As some of you may know, ii have refurbished tablet as my replacement. My question is that does the finger prints and crumpling of the foil affect the lifetime of the foil and the protection of the tablet from electromagnetic interference. Thanks for all the help so far.
After opening my Nexus 7 from Play Store and taking off back, mine has fingerprints as well. It's just part of the manufacturing process I think.
I always thought the copper tape was for heat dissipation. Magnetic fields don't really affect electronics except for hard drives. So I think it will be fine if your tablet isn't getting too hot
neotekz said:
I always thought the copper tape was for heat dissipation. Magnetic fields don't really affect electronics except for hard drives.
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Click to collapse
That last bit is only true because the copper tape is there.
Magnetic fields are produced by changes in voltage, and 'electronics' by definition are things that change (and/or are changed by) voltage (and/or current). Such as the USB signals in the yellow ribbon cable, or the signals in in the circuit board, or the wifi signal being sent & received by the antennae in the case back. Unshielded, these signals would interfere with each other and nothing would work. A grounded copper sheet between them reduces or eliminates such interference/crosstalk in both directions.
Related
Ever notice how there are two metal pins on the back that make contact with the metal cover? Why did HTC put them in there?
Also would one be able to hardwire the antenna too these points so that the metal battery cover can be used as an extended antenna?
msoler8785 said:
Ever notice how there are two metal pins on the back that make contact with the metal cover? Why did HTC put them in there?
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Click to collapse
They are probably there to cushion the force of the back place being clicked on.
msoler8785 said:
Also would one be able to hardwire the antenna too these points so that the metal battery cover can be used as an extended antenna?
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Click to collapse
Not a chance, have you ever pulled a HD2 apart? I severely doubt it is a wise idea. Hardware modding of a phone is a fools game.
Is it to dissipate heat?
It's for the car GPS kit.
jdwrrzmm said:
It's for the car GPS kit.
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Click to collapse
Not the 3 pins, the 2 balls on either side of the phone.
Is it really for a GPS kit? Maybe that concept kit that HTC never came out with? But what would they do it can't be for power.
Sent from my HTC HD2 using XDA App
This comes up every month or so, and i agree with Kalavere in that they are there to keep the back plate snug. They are spring loaded, so the plate wont get wobbly with extended clicking on/off. Since the reset button is under the back panel, it seems reasonable that HTC would expect the plate to be removed fairly often.
I also think it plausible that they are earthing points for the antenna, but i think that a little less unlikely.
Not sure exactly what they are for but I am positive they are not there to keep the backplate snug.
They are some kind of a contact point. The metal cover bridges the connection. You will notice that the cover is clean where the points contact.
Never seen the car kit but that is a possibility. I doubt very much that they have anything to do with the antenna. My guess is that they might simply be a ground shield.
I had the same question, I rung up the HTC support here and they told me that even they are not sure, but they did mention that on the inside, it's linked to the antenna for the GPS. Don't know what they mean by that but I guess, it's either an earth (since, if you notice, the area where the nobs rest has the paint scrapped off), or the whole back plate is an antenna. I tried to insulate it, no diff to operations of the GPS or Phone.. *shrug*
msoler8785 said:
Ever notice how there are two metal pins on the back that make contact with the metal cover? Why did HTC put them in there?
Also would one be able to hardwire the antenna too these points so that the metal battery cover can be used as an extended antenna?
Click to expand...
Click to collapse
Hi all,
I have recently been repairing iphones and while doing this I have notice something in their construction that I thought we should have. Both the iphone 3 and 4 have a mylar mirror coating on the rear of the LCD to reflect heat away from the lcd and touchscreen, and it really works well. If you have an Iphone check it out, even when the cpu is flying the back gets hot but the screen stays cool. This got me thinking about the vega and how hot it gets running roms like VegaICS and Vegacomb. This can make touchscreens wig out and is uncomfortable. The design is flawed. There is a Mylar sheet in the vega but its completly in the wrong place. It is in the right place to be an RF sheild (thats probably what its for) but for cooling its about as much use as a 3 bar fire. When I am using my vega (playing games) it gets so hot inside that I can feel the heat flowing out of the hole for the dock connector. If I lay back, with the bottom of the vega resting on my stomach and I have a tee shirt on it gets hot enough to become uncomfortable so I have to move it. The Mylar sheet stuck to the back of the vega is reflecting heat back at the motherboard LCD and touchscreen like a little oven. The only place for the heat to escape is through the LCD, touchscreen and the other small gaps and holes around the vega. The metal panel bettween the LCD and motherboard will slow down the heating of the touchscreen but not much and will probably just be trapping heat when it gets up to temperature.
So to cool down the vega.
This is really simple. I ordered a small sheet of dimple mylar off eBay (non-conductive and disapates heat better than normal mylar preventing heat spots. apparently. I have put it under the motherboard and on the back of the LCD. I also removed the mylar from the back of the rear panel. For good measure I cut a pieces of aluminum off a PC heat sink and fixed them to the Tegra chip and the ram chips (with alaska sheet type heat sink stuff, that's a technical term ). The heat sinks are probably overkill but it cant hurt and may meen overclocking will be cooler and therfore more stable.
I tested it with and without the heat sinks and the overall temperature is significantly cooler on both. The screen now stays cool all the time, even when charging and using the cpu hard. The back still gets warm but no where near as hot as before. With the Addition of the heat sinks didn't noticably reduce the temperature but they will come into play when ICS gets overclocked.
A nice side effect is the charger no longer causes the touchscreen to freak out (altough this could be eduardo's new driver). Fine accuracy is reduced while plugged in but the screen no longer double/phantom clicks and is usable for everything but drawing.
Overall I am really happy with the mod. It's cheap and easy to do and cools the vega a lot. Next time I have the back off I may add another peice near the charge jack to try to completly remove the charge/accuracy problem. I have not noticed any problems with interferance caused by removing the mylar off the inside of the back panel although my neibours telly could be going haywire without me knowing (not my problem).
Heres some pictures of what I did.
The back of the LCD covered with mylar (hard to get a good picure because of the reflection.
The metal panel back in with more mylar where the battery and motherboard are mounted, holes cut in mylar for the motherboard mounting screws.
Everything back in except the battery.
This show the original mylar sheet and where it was inside the back panel. Now removed and binned.
The heat sinks
Running as cool as a cucumber B)
Amazing work, i have a Ployer Momo9, well it's more like a clone of that tablet, when i updated it to ICS it went ok, but sometimes i had random crashes, i used to have a small flat heatsink from an old motherboard wich still had the self-adhesive; so one day i finally gutted up and cracked open the tablet, placed the heatsink and had to say that now it doesn't crash.
I started googling to see if some1 had done the same with other tablet, i found your post and now i guess ill try the same with the mylar, wich can't find by the way, i have some aluminum sheet but i guess it's a bad idea to put some conductor as a heatshield
@richardmlea
awesome work
Typically the issue on our phones is that the magnetic port pulls out after a lot of use. I had this and I superglued that sucker back in. Now, I have a whole new issue. One of the little nubs with the metal contact completely came off! I seriously have no idea how they could have happened. It's hard to describe but I'll take a picture when I can to show this. The annoying thing is that I superglued this one in very well. I would have to seriously risk breaking more things to pry this one off to replace it! Despite no update to marshmallow (D6616) and these crazy build issues I still don't see a compelling new phone to replace this one -_-.
Pics. Initially, the little metal circle was gone. I scraped away the rest of the little black circle to expose the little bit of metal that is still sticking out. I can still use the magnetic charging port as long as I carefully attach it in a way that the little metal piece makes contact with the charger.
Please make a photo of your magnetic cable connector too
When the microphone of my z3 broke, the service changed all the frame of my mobile.
i was so happy, my old magnetic charging port was very worn out (almost like your picture)
I blame users using cheap magnetic cables bought from ebay and amazon because of this. Magnets can be super strong, strong, medium, and weak. Mine has been fine since owning the phone Dec 2014. I use the Sony magnetic dock and always charge on it. The only problem I have is that it needs a backbone to charge because DUE TO MY FAULT, when the phone dropped, it bent the trim area of the magnetic port.
People always need to point fingers at everyone besides themselves.
lvlonkey said:
Pics. Initially, the little metal circle was gone. I scraped away the rest of the little black circle to expose the little bit of metal that is still sticking out. I can still use the magnetic charging port as long as I carefully attach it in a way that the little metal piece makes contact with the charger.
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Click to collapse
By the condition of your phone from the pics you posted I'm not surprised. I have 2 magnetic chargers and non have this issue. The magnets are relatively weak - just strong enough to hold the cable to th phone while moving it around - and I've not experienced any issues although my charging port doesn't look near as haggard as the ops.
Sent from my D6603 using Tapatalk
I use the magnector connector which is what initially caused my magnetic port to pull out. My magnetic port looks all jacked up because I superglued the port back in but got messy with the glue and had to scrape some off. Anyways despite how messed up my magnetic port looks, the rest of my phone is actually pretty much in new condition. I have had it in a case all its life and a glass screen protector.
Sorry for the noob question, but I have this new "core board" in the attached picture.
Do I just need to glue a heat sink to the silver part, obviously moving the cord out of the way?
Is it that simple, or are there certain spots to avoid?
I wonder if this drilled plate can be removed just to check its alignment to chip. Having just a fan above this (attached to HU's walls) might turn better solution.
ste2002 said:
I wonder if this drilled plate can be removed just to check its alignment to chip. Having just a fan above this (attached to HU's walls) might turn better solution.
Click to expand...
Click to collapse
So just remove the screws and see what is under there?
Yes. Some of us report that thermal paste is missing/no contact with plate etc. Such setup as in your photo - I've never seen yet though, but it is good to make sure the contact is properly arranged - then additional heatsink makes sense.
So if something is not touching the top part, a heat sink will do nothing?
I took the heat sink off mine. It did appear to have good contact with all the chips, but before replacing it, I spread the heatsink compound evenly across all the chips.
Then I added extra heatsinks on top with thermal adhesive, and added fan to top cover. See main heatsink thread for details, and read from beginning. Here's my post. https://forum.xda-developers.com/showpost.php?p=75274018&postcount=154
CadillacMike said:
So if something is not touching the top part, a heat sink will do nothing?
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Click to collapse
Even "better": it will block available vent holes. IMHO if there is no proper contact *and* no way it can be restored/arranged, then fan can do the cooling job via vent holes.
pwood999 said:
I took the heat sink off mine. It did appear to have good contact with all the chips, but before replacing it, I spread the heatsink compound evenly across all the chips.
Then I added extra heatsinks on top with thermal adhesive, and added fan to top cover. See main heatsink thread for details, and read from beginning. Here's my post. https://forum.xda-developers.com/showpost.php?p=75274018&postcount=154
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Click to collapse
It also acts to suppress RFI and acts as a heat spreader.
For my PX5 Android 6, I replaced the thermal compound on the heat spreader, added a heatsink and fan. Bonded using thermal adhesive, all parts repurposed from old laptop. Includes connectors, supply sourced from unit switched 5v which is powered off on sleep. Simple resistive voltage drop added results in cool temps and barely audible fan.
I have further modified the case top section to add a grill and filter medium.
ste2002 said:
I wonder if this drilled plate can be removed just to check its alignment to chip. Having just a fan above this (attached to HU's walls) might turn better solution.
Click to expand...
Click to collapse
Agree. Replace thermal compound and a fan either pulling hot air from or blowing cool air onto the SOM heat spreader and sourced externally should keep things cool.
Hi !
My K20 is dead now, even if I tested with the original battery which worked.
Please look at the photo.
It displays that at switch on, or nothing.
But I have a vibration.
Thanks for your help.
caperonjr said:
Hi !
My K20 is dead now, even if I tested with the original battery which worked.
Please look at the photo.
It displays that at switch on, or nothing.
But I have a vibration.
Thanks for your help.
Click to expand...
Click to collapse
I had the same problem on my K30 after a screen replacement.
I don't understand why I can't power on more my phone since I unplug then replug the battery.
Loose or damaged ribbon connector or cable.
Damaged display matrix or mobo.
Out of circuit displays and mobos are suspectable to ESD damage on their I/O's as these are not ESD harden.
Each time, flex cables replaced.
Last time, I ordered a new mobo, and it was ok, but next battery disconnect and reconnect, same problem, every time.
3 new mobos for the K20 !!
I do something wrong, and I need to know what !
caperonjr said:
Each time, flex cables replaced.
Last time, I ordered a new mobo, and it was ok, but next battery disconnect and reconnect, same problem, every time.
3 new mobos for the K20 !!
I do something wrong, and I need to know what !
Click to expand...
Click to collapse
ESD... observe ESD protocols. Raise room humidity to at least 50%. Use a ESD mat or a bare wooden surface. Use a ESD wrist strap that's earth grounded. Wear cotton clothing. Avoid generation of static as much as possible.
I've seen techs grossly mishandled mobos in terms of no ESD protection and get away with it.
Your mobo maybe more sensitive. If you can sense the presence of static electricity it's already way more than enough to do real damage. You become aware of ESD at around 1000 volts; I/O's may only tolerate 25 volts or less of over voltage.
Make sure you reassemble it exactly as it was. Be very careful not to damage connector pins or the cables. Take your time and do it right.
Impossible.
I repair phones for a long time, and I caused an electric damage on an iphone the first time, because I unpluged the battery flex connector with a metalic hook !
Since, ESD wrist strap and never other damage.
And when it happens, it appeatrs a significative spark.
Then the problem isn't that.
caperonjr said:
Impossible.
I repair phones for a long time, and I caused an electric damage on an iphone the first time, because I unpluged the battery flex connector with a metalic hook !
Since, ESD wrist strap and never other damage.
And when it happens, it appeatrs a significative spark.
Then the problem isn't that.
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Click to collapse
Very possible. ESD damage can happen even with what you thought were adequate safeguards. Best not to touch the I/O's at all.
You can't sense 200 volts of static but simply rubbing two pieces of paper together can generate well over 400 volts. Even anti static plastics generate static, the charge dissipates faster though. I have a 3M ESD meter and played around with it quit a bit... it takes very little static electricity to blow through the insulator of a MOS gate.
Relative humidity is the most important factor to limiting ESD by increasing the static bleed off rate. I used conductive flooring in my shop as well. The whole work bench was ESD matted/earth grounded. Earth grounded static safe soldering irons. I was careful to discharge myself after moving around before touching sensitive components.
Then it's sure my mobo is dead ?
And very curious I have the same issue each time I open this phone, and never others...
caperonjr said:
Then it's sure my mobo is dead ?
And very curious I have the same issue each time I open this phone, and never others...
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Click to collapse
It could be you missed something when you reassembled it. Sometimes a longer screw or the frame are used as a ground return or otherwise missing ground pathway. If there was battery swelling that could have damaged the display or if the battery removal was too forceful.
Connector pins and ribbon cables are fragile if not properly handled.
It could be a few things causing this.