but to feel safe I want to confirm the pin outs match before I proceed. I will do a little internet searching to see what I can find before I dive in blind.

Attached are a few pictures I have grabbed so far with the new microscope. I so far see I need a better stand and might want to break it open. It seems to me the camera lens inside needs to be rotated or design a special stand to deal with the rotated lens.

 

[electric bill]

good catch on the different part markings. The MFS is probably melfas. the last numbers are likely the date code. I sent an email to Melfas and asked for the data sheet for the MFS-5080 part

 

[longplaypg]

good catch on the different part markings. The MFS is probably melfas. the last numbers are likely the date code. I sent an email to Melfas and asked for the data sheet for the MFS-5080 part

sounds good I will not harass them with a 2nd email requesting the same then

I have never soldered this small before and decided to try a few practice runs to get a little familiar with things. Going to break for lunch and give myself a little relaxation. Here is a real nice picture of the chip and surrounding pins that you can use to improve your documentation with, that doesn't contain the caps yet.

 

[electric bill]

for some reason I can't view any of the images that you've posted

 

[longplaypg]

for some reason I can't view any of the images that you've posted

I can not post outside links. I thought attachments would work since I could see them. Just visit my skydrive for now.
skydrive.live.com/redir?resid=ECA7231EE084EB06!461

 

[electric bill]

turns out it's not you, it's me..... or really the firewall here at work is blocking the images.

 

[electric bill]

I have never soldered this small before and decided to try a few practice runs to get a little familiar with things. Going to break for lunch and give myself a little relaxation. Here is a real nice picture of the chip and surrounding pins that you can use to improve your documentation with, that doesn't contain the caps yet.

don't let that flex circuit get too hot or the solder resist will come off the top of those traces and the copper will be exposed to shorting out the parts that you are mounting on top of them.

 

[hhp_211]

don't let that flex circuit get too hot or the solder resist will come off the top of those traces and the copper will be exposed to shorting out the parts that you are mounting on top of them.

what is a good solder iron temp for this,,, although I highly doubt I'll ever be doing it,,,I love to 'think' I have the knowledge

Sent from my SCH-I500 using xda premium

 

[electric bill]

sounds good I will not harass them with a 2nd email requesting the same then

I have never soldered this small before and decided to try a few practice runs to get a little familiar with things. Going to break for lunch and give myself a little relaxation. Here is a real nice picture of the chip and surrounding pins that you can use to improve your documentation with, that doesn't contain the caps yet.

found a couple of places to get replacements for the touchkey assy. ebay had a couple of listings. Just go there and search for "Samsung i500 Galaxy S Fascinate Front Home Menu Touch Keys Flex Cable". I'll prob order 1 just to check it out.

repairsuniverse.com is also selling them.

 

[longplaypg]

found a couple of places to get replacements for the touchkey assy. ebay had a couple of listings. Just go there and search for "Samsung i500 Galaxy S Fascinate Front Home Menu Touch Keys Flex Cable". I'll prob order 1 just to check it out.

repairsuniverse.com is also selling them.

Ok real life took over and will continue through this weekend

At this time I took a few more snapshots and some rough measurements. I have a hakko703 with a hakko907 iron. I believe my LB is just too big at this point for the small parts just trying to do some off board soldering. I have decided to add like pigtails to these parts so when I get ready to solder on that flex board I will have 3 small soldier points. It might be easier to do the soldier bridge, but I wanted to stay away from that flex circuit for now. I will check out your source and maybe buy a spare

Going to look for a smaller tip for the iron and see if things are easier.

All of these pictures have rough measurements in millimeters displayed on them.