yashsingh1/xdaforums huggingface dataset:
[Desire HD General] RogerL:
Will do. As I say, it seems the stock GPS antenna actually works really well, but there appear to be issues with where/how it is mounted relative to the rest of the phone. Further investigation needed me-thinks!
[Desire HD General] Hunt3r.j2:
Probably an issue with tolerances, flash cover wear/corrosion, and generally weak design...
[Desire HD General] RogerL:
Here's some pics of the shielding I put together, and some of my previous attempts at connecting the GPS cover.

I used some thin clear plastic sheet to mount adhesive aluminium tape which enabled a good solid shield to be made which could be shaped exactly to the contours of the cutout. The earth strap is connected via a modified ring connector to the mobo screw in the corner as in Agent Cain’s suggestion, and taped onto the shield. All good!

However, my antenna is now busted due to one of the mounts disintegrating after too much soldering, so I’ve ordered another off Ebay and will post back when that’s in place. I’ve made a temporary fix to the existing antenna, but the results are too variable to be reliable. However, it did get good reception for a while.

I’m also going to look at fitting small coil spring connectors over the mobo connectors, as I’m convinced they are the cause of much of the problems. I get the feeling that they just bend back and lose their tension too quickly resulting in a poor connection to the antenna. Coil springs should counter that, provided it’s possible to fit them.

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[Desire HD General] AgentCain:
Nice work! Just test it and watch the SNR levels.

Also a tip for anyone trying soldering the contacts. After soldering use a small file (tool) on the contacts, just to make them flat again and clean surficial flux residues.
[Desire HD General] TheAngelus:
nice fix ill have to try this one soon.
[Desire HD General] RogerL:
Hardware mod completed!

Fitted spring contacts as in the pics below. These were just cut down springs from a pen, positioned and fixed with just a touch of solder.

I received the replacement antenna, tried adding solder to the contacts, used too powerful a soldering iron and screwed up one of the contacts! I fudged it and it works again, but not sure if its 100%. I’m thinking that with the spring contacts, the solder is probably un-necessary anyway as the contact area is now bigger and stronger. May buy yet another off Ebay £4.99 just to be sure.

However, it does seem to work fine, and there was an immediate improvement in SNR levels, speed of fix, accuracy of position and number of sats! (as in the pic below) So I’m pretty happy with the mod. I think the spring contacts will reduce the chance of the signal deteriorating over time due to the contacts losing their tension.

It’s hard to say for sure whether the shielding has improved the situation, but from what I’ve found it does seem to have increased signal strength.

Only thing is, now that I’m happy that the hardware is good, I’m convinced that there is a software issue. For example, when I tested the GPS after completing the mod, and getting good results, when I tried it again about half an hour later, it took ages to get a fix, didn't pick up as many sats, though the SNR levels were still good. No idea why, as the position was the same, and the hardware is no longer a variable. I’ve found this on other occasions, where it just seems to lose all performance randomly. Previously I was putting this down to hardware, but as I say, that’s now not an issue.

My wife’s HTC Desire just works flawlessly with great GPS reception. We’re in the UK and her gps.conf file is set to North America, so it just seems to work purely on hardware.

Could this be the radio? Do I need to mess around with gps.conf patches? It just seems that there is some sort of fundamental reason for this variable performance, but I’m struggling to get my head around what it might be.

I know this is a much discussed subject, and I’ve read a lot about it, but any tips would be greatly appreciated!

(I'm using Blackout ICS 3.0.0)

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[Desire HD General] recolor-shrink-spool:
Really strange sometimes I get about 11 sattelites, but still no fix! Does anyone know how is this possible and how can it be fixed?
[Desire HD General] joooe:
Apparently there's more to it than only antenna problems.

Check:

http://xdaforums.com/showthread.php?t=1862300
[Desire HD General] Komorias:
i will try this for sure.great job
[Desire HD General] RogerL:
This all sounds very familiar!

Not great, but at least I'm not alone. Thinking about it, after a reboot GPS is always 100% - as in my post when I started the phone after completing the mod.

As in the link, once it has a fix its pretty good at keeping it. However, turn GPS off and then back on and more often than not it doesn't re-fix. Apart from that, performance is quite random.

Anyone else experiencing this? Does anyone have any insight into what causes it, and what might fix it?

Maybe its a fundamental bug with certain batches of the dhd, cos its clear that this is not a universal issue.
[Desire HD General] PDub11:
Ill be doing this lunch time today, luckily i have access to a laser welder to do it and some polyamide coated silver plated wire, 30awg. :)

Will post results later.
[Desire HD General] RogerL:
Just in case it’s of use, here’s a ‘rough’ schematic showing how I fitted the spring contacts:

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[Desire HD General] AgentCain:
Tried the shielding mod myself. Cant say that adding aluminum tape and grounding it helped much. In fact, at all. And its the same kind of tape I use to shield my electric guitar's electronics. It would be really stupid if this had anything to do with shielding, because that would only mean they dont even know what they were doing
[Desire HD General] RogerL:
Fair point. As I say, its hard to be absolutely sure whether or not this mod improved the situation for my GPS, but it did seem to, mainly in SNR levels. I get the feeling that there is some variation in DHD devices, especially as some users report the seemingly random total loss of GPS performance as in the post above by joooe, something which my DHD definitely suffers from. Reboot and its fine again. Its still a mystery as to why this is. Reading back through posts in this thread, its interesting that for some people the soldered wire mod as in the original post made a significant improvement, while for others, myself included, it resulted in zero signal. Anyone have any insight into why this might be?
[Desire HD General] AgentCain:
To tell you the truth, I have a 100% working DHD, no problems with wifi, cellular or GPS signal. But its in my profession's nature to try out hardware and software mods :p I believe that its part placebo effect, part reset AGPS data and part reinforcing the worn out contacts.

Cleaning the contacts of my second hand DHD, I removed a bit of dirt and spotted tiny holes on the contact area. So soldering a wire, placing strings etc all result in fixing this problem.

In general, shielding helps a lot, especially when the SNR is low. But, have in mind that part of the antenna is also the PCB (the wiring from the GPS module to the contacts is also calculated as part of the antenna) so if there is any kind of signal noise, it should affect the GPS signal, regardless of shielding.

IMO what would be really helpfull is the kind of cover that Apple uses. The cover being the antenna. That would mean opening a hole on the plastic cover like a horseshoe and placing a piece of aluminum (oxidized) as the antenna. More robust construction (wont snap like these gold tape traces) and much better signal level.
[Desire HD General] RogerL:
Might just try that! I now have a couple of spare covers, so will try creating an alternative antenna. I have various bits of thin copper, aluminium and brass plate which I can use. Would no doubt be more robust than the thin gold strip embedded in plastic. If fitted carefully to the outside surface, it could be painted black and made reasonably discreet - rather than looking like a hatchet job. Shouldn't be too difficult, and at least worth a try methinks. Might not resolve all issues, but worth a try.

Out of interest, what would be the best metal to use - other than gold that is?
[Desire HD General] AgentCain:
Something that doesn't corrode over time. Gold of course is the best but lets be realists. I think aluminium is your best bet over copper and brass (which is also part copper) since it forms a protective layer of oxide asap. You could also used stainless steel, although its harder to work with.
[Desire HD General] RogerL:
Tried a rough go at this, and decided it wasn't really a go'er. The original antenna I think is actually ok. When GPS decides to work, it works well with quick fixes and reasonable signal strength. I've come to the conclusion that I'm one of those unlucky enough to have a dodgy DHD. Seems that people's experiences with GPS on this device varies greatly, from perfect performance all the time, to patchy performance like mine, to zero performance. It'd be great if there was some sort of fix. Performance has been reported to vary between ROMS, so software does play a part.

I'm at least satisfied that I've tried everything I can to boost performance, but that solving this fundamental issue is beyond me. I may try experimenting with different ROMS.
[Desire HD General] michaelopolis:
gps

Downgrading google maps to an earlier version seemed to help my gps problems a fair bit.
[Desire HD General] montyjosh:
pls tell me copper wire or alluminum wire
[Desire HD General] montyjosh:
last night at ten o clock with indian standard time i use this trick..and every thing is fine before doing this desire hd never gave me any signal indoor & two for outdoor but after this i gave me 5 signal indoor and 10 to outdoor..but now in morning the old same story happened no singal indoor and two signal outdoor..then i check the wire again its seems to be ok..the question is does GPS signal increase in night time..thanks in advance & sorry for my bad english
[Desire HD General] krzych:
No, it doesn't, but it strongly depends on the weather, and usually at night the weather is clearer ;) (because of the temperature probably), so yes, you could have different results then.
[Desire HD General] montyjosh:
i think this hardware trick fried my gps now my device show no gps signal what ever i am outdoor..no gps signal after waiting hours and hours..before this hardware trick my desire hd gave me 5 to 6 signal outdoor now nothing happened..pls someone help me
[Desire HD General] RogerL:
You may not have fried your GPS.

I tried the soldered wire option and lost all GPS performance, so I reverted to using the standard antenna/LED cover and GPS performance returned. I've tried all sorts and have come to the conclusion that the supplied antenna is actually pretty good provided the connection to the mobo is good. I tried using short lengths of soldered wire from mobo connections to the antenna, which worked when the cover was not attached, but killed the signal when the cover was re-fitted. So I ended up soldering small coil springs to the mobo connections and that has helped, but only when combined with applying solder to the antenna contacts. I think the springs will prevent the connection from deteriorating over time as with the standard contacts. It's a bit of a hassle doing all this though, and risky, so tread carefully if soldering. The contacts on the GPS cover melt away easily, so using a low power soldering iron is essential. I also managed to break one of the original mobo spring contacts, so had to solder directly onto the mobo, which wasn't easy and is risky.
[Desire HD General] aljazirrr:
Agps

Dont go this metod ,dont know last weak y have other rom and the gps was working great
[Desire HD General] the_unlocker1997:
Will this work on jellytime:)
[Desire HD General] EmptyArea:
In all honestly it's this and a number of other build quality issues that have put me off htc. Although I love this phone now I'm on my 3rd warranty replacement. I suppose as I'll always buy from a reputable source, with physical stores, I don't have to worry. Indecently I recommend CPW they did not bat an eyelid when my prox sensor was broken (one of the first batch if you recall?), then later my volume + stopped working and then later still my GPS would not find a fix.

As I say I've loved her, she's better than ever on jellybean, she switches on - goes to home - shows open apps - glides through menus screens - better than my gfs SGIII. But htc did not ensure the build quality was high enough to get my money again anytime soon.

Shame, they had potential to kill that pseudo Apple spinoff Samsung. Now that challenge rests on the shoulders of Asus, LG or Motorola.
[Desire HD General] tuner2000:
hmm now after testing various radios i must say that GPS is no longer a problem for me. with the newest radio i get GPS signal much faster than my navigation device. this is enough for me :)
[Desire HD General] brom66an6:
Is it possible that a bad cover could cause your phone not to turn on? I was getting ready to do this mod and took the back cover off but had to go somewhere so I put the cover back on but now the phone wont turn back on. Is it possible that the cover could cause this or is it just a bad coincidence? I noticed the contacts on the cover had some black marks and I tried to scrape them a little bit. thanks for any reply
[Desire HD General] RogerL:
The contacts on the battery cover seem to have the role of isolating the battery when the cover is removed. So if these contacts don't connect properly when the cover is replaced, there's no power getting to the phone. I wouldn't scrape the contacts on the cover if you can see black marks. That's the plastic underneath. The metal is super thin, so leave well alone. Light cleaning with alcohol should be ok though e.g. isopropyl alcohol - IPA, or tape head cleaner. You could also try very carefully bending the corresponding contacts on the body of the phone up slightly which should improve the connection. Be careful not to bend too much though and risk snapping them.
[Desire HD General] brom66an6:
Thank you for the reply. When I check the gps cover with a voltmeter should there be continuity between the two contacts on the cover? im asking because my cover doesn't have continuity between the contacts so I'm wondering if the cover is fried which is causing no power even if its making good contact on the board which it appears to be now.
[Desire HD General] RogerL:
Yes there should be continuity across the two gold contacts of the GPS / led cover. You can buy replacement covers on eBay for about £5.
[Desire HD General] brom66an6:
ok thank you I really appreciate it.
[Desire HD General] krzych:
I can remove both covers and phone still works, do not disinform people around.
[Desire HD General] RogerL:
The cover I was referring to was the battery cover. On my phone if that is removed it isolates the power. I have to admit I was presuming that is true for all DHDs. If that is not true then I apologise for posting misleading information.
[Desire HD General] markus123456:
Wow Thats great! Thanks man...:D
[Desire HD General] krzych:
No need for apology. Battery is just "touching" it's connectors, so if you remove the cover, it's not "pushing" it anymore to preserve the connection. But if you do it slowly, carefully, phone still works. Just do not wave your phone too much while removing :D
[Desire HD General] gabi_cameleonul:
great job
[Desire HD General] JVL1EN:
Endless story

Over the last months, I tried several ways to fix my phone's GPS reception quality and had mild success.

It all began when I "crushed" my phone in my pocket during a ride on a rollercoaster. After looking over this forum, I removed the the flash/antenna cap to investigate and noticed the contactors on the motherboard were bent. I put them back straight and the GPS was working flawlessly again.

Then I crushed the phone again, once, then twice and the contactors ended up completely broken the last time I tried to put them back straight.

At this point, I had no GPS reception at all. Then I stumbled upon this topic and tried soldering a home-made antenna, just like the author did. Tried first with a piece of speaker cable (copper). It worked, but the signal was poor and got even worse when I put the cap back. I then tried with a piece of rigid copper from a TV antenna cable, thinking it would work better.. it didn't.

My last attempt was with a thin wire froma USB cable and it works quite good, but not as well as it was when I bought the phone, especially when using google navigation which seems to need a very clean signal.

Now the contactors on the motherboard are worn out and almost no metal remains on it so my next and final attempt will be to replace the piece of motherboard on which the contactors are plus a new cap. These can be found over the web for quite a cheap price.

I'll post the results here when it's done to tell you if it's worth the investment.
[Desire HD General] RogerL:
Good luck with the mod. Is there not enough of the mobo connections to solder anything to it? Just that I found myself in a similar-ish position but managed to solder coil springs to the mobo which did the trick.
[Desire HD General] namhtc:
Great thread !!! I've just bought a pre-owned HTC Desire HD which works like a charm except for the GPS Signal ... but thanks to this thread it's the past.

How I fixed it ? I removed the GPS Cover/Antenna with a pair of scissors (I was on a business travel :laugh:) and I've just cleaned and twisted the electrical contactors and now EVERYTHING IS PERFECT :good::good:.

Last thing to do : try to upgrade my DHD to an ICS ROM :D.
[Desire HD General] JVL1EN:
I'm far from being an expert in soldering stuff and before that, I never imagined I would ever solder anything in my smartphone ;)

Actually there's almost no metal left on what used to be the contactors and I think that's what prevent me from having a strong signal. I guess it's the consequence of several soldering and un-soldering attemps that worn the contactors out. Also, the metal layer on the contactors, both on the motherboard and on the cover side is extremely thin if you look closely at it.

So in my case, I guess replacing the motherboard part is the right move. I plan to order this next month and post results then.
[Desire HD General] Pop Tarantula:
I had GPS problems and tried all known software solutions & the fix from #1 without much success. After watching the engineers disassembly video, I got inspired & have just replaced the Flex Volume PCB & flash/antenna cover. It didn't make a great deal of difference TBH.

Everything works brilliantly until I replace the back housing. Then it's like I've put it in a lead box at the bottom of the ocean :(

After much head scratching, I've considered that the GPS coaxial cable could be faulty & have now ordered a replacement.

Meanwhile, I've taken the OP to the extreme and instead of attaching a small wire loop to the connectors, I've split the coax and run a line (.5 solid) from the battery compartment divider plate up to the top and back, making sure not to foul up the vibrator mechanism or battery contacts along the way. Having a 3" aerial inside the case may not look pretty but once you close up its out of sight & it does the job.

Forgot to take photos, so I'll do that & update when I split again (to test new coax cable)
[Desire HD General] lukie1980:
GPS FIX

Took GPS cover off with ease and connected some old speaker wire round the springs by twisting it round with some tweasers , gone from 0 sats to 8 fixes in the house , I have GPS at last :laugh:
[Desire HD General] michaelopolis:
great,, pic please :)
[Desire HD General] lukie1980:
Desire HD GPS HARDWARE FIX

I'm going to make a video of the hole process :silly:
[Desire HD General] rakesh2002:
A misinformed post

This is to the creator of post: my apologies for being a critic, but for the betterment of knowledge sharing. In fact you might spoil your own desire HD using this technique.

Hello friends,

This post is not valid for one major reason:

The positive and negative ports cannot be shorted in the first place. that might build up heat depending upon the usage of the GPS receiver since voltage is shorted and hence no potential difference which might damage the GPS module.

The reason for this technique to work is due to the fact that the current incurred due to reception is extremely small and the wire used to short the terminal acts as a resistor with considerably high resistance thus not causing much of problem to the module. However, if it was a small single string cable then it will pose great threat to the circuitry.

Now, the reason why the OP was successful in getting GPS connection in 2 sec is not because of the wire, it is because of the solder iron which will establish a firmer contact with the casing when closed. gracefully the cable used to short is considerably big one for the low power microelectronic circuits.

There is no reason for the OP to be disappointed reading my reply since it is knowledge, the truth which no one is liable for.after all we are part of the XDA brotherhood. I have already posted an article on this long time back and I have clearly mention about the technicalities behind the working of GPS (http://xdaforums.com/showthread.php?t=1101066).

Please educate me if I am wrong. Thanks

-Rakesh
[Desire HD General] littleluke79:
I had some GPS issues and no apps, nothing helped. I was thinking about using this method but i did not know how to open the cover without leaving any sign and gave up

and then once, going out of the toilet, after looong news reading :P i was trying to open the door holding my DHD and

i droped it...

it fell on the floor covered by tiles with such a speed, that i thought there is nothing left of my DHD.

fortunately it did not break, there is just a corner that lost its colour a bit.

Anyway, you can't believe the GPS fix speed now:)

and it sounds funny, but it's true :) Shall I suggest to drop your DHD?
[Desire HD General] Vict20:
Rakesh

Nothing is being shorted out here, it's merely an antenna. A piece of looped wire that is a short circuit at DC can have a very high impedance at, for example the 1.5 gigahertz frequency of gps. At these frequencies, manufacturers have to be very careful with component and pcb track placement. A poor connection to the gps antenna can upset the whole sensitivity of the receiver which people here have been trying to improve.
[Desire HD General] rakesh2002:
lesson learnt

The GPS receiver is a Dual-Frequency type (two antennas tap in two frequencies of different wavelength)

check out this pdf "http://nemry.net/MultiAntennaGNSSAttitude.pdf", based on the paper, dual frequency measurement is used to achieve a robust and quick validation of integer ambiguities, if the two frequencies are L1 and L2, then L2 has a longer wavelength which improves fix performance: L2 basically improves integer ambiguity resolution process(pushing the throttle towards achieving greater SNR) while L1 has shorter wavelength hence lessens the multi-path delay. an algorithm is used to calculate output based on averaging of L1 and L2. this is given in detail in the paper.

So, shorting of the two terminals would mean that only one frequency, and thus one wavelength, is passed through both the antennas which would change the entire working of the circuit: which would not make sense at all.

To establish a faster connection, it is necessary to establish a rigid connection between the PCB terminals and the antenna of the casing, that's it. The above paper explanation is fantastic if you are interested in communication systems.

My previous reply gave right conclusion with partially incorrect reason(until the contact issue is brought up). This paper opened my eyes and speaks for itself of what makes sense and what doesn't.

Thanks,
[Desire HD General] jmg81:
i try this mod. Have sometimes poor GPS Signal strength. I hope it will find some more satellites.