Thread: eTrex Vista Cx won't power on - Repair ideas?

Originally Posted by Magnetron

Make sure is all back together as if you didn't take it apart.
Then contact Garmin and see if they do exchanges on this unit, is the quickest and easy way to get another unit

I did get a response from Garmin, they offered a 20% credit off MSRP of a new device to do an exchange. Not a bad deal but the unit I'll likely get (eTrex 30x) can be purchased for much less elsewhere. Oh well, I think got my money's worth out of the Vista Cx over the last 10+ years. I've been thinking about replacing it the last couple years but it's been working fine...I guess now I don't have an excuse!

So good news! Someone on another forum mentioned that the internal button cell battery might need to be 3V, not 1.5V, and after some digging around the web I found that to be true. I de-soldered the battery and soldered on a couple leads that I could use for testing by applying 3V with another battery. I assembled the unit and installed the AA batteries, but before applying 3V to the leads I tried to turn the unit on. Surprisingly the unit turned on! But I am really puzzled how this is possible without the 3V button cell installed, as everything I read said without it the unit wouldn't turn on. There is a reason the button cell is there so I'm definitely replacing it, but I'm curious why the thing turned on without it.

I also measured the button cell again after removing it and it was around 0.5V. I'm not sure how I got 1.5V before, but I'm guessing it was a residual charge since I initially measured it shortly after removing the AA batteries.

The button cell only had markings "68 f+" which didn't seem to help me. I found a page about replacing this battery and the person mentions part number ML621-TZ1-D, so I'll probably just go with that. It's a 3V lithium cell and the only difference may come from the capacity. The ML621-TZ1-D has a 5.8 mAh capacity. [Only registered and activated users can see links. ]

I also still have my Etrex.

Never had any problems with it.
I use rechargeable batteries and they last my over 12 to 15 hours.

The power button is very well protected from and water getting into it.

The Etrex is in use at least once a month as I do a lot of hiking in Europe.

Originally Posted by Magnetron

@ jstluise good find on that problem.
The internal battery is for the volatile memory "do you still have all your wpt & plts "??

I do still have my track log and saved tracks, as well as waypoints that were saved. Plts? I think most of what is stored in volatile memory has to do with the GPS information. It took some time for it to get a GPS fix, but I didn't time it and I'm not sure how long it normally takes. I shut off the unit, without removing the main batteries, and turned it on 10 minutes later and it got a lock fairly quickly, so it looks like the main batteries do keep the volatile memory. I'd have to do some more experimenting to really see what is held in volatile memory but at this point I'm just going to replace the battery and call it good!

A little more info on the battery in case anyone else runs across this thread in the future. The battery I pulled out of my unit has a diameter of 6.8mm and overall thickness of 1.74mm, which is more in line with a ML614 battery rather than a ML621 which has an overall thickness of around 2.65mm. The only difference between the two batteries, besides the thickness, is the capacity. The ML614 has a capacity of 3.4mAh where the ML621 has a capacity of 5.8mAh. Both will work since there is plenty of room inside the case for the extra thickness of the ML621. The ML621 will just last longer when the main batteries are removed/dead.