yashsingh1/xdaforums huggingface dataset:
[HD2 General] motoi_bogdan:
bad news..

so i did get another hd2 to experiment on it. it had the same thermal problem so i proceeded to my solution. However... this one died during the process. Although various things were tried to resurrect the device, it still remains dead. I suspect either the isopropylic alcohol used during the cleaning process, it was not pure enough, either cavitation effect during ultrasonic cleaning, or too much heat when reheating the cpu.. in what order they arrived, it only made it worse, the thing just died (it doesn't turn on, bga failure followed by psu failure caused by a short circuit under the cpu - at bga level).

So i'm kind of pissed out now :( , yet some sad things were learned and they make things even harder now.

- no amount of heat sinks will solve this problem. Neither the one proposed by me. That's because the problem is located at the bga level and is kind of physical by nature (dilatation and contractions of the soldering points). Once failure has occurred, no amount of heat sinking will help, the solder points must be remade, otherwise, if the problem takes place at 20 degrees (for example), simply adding some heat sink won't cool the ambient temperature. So if your phone freezes at 20 degrees, it will do so, either with or without a cooling system.

- the success or failure of this simply relies on reheating the cpu. Simple as this. If you get lucky, you can melt the broken bga balls and restore them to some working state (my first hd2 - it still works flawlessly even today, after the procedure) but if the damage is to extensive or located in certain areas (center of the chip surface for example) reheating won't work or could simply kill the phone (second hd2 died probably because of this).

- pressure remains relevant along with reheating. It could help on keeping the chip on it's position and pressing on the bga matrix. However, how much is needed or if it's better or not in the long run still remains a mystery.

So i would kindly ask for anyone reading this to STOP trying to fabricate various heat sinks for HD2, it simply can't work. Mine did because of reheating done with a specialized smd rework station. Even with that, and some experience doing such things, the second device died. It's pretty much lottery. IF you get lucky you have a chance on fixing it, if not.. well, you brick the phone. Really brick it and no service center will be able to fix it.

I apologize for various inconvenients caused to people who either tried this or are willing to try, it seems we're not there yet. There is no simple or reliable way to fix this, and with whatever equipment on my disposal i simply could not beat the inevitable with the second device.

So.. guys.. does anyone know where to get a second hand hd2 motherboard, ebay or other stuff ? :)

Either way, i'm left with a dead motherboard. There's still some things to be found out and i wasn't able to answer to them without ripping the guts out on hd2's motherboard. So.. anyone curious on how the crappy soldering under the cpu looks like? Guess that snapdragon chip must ...pop out.
[HD2 General] januszgorlewski:
ebay is your guide here for motherboard i guess, as noone sell them off like that...

I am sorry to hear that device died :( but still you can do some research for yourself i think, by desoldering cpu and checking what sort of things happening under.

would love to see what on the heart beats... ;)
[HD2 General] Hammerfest:
would love to see more detailed pics of the mainboard and its "attachment" fetish :P

I am planning on doing a cooling mod like this (sans reheat, just TP and HS, er thats ThermalPaste/HeatSink) if I ever get the chance/dare :P

(i must have a fetish for this crap, i love buying laptops with issues and fixing them... me olde trusty soldering iron... ok.. that one died... new radioshack POS in use now...)
[HD2 General] motoi_bogdan:
will do.. i just happen to have one dead hd2 motherboard, as stated above. i have a short circuit al bga level, underneath the chip, so there is no solving for that one. Also, thought about desoldering the cpu but that resin is very hard to remove indeed.

Simply adding cooling systems on top of the cpu won't solve the problem. The chip must also be reheated, but at this time i had 50-50 chance for success on doing that. One made it (tmous) one died (eu).

I too have that kind of a fetish. I learn to repair phones via jtag because some couple of dead ones that could be repaired only by this method. But i'll take anything, laptops, desktops, pda's (my speciality - Ipaq's) tv's, gps navigation systems and so on. Started with the trusty old solder gun and an old analogic multimeter (that worked like crap). Now i have a desk full of funky equipments.
[HD2 General] Timsomor:
Just tried this fix with all the right stuff and my phone will not turn back on Just tried the cooling fix. Had all the right stuff even wore anti static gloves and strap, watch two different videos while working and used the mica on the cpu method with copper on the metal case of the touch screen. I will redo steps tomorrow but this does not look good.

Update May 15, 2011:

Watched all video, again as I did in the first place to see if I did not reconnect something after that I re disassembled the device checked all connections and looked to see if I left anything unconnected while back tracking my steps. I had everything connected correctly per this video (which had both full, supposed disassembling and reassembling):

Official HTC step-by-step video for disassembling the HTC HD2 at CrunchGear site (can't post link cause of only having 1 post.)

What I did First time:

Added thermal gel to two chips.

Placed Mica Pad over both chips in which I added the thermal gel.

put another layer of gel on top of the mica pads.

Next replaced the shield covering both chips.

Added three layers of copper tape to the metal side of the touch screen that would touch the shield cover chips directly.

Put gel on the shield and buttoned up the area.

Second time taken apart:

Believed I had blocked something from making contact when pressing the power button.

However, that was not the case.

Removed the the three layers of copper tape and checked the area for obstruction and damage, there was none.

did not remove the add ons I place on the two chips.

Put phone back together and still nothing (Expensive Brick is what I believe it's called Now)

Things to point out:

Plugged the phone in for a charge and the charge light does come on, however the battery had good charge in the beginning.

The area around the volume control can get tricky and on none of the videos do or the show you how the button should fit back in it's place.

Tools Used:

I am a PC Tech and Electronics tech, so I have taken apart several devices, built several of my own computers from the architecture level up, and know

how to use electronic measuring devices.

I used a full kit for the purpose of taking apart cell phones. (Star drivers, Plastic level tools, etc.)

ESD strapped all the way.

Checked myself to ground!

coated tools with Plastic or rubber.

Not sure of what went wrong but it's at the board level. Not sure this could be fixed, I believe if you were to return this device if still under

warranty you would receive a new one that had been modded.

I have to go low tech again back to my Motorola Razor. Glad I kept it. Did this experience now twice my previous supposed Hi Tech phone was the Meizu M8 which is now just a flash drive with icons cause the touch screen stopped working. I believed stuff made in Asia was the best stuff especially stuff made out of Japan. But nope, wrong on two level which are very costly to me right now.

Try at your own risk guys.

When did the consumer become the QC department for companies?

Just ask apple.
[HD2 General] Hammerfest:
DO NOT TRY THIS AT ALL...

You have been warned!

Ok, so got a "broken" HD2 off Craigslist for $20, was bricked I assumed, sent it in for $50 to get revived by MobileTechVideos.com, came back, used it for 15~min, freeze, thought it might be what i was doing (Emu), pulled batt, came back 5min later (drink in hand!) after 10min same thing, freeze! Pulled batt then tried again w/o waiting...

7 VIBRATIONS OF DOOOOOOMMMMM!!!!

Needless to say, I dont have a reballing station, a heating station, or even a heat gun! (used too... miss my heat gun... but dont miss the insane "shields" id have to fashion to protect other parts of a PDA (never did it on a phone)...

BUT I work on PC's/Laptop's all day... SOOOOO opened it up, got some of my old copper shims from my DV9000 (that still managed to break), cleaned it all up nice and perdy, put some arctic silver 5 on there...

Result: 2D... works fine... so far 2hrs no freeze... BUT any 3D or Video playback and within a min or 2 and it dies then does the 7 Vibrations of DOOOOM crap...

If only you lived in the USA id send you mine to repair... SHIIIIIIIT...

EDIT: lol, maybe if your skilled enough OP, you can remove the resin :P http://www.youtube.com/watch?v=kTPXKA66baQ (ok probably different kind or resin.. and i wouldn't use a metal tool for removal.. but you get my drift...) then you can start a reball service :D

WTB: HTC HD2 T-Mobile USA Mother/MainBoard... $60~
[HD2 General] RJC82:
No real problems with my HD2

Since yesterday I had the same problems. I feared it would be a slow decay from here and yet an other HTC device sent off to the bad repair center.

It seems my device had the freezes, but no reboots or such. When I looked at the cpu speed, it stayed at 1Ghz and didn't drop to lower speeds when idle. So I figured that would be why my battery drained super fast and the lower back of the device was getting hot. When I reduced the speeds manually, the freezes still did occur, but less frequent.

Today I read about a IMAP problem with Google mail. That problem was solved by Google and since today, there are no freezes, hot backs and battery drains anymore. When I force my device at full speed with a test, the freezes and stuff do happen again. So for me it was a false alarm. I hope the problems will stay away for now.
[HD2 General] DTNT:
I also read about it, but is it also an issue on HD2 with Android on board?? My start freezing more and more in short times. With SetVSL app it works about 1 hour just with easy apps, with Angry Birds it is freezes at 5-10 minutes. With internet surfung (3g) it freezes in 3-5 minute. So, when I take out sim card and leaving device to idle, it can stay awake without freezes 1.5-2.0 days (upto battery). So what is a problem. Do I need to open my device and wear heatsink on as described in the beginnign of this theme?!
[HD2 General] ahmetsandal:
Dude, you succeed or not, whatever the result will be... I believe that you are doing a great job. You are trying to understand a real problem which htc and its suppliers deny. Great job, great effort... Additionaly, this is one of the best posts I've ever read: Whole post focuses on just the problem and the solution; there are no speculations etc. Thanks a lot.

PS: I have the same problem and I will be taking it to the service center tomarrow because I do not have appropriate tools to try. :(
[HD2 General] DTNT:
My problems solved only this way!!! Get ice cubes from the freezer, put them into plastic bag, did like a cradle with this ice-cubed bag and put your HD2 on it. NO MORE FREEZES!!! Even with Angry Birds and 3G working and downloadings. But all this Happiness until ice melt down!!! XDA devs please find material that will last iced for a long time :). I think there is no options! So, now my HD2 has an accessory and it is - big 2 camera Daewoo Refregerator! Cool!!! Do you have one?!
[HD2 General] motoi_bogdan:
well, this will normally work because you actively cool the device below the thermal point at witch you have problems.

Along with my reheating solution, designing an active cooling system can also do the job. But i don't see how you can stick a cooling fan inside the phone's casing. :D

Another more exotic way to do it is to mount a small peltiere effect cell inside the phone. This thing has the property to remove heat from one side of it and transfer it to the other side - when powered by a small electric current. In simple terms that's how it works but ... i don't know if it's possible to find a cell that small and another drawback is the constant power consumption of the peltiere cell.
[HD2 General] Hammerfest:
i cant afford shipping, but since its a dud anyway, id send u the HD2 mobo (only) if you wanted to take a whack at 66.6/100% success :P

Ill need to nuke it with simple green first to get of the thermal paste first :P

( a thought i tried was leaving the device on, wrapping it up, and purposely letting it overheat to extremes, and GOD DAMN does it get hot, i was sure a few more hours and the thing would have melted!!!! VERY BADDDDDDDDD, needless to say, it has worked on many a XBOX, but for the HD2.. sadly not!)
[HD2 General] atjong1:
Any luck on finding a replacement motherboard on the internet?
[HD2 General] motoi_bogdan:
i bought a whole hd2 from ebay. it had this and other problems and was sold as parts. I'm interested in the motherboard only. However, the shipment was not the problem, but.. customs in my country. I have to pay 24%vat + some 8-12% customs tax, all this applied to the value at witch i bought it from ebay. That's kind of expensive. I'm still awaiting the phone, will see what i can salvage from it when it arrives.

@Kane3162 keep the board. If i kill the new one, i could be interested in yours :D Right now i also can't afford to get another board.

aah, and i have one good looking eu hd2 and awaiting for a very bad looking tmous one. I'll be also looking to see how can i place a tmous motherboard in an eu phone (what needs to be changed since they aren't exactly compatible).
[HD2 General] Ev0luti0n_:
**** i also bought a 2nd hand hd2 and all works well but i am scared to death now. omg omg omg panic
[HD2 General] Ev0luti0n_:
facdemol: so i had an idea.... what about getting a spare case and doing some openings on it? sure a bit of dust will get in, but won't we be able to cool the phone a bit this way? Or even cut a large rectangle in the base of the phone and glue a "large" grid there, that will allow the phone to cool down, i think....

What do you think man?

and what are your advices about using an HD2 without problems so far?

sort of what things can you do that will diminish the problem?
[HD2 General] motoi_bogdan:
noup, a spare case with ...holes or anything like that won't work.

you're thinking the problem just as some computer cpu overheat problem. Like when you buy a quad-core cpu and cool it down with a stock sempron cooler, or something like that. In this example, the quad core cpu may overheat because of the insufficient cooling, so adding a bigger cooler, improving the airflow or stuff like that will work on cooling the cpu down. The ideea is that, the cpu was overheating due to an improper cooling system.

Regarding HD2, well it's a different story. The cpu itself DOESN'T overheat, it stays in the normal temperature range specified by the chip's manufacturer, Qualcomm. The CPU is design to handle such temperatures, even double the amount it gets by working on the HD2's platform. When the phone freezes or restarts, this is not actually the CPU that has failed. Even the 7 vibrate pattern doesn't directly indicate overheating. The trouble is.. the chip connection to the motherboard. It's made via a BGA (ball grid array) connection, using a low Pb. solder alloy. This is the part that fails due to heat generated by the chip. Those balls crack and the electrical contact they were making is now broken. The CPU "senses" this as a hard fault, it was simply processing some data and out of sudden it was stopped. Then if, the contacts aren't made at the next restart, it signals the fault via the 7 vibrate pattern.

If things get out of control and you get left with a phone that restarts or locks at about 30 degrees celsius, even if you stick a big computer cpu cooler on top of it, it won't help. No matter how big is your hunk of metal, it will still be at room temperature when you start the phone. And if this is higher then 30 degrees, no amount of passive cooling will do.

So in simpler terms, let's suppose you have a phone that locks at 30 degrees. There are 2 ways to solve the problem.

- stick a big active cooling system (fans, peltiere effect cells, water cooling) - a thing that can actively decrease the cpu temperature below the 30 degree level. Of course, not practical, whatever you get by doing this won't resemble a phone :rolleyes:

- remake the BGA soldering between the CPU and Motherboard. It's the logical thing, that's the place where the actual problem is located. This can only be done by either reheating the CPU with specialized equipment or actually removing it, remaking the bga (replacing the ball array) and soldering back the cpu, but that implies even more specialized equipment.
[HD2 General] Hammerfest:
yep, wish i had that equip... (and ypu can be sure as **** id replace the ****ty solder they used with the highest quality **** i could find...)

and for info incase u ever make the req, mines a TMoUS HD2 (of course)

@those who keep asking, the extra cooling will help... just not enough to even matter... the problem lies under the chip itself where the "thermal runaway" occurs... with the exception of a reball theres 0 recovery chance....
[HD2 General] motoi_bogdan:
i've updated post #1 with some pictures of the snapdragon chip. I've removed it from an eu hd2 board and i'm currently studying it and it's board for some future solutions for this problem.

The chip itself is pretty small, kind of 1x1cm and 3-4mm thick. :p Looks pretty geeky and smart.
[HD2 General] Ev0luti0n_:
Thanks! so in the long term, will this happen to pratically all HD2, if not all? there are folks overclocking it to 1.3 on android! darn!

got start stocking some spare parts for me :D

facdemol: i still think that cutting holes in strategic places on the case would bring some extra cooling to the phone. I am not into electronics, beyond very basic stuff, but the more cooler the better, so... see my point? think about just a whole to extract heat with nothing forcing the air through. Not much, but something :)
[HD2 General] motoi_bogdan:
not all hd2's will develop this. From what i see, tmous ones have better cpu soldering then european versions. But, i should state that i've only seen 4 devices so far. I do not have specialised equipment to test the solder material and it's properties, but from about 15 years of experience with soldering alloys it seems that the tmous ones have more led in the solder alloy and that makes the solder points a bit more flexible.

Anyway, i've received a broken tmous hd2 yesterday. Weird problem, because of cpu overheating some contacts that link the volume buttons (that flex connetor) to the mainboard and from there, underneath the cpu itself, were broken (short circuit). So if the phone is heating up, the volume button will go crazy and switch on by itself. Even if i disconnected the whole flex cable, the problem will still be present.

Well this particular hd2 was recovered after reheating the cpu, no more restarts or freezes but the volume control was broken after that. I remade the connection, by polarizing the common collector transistors that provide the voltage needed for volume switching. For switching the transistors i used the voltage needed to power on the green led (signaling charge completed) thus disabling this led. But i've got volume control and the ability to get into the bootloader. The phone was fixed this way.

No cooling system was attached (be it copper,mica foils or aluminum) , only the cpu was reheated.

So, it's now two working hd2's versus one dead hd2. Reheating is the only way as far as i see the problem now. I'm glad i rescued another hd2.
[HD2 General] atjong1:
Good work!
[HD2 General] ubejd:
hi

a big thanks go for "facdemol" for his great share

i just want to share that i tried something... i went to a friend who has a bga rework station... first i just tried to rehoot cpu - i will make some tests and report here... if i dont succed i will try te remove entirely cpu and solder again ... i made some pic...
[HD2 General] motoi_bogdan:
it's good if you have access to such equipment. Here are some tips, although the person who has that smd station should also know them.

Preheat the cpu from both sides, starting with the opposite side then switching to the front side (the side on witch the cpu is soldered). Don't use more then 200 degrees for preheating, the way i see it now, i guess only 180 degrees could be enough.

Try to be as quick as possible in the main heating part. It's better to heat it for some minutes, let it cool down, test it, then redo the process if needed. I never had success in one single turn and i also recommend to do the process in small steps.

Try not to use more then 360 degrees on the main heating stage. Compared to other chips, i find the hd2's cpu's soldering very easy to melt.

If you plan to remove the cpu, you will need some solder balls and a tool to form them on the chip's pinnout. I don't know the name of this tool in english but you really need to have it. Without it you can't resolder the chip back and as hard as i searched i didn't find any for the Snapdragon chips.

Good luck with the process.
[HD2 General] ubejd:
I did so...

i will try again...

for heating i tried 190 - 210 degrees ( Celsius )

he has some but those where for laptops graphic cards... we are searching for right one... i hope i could find otherwise we will have to improvise something ( if we could)

Thanks ... we will need
[HD2 General] motoi_bogdan:
this is the snapdragon's back

as we can see, it seems that the pins are placed in a somewhat particular design, not evenly spaced, so other pin rows are spaced further apart from inner ones. Most bga are comprised of evenly spaced pins, it would be difficult to try to improvise. Also, most bga graphic chips have different pin spacing.

All in all, i guess that the idea is not to kill the soldering :D, it would be very hard to remake those connections.

Try to test after each round of reheating. I would recommend the first round not to exceed more then 1-2 min at around 360 degrees. It may look like you're not actually melting anything under the chip, but i'm a bit scarred on how easy that chip came off when i desoldered it. The ceramic cover (chip itself) seems to be very thermal conductive.
[HD2 General] ubejd:
I will reheat later today again with a temp around 220-250 just to see how things go.
[HD2 General] ubejd:
i have a bad news:( .... after reheating my keypad flex and volume keys dont work... im able to power on but it shows fatal hit ( i was using wp7 in nand) i thought to flash again but i cant... until i find a solution to this or i hope i can find original part ( thats very hard) i wouldnt be able to test.. sorry for that guys...
[HD2 General] Ev0luti0n_:
that is so bad to hear about :| hope you solve the problem soon!
[HD2 General] motoi_bogdan:
sorry to hear that.

the hd2 i received had a similar problem, volume buttons didn't work, also the windows and back keys from the front keypad didn't work. I assumed that it is related to the cpu's thermal problem, the corresponding pins for these functions got disabled or broken in some way. After reheating i was able to solve the thermal problem and so, the phone doesn't freeze or restart by itself. BUT the volume buttons were still unavailable, so i had to solve the problem by rerouting some connections. The font keypad still doesn't work properly but at least, the red/green call buttons and the home button still work, i won't risk another reheat only to fix that.

You should reattempt to reheat the chip, what happened the first time is that you further desoldered some of the bga balls. With some luck you may get them soldered back. You don't have a short circuit there, the possibility of that is very small, should you had one i'm almost 100% sure that the phone wouldn't even start - been there, done that.