X10 Community Forum

💬General Category => General Discussion => Topic started by: bkenobi on March 08, 2018, 12:43:43 AM

Title: (non-X10) Trouble shoot a RF device
Post by: bkenobi on March 08, 2018, 12:43:43 AM
I have a pair of Garmin GPS collars for my dogs.  One of them stopped working recently.  I contacted Garmin and they told me that they no longer support that model and that I would have to buy a newer model.  I realize that it likely the case, but since the collar costs $250 (maybe a little cheaper if I look hard), it seems worth my while to see if there's something obvious I can try to repair it.  I've looked at the board and see no obvious signs of damage and there was no water incursion that I could detect, so I'm not sure what to check.  The battery tests good.

If anyone has any thoughts, please chime in.  If I can't repair it, it's not a huge loss as it's currently unusable and basically worthless anyway.

Garmin DC40
https://fccid.io/IPH-01748
Title: Re: (non-X10) Trouble shoot a RF device
Post by: petera on March 08, 2018, 01:17:57 AM
Is there anything blocking the transmitter. Is there any chance the unit got wet at any stage seeing it is being worn by a dog. Do you need to recalibrate it after a battery change. If there's any chance it absorbed moisture gently heat it with a hair dryer.

Btw how old is the unit.
Title: Re: (non-X10) Trouble shoot a RF device
Post by: Knightrider on March 08, 2018, 01:40:25 AM
Post pic of board.
Title: Re: (non-X10) Trouble shoot a RF device
Post by: bkenobi on March 08, 2018, 01:42:42 AM
Just a little about the actual problem if anyone is interested:

The collar won't turn on and the charge light won't turn on when on the charger.  This is identical to the following video:
https://www.youtube.com/watch?v=r4-qFtJeum0
and forum discussion:
http://forums.ukcdogs.com/showthread.php?threadid=475249

But, the collar is an older version that Garmin no longer supports.  I was thinking that if it was an issue with a solder joint, then I could get an air reflow gun/station (like I discussed in another thread here...this was the reason I was considering it) and just slowly go over the whole board.  Otherwise, I'd have to locate a likely bad component which for SMD would be tricky due to size I assume.
Title: Re: (non-X10) Trouble shoot a RF device
Post by: bkenobi on March 08, 2018, 01:46:02 AM
I'll get a pic this evening.  The board looks pristine but the antenna is a bit beat up (plastic is cracking).  I don't believe anything has gotten inside the unit based on the looks of the seals when I opened it up.

My first thought was it got wet but since that's not the case, I'm thinking it's either a calibration thing, bad component, bad solder/trace, etc.  The FCCID page shows a procedure for recalibrating the unit, but it's only possible at the factory.  That said, I don't think that's the issue since it should turn on when charging and it's not.
Title: Re: (non-X10) Trouble shoot a RF device
Post by: bkenobi on March 09, 2018, 12:38:36 AM
I wasn't able to get the board all the way out as the pin comnecting to the antenna doesn't want to release.  I don't know if it is supposed to come off or not and I didn't want to break it.

I have a picture that I'm trying to attach, but it keeps failing.
Title: Re: (non-X10) Trouble shoot a RF device
Post by: Tuicemen on March 09, 2018, 12:49:59 AM
I have a picture that I'm trying to attach, but it keeps failing.
You may have to resize it as there is a file size restriction on the forum.
Title: Re: (non-X10) Trouble shoot a RF device
Post by: bkenobi on March 09, 2018, 01:03:42 AM
I tried, but my phone was only happy going down to 5MP.  I'll try again.
Title: Re: (non-X10) Trouble shoot a RF device
Post by: Tuicemen on March 09, 2018, 01:05:20 AM
You may need to send it to your PC to resize and or zip it.
Title: Re: (non-X10) Trouble shoot a RF device
Post by: bkenobi on March 09, 2018, 01:06:27 AM
Board
Title: Re: (non-X10) Trouble shoot a RF device
Post by: Tuicemen on March 09, 2018, 01:09:16 AM
The board does show some signs of corrosion which may be shorting things out.
Have you tried cleaning the board to remove the corrosion?
Title: Re: (non-X10) Trouble shoot a RF device
Post by: bkenobi on March 09, 2018, 01:27:52 AM
I didn't see anything that looked like corrosion with naked eyes.  I noticed there's something going on below the SiRF chip.  How would I clean it up?  For leaking batteries/capacitors I use white vinegar.
Title: Re: (non-X10) Trouble shoot a RF device
Post by: Tuicemen on March 09, 2018, 01:32:56 AM
White vinegar may work, rubbing alcohol may be better.
Title: Re: (non-X10) Trouble shoot a RF device
Post by: bkenobi on March 09, 2018, 02:08:12 AM
ok, I'll give it a try.  On e clean, if it still doesnt work would touching each solder joint with a soldering iron (or reflow with air) be the next step?
Title: Re: (non-X10) Trouble shoot a RF device
Post by: Tuicemen on March 09, 2018, 02:16:47 AM
Let it dry well first then I'd re touch with the solder gun anyways (but that's me)
Title: Re: (non-X10) Trouble shoot a RF device
Post by: petera on March 09, 2018, 03:13:59 AM
You might want to check the white plug and it's corresponding connector on that board for clean connection. Also another area to check is the antenna connection to ensure the solder is good.
Title: Re: (non-X10) Trouble shoot a RF device
Post by: bkenobi on March 09, 2018, 11:58:13 PM
I removed the board from the housing (had to desolder the antenna from the metal stud).  Once clear, I removed the tape whatnot as well as the metal shroud that covers the GPS components (I assume).  I cleaned both sides with white vinegar and a tooth brush and then with water.  There was minimal reaction to the vinegar which could have been from manufacturing.

I located the 5v/ground connectors that are fed from the charge ports and fed them 5v and ground from my bench PSU.  I was expecting the charge LED to turn on, but nothing happened.

The main chip appears to be an ATMEL MEGA32L but of course I have no way to debug it.  Interesting that this thing is not much more advanced than an Arduino with a couple radios and custom code.
Title: Re: (non-X10) Trouble shoot a RF device
Post by: dave w on March 10, 2018, 12:01:45 AM
See if you can follow the traces from the charging port or the battery pack to a regulator chip and check for output there
Title: Re: (non-X10) Trouble shoot a RF device
Post by: bkenobi on March 10, 2018, 12:14:31 AM
I'll see if I can locate one.  the white connector pin 1 is ground and pin 2 is +5v (left to right).
Title: Re: (non-X10) Trouble shoot a RF device
Post by: bkenobi on March 10, 2018, 12:23:24 AM
When looking at the pictures, I did notice one area of the PCB that looks scorched next to a 6 legged DIP.  I don't know what it does or if that's normal for this board though.  I don't see anything on the opposite side, so I assume it's related to heat on that chip.
Title: Re: (non-X10) Trouble shoot a RF device
Post by: bkenobi on April 04, 2018, 09:13:54 AM
When inspecting closely through a zoomed picture on my phone, I can see damage to the SMD.  Any idea what the 6 leg "731" IC might be?