So this is unexpected and thankfully I have a second reader due to my many orders over the years.
The read range of the first KBR1 unit I purchased in 2019/2020 has severely diminished. The only modification I made initially was to remove the buzzer but this didn’t affect anything over the past 1-2 years I have been using it to login. Today it stopped working and I was freaking out that something had happened to my implant but luckily I kept my cool and tested another reader first. I was wondering if anyone else has experienced this same issue?
I have a second KBR1 that I received earlier this year I believe and it reads like I expect it to. I opened up the reader I am having issues with and the antennae does read the chip without the housing in the way so I am at a slight loss as to why it shopped working from yesterday to today when it stays taped underneath my desk.
Unfortunately it sounds like a tuning capacitor might have been slowly going out of spec. If the performance slowly got worse and worse over time, that’s just what it sounds like to me. How’s the temperature in the room where the kbr1 sits? Does it fluctuate a lot by chance? Does it get really hot?
I never noticed any issues over the past few months although I have been travelling more so I probably wouldn’t have noticed if it was gradual.
I would say for maybe a year it was in my last apartment and I would put the max temp around the 90’s at the highest (accounting for when I was not there).
For the past year it has been in my office and the temps usually do not get past the 80’s (nest thermostat kicks in on the weekends if it gets too hot due to servers in a separate room).
hmm… well, regardless of the relatively stable temperatures it kinda sounds to me like a capacitor went out of spec on the board. The inductance of the antenna won’t change over time really, but capacitors involve a bit more chemistry magic and bad parts can cause detuning. Since you are able to still get a read when making contact with the antenna, I would guess the tuning has gone way off target… still enough to work, but not have any range really. I don’t know if there is a simple fix here.
Understood. Not much can be done for it but I did want to see if this was a common thing which it seems that it is not. Just going to make a few modifications and keep using it until it finally crosses over.
I don’t own a KBR1 so I looked it up the tear down pictures on the forum. I’ve never heard of a MLCCs drifting over time like that. Maybe it has something to do with cracks and moisture absorption? I doubt it’s the flux residue absorbing water but this can happen with the water wash stuff.
Not denying the possibility but the unit is taped under my desk/table in both locations I have utilized it. There are no holes near the unit for water to pass through and come into contact. Any water absorption would have been from condensation due to heat build up. I do not believe anything has been spilled on the unit.
Cable is also not the issue. I used the same cable with my second KBR1 and it worked flawlessly.
Normally yes but this is not our design or assembly work… it’s Chinese… anything is possible. Shit I once saw a delivery of counterfeit ICs from China for a military product be nothing but white PVC plastic potted in abs and then they went through reflow soldering it melted out and caused a fire in the oven.
