Shock-Proof your Garmin GPS

Overview
Shock-Proof your Garmin GPS to prevent unintended power-downs. I look at a couple different ways to make the fix, and actually do one of them. This project requires soldering a couple of fairly tricky connections inside the otherwise working GPS, so use caution.

Background
I use my GPS a lot, mostly for biking. It's mounted on the handlebar no matter where i'm going - on-road, off-road, everywhere. problem is, after enough hard bounces something goes loose inside the unit and it shuts off. i had this problem a lot with my older Etrex, now i've got a 76cs which worked great for a few months but now has the same problem - enough hard bumps and it shuts off. once the unit shuts off the first time, it usually will do it again and again with very small bumps, so it ends up nearly useless.

Step 1 Tools & Parts

You'll need:

• a couple small screwdrivers (phillips and regular)
• a sharp knife
• some high-temp glue such as hot-melt glue or silicone
• fine-tip soldering iron
• capacitor: 470uF 4V or similar (i used digikey part# 495-2292-1)
• a little bit of flexible wire

You want to get a high-value capacitor but it needs to be small enough to fit in the GPS case - there isn't a lot of room. After I finished it seemed like i probably could have fit something a bit larger in, such as one of the smaller 1000u electrolytic capacitors measuring 6mm diameter x 12mm long. I used a 470uF tantalum which is smaller but more expensive.

Comments

[trivalleypro]

I have a garmin 60csx and it turns off while snowmobiling. How would you fix this, is it about the same as the other garmin let me know thanks.

[Wayne az]

You could fix the #1 vibrating open problem by using silver conductive epoxy. With screws and conductive epoxy, it would take a lot of abuse. The downside is it would be damaging to remove the board from the batteries again. I'm taking mine apart now because the battery clip flexed so many times it cracked at the "V" apex. If I had epoxied the unit together earlier, I could not do that.

[Godot]

Great Mod. I wonder if anyone from Garmin ever visits here. It would be great if they added the cap themselves before they sold them.

[dan]

i think it is partly a cost & size problem. a small-size large-cap part is expensive, and a large-size part won't fit easily.

[jolshefsky]

Nice Instructable; great pictures -- especially the macro ones. I did this for a thermometer/clock that I hated to reset every couple months -- I could just sneak by pulling out old batteries and popping in new ones. But from that experience, I'd also note that the capacitor will tend to discharge batteries left in it, so definitely remove batteries when you put away the GPS.

[blindmen]

I only say that your solution works, since my skills in electronic aren´t as good as i would like, instead 470uF i used 2x100uF and it works pretty well.

[djformi]

Any chance you can tell what type of screen is in the gps. I cracked mine and need a new one. I do not want open just yet. I see that it is a sharp by your pics. Any part number? Thanks

[nabt420]

Sweet mod! Way to improve a commercial item! Is physical size the only limitation on the cap that you used?

[dan]

pretty much. battery voltage max is 3V, so a 4V capacitor is fine. higher voltage cap means less capacitance in the same size, so you want the 4V or 6V caps. some caps (eg electrolytics) are rated by temperature also, probbaly stick with ones rated above 100degC.

[jeffcheesey]

Hello Dan I have this vibration problem with my garmin gps3 plus could i add a cap. to fix my problem? if so where would i make the connections? My set up is different then the etrex, my battery terminals are not the press fit type but are wired directly to the connector.

[dan]

i'd check if there is an existing capacitor across the battery (it would be near where the battery wires connect to the pcb). if not then add your own there.

[macfreak4]

Actually, two fresh AA alkaline batteries could scrape 4v -- a 6v or greater cap would be more on the safe side.

[Myself]

I love how the "VSUPERCAP" test point is clearly visible in the pictures. They're obviously already doing this for memory backup during battery changes, but apparently their capacitor doesn't keep the CPU running, just the memory/clock.