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November 6, 2008

Surgery on the Garmin Edge 305

Filed under: Google Earth,GPS,Howtos / tips / tricks,Tech Corner — mtbguru @ 8:23 am

I’ve been using my Garmin Edge 305 for over two years and am pretty happy with it. Unfortunately though, it seems just like with many other electronic gadgets these days, two years is about the time at which things start to fail. One doesn’t have to be entirely paranoid to assume that they may be just designed that way. Anyways, the first symptom was the device randomly shutting off during bumpy sections on my road bike – looked like a case of ‘battery bounce’. This got gradually worse and worse, to the point at which the slightest bump on my (suspended) mountain bike would kill it; it just wasn’t usable anymore. The thing was long past warranty and I didn’t feel like forking out Garmin’s $100 flat rate for repair – so it was time for some surgery. It’s always fun to try fix things yourself.

A quick round of Googling showed that I wasn’t the only one with this problem, and soon I ran into this helpful thread on one of the Motionbased forums, from which I came up with this plan of attack:

Open up the device; the case consists of two halves which are glued together. You basically have to pry open the rear black section from the front section. Important: a rubber strip runs along the side of the device and covers the switches; it has been molded onto the gray front part and is to be permanently attached to it. The seam which has to be pried open is between the rubber strip and the black rear part, NOT between the rubber and the gray front part. You can use your nails or a spatula, see the picture below (all the photos below are linked to higher resolution images btw, click on them to see these).

Garmin Edge fix1
The adhesive will slowly come off (and make a bit of a mess), a gap will open up and at some point you’ll be able to lift the black cover off. As usual with these things, don’t force it or you may break stuff.

With some patience, you’ll be able to separate the two halves.
Edge fix2
The random shutdown problem is most likely caused by the spring connector (the 8 gold coated pins on the bottom left of the top part, which contact gold coated pads on the bottom part, see image below). When the device is closed up, the leads of the battery (in the top half) run through this connector to the GPS board in the bottom half; the other contacts of the connector contact the mini USB port. The little springs (see pic below) only create a good electrical contact if they’re sufficiently compressed. Edge fix10
And that’s the heart of the problem: the compression of the springs is determined by the gap between the two halfs. The contact pads on the bottom half sit on a small piece of PCB, onto which the external USB port is directly mounted (see pic).
Edge fix3
A spacer underneath the small PCB defines the gap (see the profile shot below) and it is the adhesive force of the glue that holds the two parts together.
Edge fix4
So, after numerous cycles of plugging in and out a USB cable and applying significant forces on this piece of PCB, it is not hard to imagine that it can get somewhat wedged loose over time and as a result the compression of the springs decreases or fluctuates, something which only will be aggravated when you have the device mounted on your handlebar during a bumpy ride. The intermittent contact then leads to the device shutting down.
Basically, it’s a design error with respect to strain relief and could have been avoided by not having the USB port directly mounted onto the piece with the contact pads for the springs.

In order to fix the problem and make the connector more robust for a hopefully long future use I decided to combine two fixes mentioned in the Motionbased forum thread: hardwire the battery leads to the GPS board, and add a spacer to the small PCB with the USB port.
First though, you want to properly clean all contacting surfaces to make sure there’s no dirt or other contamination creating trouble – you can use for instance DeoxIT contact cleaner for this – check out the macro-photo I took of the connector tips: it’s easy to see that some dirt on those tips can become an issue.
Edgefix11
Detach the small PCB to expose the battery leads – it’s kept in place by two screws on the sides.
Next, solder a wire from each battery lead to the GPS board – this requires some care and a steady hand, but it isn’t that hard. A good type of wire to use here is magnet wire – thin, plastically deformable wire that has an insulating coating on it (and is typically used for coil spools). Because it keeps its shape when you deform it and the thin wire is very light, it won’t move around too much inside the device during use after you’ve closed it up again, and the solder joints shouldn’t come under any significant stress.
The picture below shows where I soldered the wires at the battery/USB connector side (and is also a testament of my sub-par but in this case sufficient soldering skills).

Soldering a wire from the battery leads to the board will pretty much eliminate the battery bounce effect during rides. But to ensure the contacts to the USB port (which you need to download data or recharge the battery) remain in good shape, the additional spacer comes in – this will basically compress the little springs a bit more and create a more robust electrical contact. I took a thin piece of rubber with adhesive on one side (the type you can buy to cut out for instance rubber feet to glue on small furniture or equipment) and cut out a piece that is pretty much identical in shape to the original spacer, then placed it on top of it.

Then put both spacers on the small PCB and screw it back in place. The picture below shows how it goes together. It also shows the contacts on the GPS board where you need to solder the other ends of the battery wires to (as always, be careful when doing this – you don’t want to smolder components or splash solder all over the place).
Edgefix8
The trick then is to nicely wrap the extra wires you’ve put in there alongside the board in such way that you avoid them touching the spring connector or getting squeezed when you flip the two halves of the device back together. Practice this a few times, because in the final step you’ll need to do it with glue on the case.

When you feel comfortable with this, it’s time to put new adhesive on (of course, you’ve already scraped the old one off as well as you could). I used some ‘Black Max’ Loctite (see picture) that I applied on the edges of the black rear cover – this adhesive works well with rubber and plastic.

Move both parts now gently together, making sure the wires sit nicely in place and out of the way and being extra careful with the area that contains the spring connector. When the two parts are locked back together, put a weight on the device (see picture) and let the adhesive cure. You want to use this weight and apply a uniform force in order to minimize any gap between the two parts (remember this affects the spring compression and also the operation of the Start/Stop and Lap buttons).
Fifteen minutes later, take off the weight and power on the GPS! Check whether the USB port works as well (you could also do this before applying the adhesive by clamping the halves together and gently plugging in the USB cable in the port.
If all went well, it will stay on, including during the roughest bumpiest rides you can find. (If it doesn’t power on, not all is lost: go back to start – the Loctite adhesive is removable just like the original adhesive). I’ve done this fix a few months ago, and my Edge was working almost like new again – and as to date, it still is.

54 Responses to “Surgery on the Garmin Edge 305”

  1. luiz Says:

    Hi , very nice job and tutorial….

    I have this device for 1 year and 6 months. the support from garmin asked me to buy another device for $99. I don´t want to pay it and I think I´ll have to make the surgery as well. Is it currently working now? Did you solve the problem or I need to throw it aging the wall ???? I have the same problem during my road trainning session the devide turn off. It becames often since last month.

    Regards
    Luiz

  2. mtbguru Says:

    Luiz, my Edge 305 is currently working indeed (this e.g. was one of the more recent things I recorded), 3 months after I did the fix.

    I would recommended testing everything thoroughly before you glue things back together (by e.g. having it clamped together temporarily) – this includes the on/off switch, the lap and start/stop buttons, the buttons on the right and the USB port connection.

    I had to redo the procedure because the start/stop button became very hard to operate – the ‘gap’ between the two halves determines how well this pressure sensitive switch works, and the single drawback of using the extra ‘spacer’ at the USB connector is that this gap increases a bit and hence makes the switch harder to operate. However, by cleaning the old glue thoroughly out of the seams of the casing, and by keeping the two halves properly pressed together during the curing/drying of the new glue, it should work. Good luck if you try it!

  3. greg Says:

    mtbguru,
    Thank you for the very complete tutorial. I am about to begin the process myself, but I am concerned about the type of glue that you chose. From what I have read, this glue tends to be permanently permanent. Have you tried re-opening your 305 after using the loctite glue?

    My problem seems to be slightly different than most. My 305 shuts off regularly on rides, but the terrain is not always bumpy. Sometimes it has died on perfectly smooth roads. More frustrating is that I cannot get the 305 to shut off at home. No amount of shaking or dropping will cause it to turn off. That is why I was thinking that I may need to open it up more than once, and I want to make sure the glue will allow me to do that.

    Thanks in advance for your help.
    -Greg

  4. mtbguru Says:

    Hi Greg,
    I did actually open it up more than once (first to solder the wires, later when I realized I needed to install the spacer) – the 380 Loctite can be removed in pretty much the same way as the original glue. How easy it is depends on how liberal you were when applying it…

  5. foo Says:

    you just saved me $89 and my wife thanks you as she was getting pretty fed up w/ her 305 shutting off 4-5 times a ride on the road and not so frequently on dirt. I’m trying the spacer mod first (as i cant find small enough gauge wires to solder yet) to see how that goes.

  6. mtbguru Says:

    foo,
    just be careful and patient – also don’t overdo the thickness of the spacer – and it should work.
    Not sure where you’re located but that type of wire can be cheaply bought at e.g. Fry’s (CA etc) or any electronic components store (or online at Digikey)…

  7. foo Says:

    thanks mtbguru, i managed to get it opened rather easily i found some foam pieces that were a few mm thick and works so far rather nicely. now the test to see how it works on the road.

  8. avelascoj_Mexico Says:

    Thanks you for the very complete tutorial. My garmin edge 305 shutdown frecuently, but now is repaired.

  9. Big Helmet Says:

    Yeah, that’s an amazing set of instructions. You’re a king for putting that up.

  10. Alex Says:

    Awesome tutorial! Thanks. BTW- for the spacer, I recommend cutting up any old tire tube.

  11. Scott Says:

    Thanks for the tutorial. While I have mine apart, I also need to fix the mode button. It broke after I dropped it and its rattling around in there. Do you know if this can be done or if anyone has a tutorial on how to do this?

  12. mtbguru Says:

    @Scott: not sure, but perhaps you may find these buttons/switches on e.g. digikey.com and replace the broken one…

    @Alex, good tip on the the spacer – a piece of tube would work well indeed

  13. Scott Says:

    I got the Mode button fixed. There were three pieces to the switch which just snap together. Once put back together, the button now works. However, Once I put the Garmin back together, the display was a lot darker. I can still read it but just barely. Anybody have any ideas?

  14. Scott Says:

    Somebody in another forum told me to try adusting the contrast. Thats what it was and now the display looks fine.

  15. mtbguru Says:

    Yes, I was thinking of that… ‘arrow up’ button…

  16. Ken Says:

    Excellent instructions. I just took the 305 out for a cross ride and no problem at all anymore. I used a bike tube for a spacer and the buttons need to be pushed a little harder, but well worth having the 305 working again. I would just add that the board comes out of the grey side (sorry for my lack of technolical lingo). When I realized this it made the solderin much easier. Thanks for this great fix!

  17. Dana Says:

    Your information rocks! Followed the procedures as outlined and took it out for one of my bumpy rides. Worked like a charm! Thanks for this information:-)

  18. Sam Says:

    Great instructions. I may have one better. I just got off the phone with Garmin and they have labeled this as a “known issue” and are now issuing replacement units for FREE. You must send them your unit first. They will give you a RA number and send one back.

  19. Gerard Says:

    Hi,
    Is the FREE unit replacement for the 305 warranty or any ?
    My Edge is 2006.
    Thanks

  20. Bill Says:

    Worked like a charm! Thanks for publishing this fix.

  21. George Says:

    Thanks for the great instructions. I took the actual battery leads and hardwired them to the circuit board. Used Duco silicone glue for the case… worked like a charm!

  22. greg Says:

    I repaired my 305 myself, and it didn’t go so well for me. I think I used too much glue, and as a result, elevation stopped working, and I couldn’t get the device apart again to fix it. On the plus side, it didn’t shut off anymore…

    So last week, I decided to bite the bullet and contacted Garmin to start the RMA process. As Sam said above, Garmin offered to fix my unit free, even though it is way out of warranty. Unfortunately, once I ‘fessed up to fixing it myself, I had to pay the $89 (which is still much better than the $150 that it was last year). The whole process took exactly one week, and my freshly re-manufactured 305 is in much better shape than the used beat up device that I sent them.

    Garmin indicated that they have re-engineered the power connection, so I am hoping the intermittent shutoff is gone for good.

    Moral of the story – DO NOT TAKE YOUR 305 APART. Call Garmin. Even though I am out $89, I am delighted with the outcome.
    -greg

  23. George Says:

    Greg, I think the real moral of your story is “don’t use too much glue!”

  24. Alan Says:

    mtbguru, when applying the Loctite, do you apply a bead around the entire rim of the black cover? I’m guessing you do, as it wouldn’t be entirely waterproof if it wasn’t. That being said, i’m also guessing that you apply only a thin bead, as too much will render it unopenable (as Greg demonstrated above!)

    I appreciate your site…this shut off thing has been killing me for the past year!

  25. Jonathan Says:

    This is a great resource. Ive got a similar problem but on the other side of the unit and a little bit different. I crashed the other day and cracked my screen. Does anyone know where I can get a replacement screen, or has anyone replaced the screen before, or have any idea how hard it would be?

  26. mtbguru Says:

    @Alan: yes on both questions. Though to be honest, I don’t think my new seal is really waterproof. Then I personally don’t care too much since where I live rain is pretty rare much of the year ;) . If you take a lot of care though I think you could make a pretty good seal.

    @Jonathan: my memory fails me in trying to remember how the LCD is hooked up. I think if you can get your hands on a new LCD (find a cheap broken unit with good screen on ebay?) you can probably replace it; though I’d guess you’d spend too much time and money on it than it’s probably worth…

  27. Neilswheel Says:

    I just put the spacer in. I wrapped it with some electrical tape and it seems to be working pretty well. It does seem strange that they engineered it this way. I was going to do the solders but dang they look pretty darn small.

  28. John Says:

    A great blog and helpful instructions and pics. Just taken my 305 apart and put in the extra spacer and all glued back together. Its now sealing nicely with a couple of zip ties and some weight on top. Will test ride in a couple days and hope all will be well…

  29. AfricanSingle Says:

    Brilliant. Top marks for your blog and the solution.

    HEADS UP GARMIN!!!!! ??HELLO GARMIN?? ANYBODY HOME!!!!

  30. Pete Says:

    My 305 would not switch on so assumed it was the battery as it would switch on with usb. Replaced the battery but still have the fault, followed your instructions to the letter, all connections are fine and double checked them. Any clues to the problem?

  31. Nick Says:

    Had a problem where I had too much salt from sweat build up under the front switches to where they stopped functioning. Flushing with a bit of alcohol restored operation. This would be a bad thing if the rubber membrane is torn.

    Haven’t had the power switch off problem yet, but when I do and open it up, I’ll use a tiny amount of LPS-1 lube which is thin film conductive on the contacts before reassembly.

  32. Michel Says:

    Just did surgery on mine and tested it. It solved the problem. THANKS A LOT.
    Only thing now is that the altimeter now doesn’t fonction any more. That,s a bummer but I can live with that.

    Michel

  33. woodrz Says:

    “Greg, I think the real moral of your story is “don’t use too much glue!”” ROFL!

    This is brilliant. I am currently waiting for Gramin to repsond to a query before goong down the DIY route. 2 days and no resonse makes me wonder if I’ve hit the wrong contact page on the website – does anyone have a contact email address for them in the UK?

  34. Mike Says:

    When I pulled my 205 apart, I also found that the little plastic nib(for lack of a better word) that aligns the top of the main board was broken off allowing the it to move inside the case. I suspect this is causing my shutdown issues.

  35. Dan Wilson Says:

    If you don’t want to attempt this yourself, I will do it cheap:

    Garmin Edge 205 305 Repair, Vibration , Button, Battery
    http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200472458117&ssPageName=STRK:MESELX:IT

  36. Peter Says:

    My Garmin EDGE 305 recently started the shut-down-thing. I was tempted buying the EDGE 800 but fortunately I found this website and decided to operate and it worked! Brilliant and thanks!

    Peter

  37. Richard Says:

    My Edge 205 would shut down on the bumpy ride over and over.
    I cut a small gasket from a tourniquet for under the contact strip.
    The 205 has not shut off since no matter how rough the road.
    A complete fix. Thank you.

  38. Sam Says:

    If you hardwire the battery, do you really need to change out the spacer?

  39. Rick Says:

    I don’t believe I have the loose connector problem (let’s hope not). I replaced the original 3.7V 800mAh battery (Garmin P/N 361-00025-00) of dimensions 6.6X48.45X39.4 mm (Thick X Length X Width)with a Fuji NP-45 3.7V 1500 mAh dimensions 5.7 X 30.6 X 30.4. So, its smaller with nearly twice the juice. The Edge 305 fit back together well and the battery doesn’t seem to shake around inside. The sticky backing was too big, so I folded it over at one end. I think that will help hold it down better. The Loctite 380 seems to be the ticket, as well. Thanks for the article. Let’s just hope my system doesn’t start re-setting on me.

  40. steve Says:

    The “glue” that holds the case together is clear silicone. It can be removed with a little work, get it ALL off, and re-glue with the same stuff. Use very small amounts, leave no gaps, and it will be waterproof again. Silicone does not dry quickly, so wrap it up tight with some rubber bands and give it 48 hrs to dry. Also note that if you do not remove the original adhesive your re-glue job will not adhere properly. Nothing sticks to silicone.

  41. Andrew Says:

    Thanks for the excellent instructions.
    I stumbled upon this as I was trying to find out how to open the 305. Your method worked a treat. I have a different issue with the display intermittently going very dim.
    Of particular note, and the reason for my post, is that Garmin seem to have recognised this power issue. When i opened my 305 unit i found that it already has power wired directly to the main GPS board. Mine was purchased around late 2010.

  42. Chad Says:

    Thanks! Another reason I love Google. Just typed in “Garmin 305 bumpy road” and got your site. Just got done doing the fixes you did and it works perfectly so far. Thanks so much for saving me money!

  43. Capt Slog Says:

    Thank you for your instructions. I’ve just completed the fix, but I went for the ‘battery only’ stitch of the two wires.

    I thought you might be interested to know that the Garmin305 I worked on (my son’s) had a little strip of rubber under the springs of the sprung contacts. This was around 1.5 wide and self adhesive, I had to remove a tiny piece at the end to expose the battery GND connection. I wonder if this is the ‘re-engineered solution’ mentioned in #22 above?

    I used silicone as the glue to stick the unit back together, the clear stuff you get for bathrooms etc. which smells of acetic acid.

    When I switched the unit on after the fix, the screen had all sorts of stuff on it which looked like factory set-up, and when I pressed some buttons it went into a weird pattern mode and wouldn’t do anything else! I thought I’d broken it, but it was ok the next time it was turned on.

    Cheers

  44. shmuel kish Says:

    dear tom
    27-5-13
    suddenly the Garmin stopped working.
    in my search i have found —you!!
    and it is amazing, i have followed your steps
    used a new thin Sony battery
    and after the work have been done i have a new long lasting 305!!!

    thank you very much.

    shmuel kish
    from Israel

  45. alsop Says:

    Very useful instruction. Was going to follow, but checked with Garmin first, just to see what was what. To my surprise, I was offered a free repair/replacement through the request a repair web page (even though my 305 must be at least 6 years old !?). It was shipped today so should find out what I’m getting in next few days. Anyway, not to detract from excellent advice above, just another option to consider.

  46. Bert Says:

    Thanks for the great tutorial! Due to the lack of a Soldering Iron I first tried the extra spacer cut out of a tire tube. . It seems to be working correctly again, although I still have to test it on really bumpy roads.

  47. john Says:

    alsop
    Thanks for the heads up. I just checked and I am also getting a free repair/replace 305.

    I would check here before opening up your units.

    https://my.garmin.com/rma/repair/repairLanding.htm

    John

  48. Dan Says:

    Please stop doing the “spacer repair.” I am getting lots of these after they fail again. The contacts just end up getting smashed down and the original problem returns. Only now all of the contacts are smashed and often just fall off when touched. The only way to permanently fix this is to install jumper wires for the power contacts. Do the wires not the spacer! Or just have me do it for you ;-)

    Dan@fixyourgps.com

  49. Mark Says:

    Thanks much for this tutorial. Per your wonderful instructions, I just hard wired the battery on my Garmin Edge 305 and replaced the original spacer with a somewhat thicker piece of rubber, and it works great now on the first test ride. Before, the power used to drop out several times during every ride, even on a smooth road.

  50. Rob Says:

    Just done this on a 305 myself, I actually found the screen wasn’t working which was due to a little ribbon connector underneath the screen, worth checking, I bet this works itself loose too!

  51. Alex Says:

    You have saved my day. My edge 205 is working reliable again.
    Thx for sharing this.

  52. Justin Says:

    Glad I read the comments! Was about to crack mine open and checked warranty. Garmin is replacing mine for FREE!

  53. Rob Says:

    I have 2 Edge 305′s with cracked screens. Anybody know where I can buy replacement screens for them?
    Thanks

  54. powman Says:

    I have a 305, and the battery ideas at a little over 1hr. is it possible to replace the battery with one from garmin edge 800 which has 1000mAh, which will possibly give it more runtime hours. however, the edge 800 has 3 wires coming out of it red, black and white as opposed to 2 from the 305. how can i wire the 305 using the 800′s battery. should I just ignore the third wire and solder away or theres another way to do it? thanks

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