backlights randomly turn off

[Hookemhorns111]

First time keyboard builder and I recently built the NovelKeys NK65 V2. My backlights randomly shut off and won't come back on unless I unplug the USB. Typing works fine, just not the backlight, randomly. Anyone have issues or know why or how to fix keeping my backlights on? I have made sure the cable is seated properly. Tested with 3 different cables. All the same outcome. PCB issue? Looking for insight.

[typo]

I will help you. You won't like the answer. However no one here likes me. You are correct. It is the PCB. Thank China. What has happened here technically is they managed to get the impedance(ohms) too high on the ground rail. This happens when there are a lot of junctions(solder joints) on a pcb that does not have a stable ground plane. It gets a stable ground plane with a good acid wash or laser imprint when the  pcb is made. The only thing you can really do, is if there are not too many bad traces. You can "jump" the pcb traces with very high gauge wire. You need to use a multimeter to see between which LED's there is much higher impedance than the rest.  Than "jump" between those LED's. It is very time consuming and imo not worth it. Learn a lesson and get another pcb. This is what happens with anything from China. LED's. Can last 65 years on these. I have never had a board last a year.  The reason it does not come back on is because the controller has "protection".

Now, of course I am assuming you assembled it correctly. If you caused some other issue it could have nothing to do with this. This is a typical production problem. Although I would say it only affects 1 in 20,000 pcb's. Bad luck there. The reason it happens after a while of use is because impedance is more or less a capacitor. It takes some time to store the energy before the controllers safety kicks in. I have had this several times and 40 other kinds of other failures. I no longer use back lit boards. I did not to begin with because they did not exist. I could do without them. More trouble than they are worth imo, I am a skilled touch typist. I do not need to see the board. I just thought it was cool. In the end was totally not worth it to me. I hope you can have some fun with one.

[Hookemhorns111]

That is way above my knowledge lol. It is a hot swappable PCB made/designed by yiancar for NovelKeys. All I had to do was drop my switches in and start typing. I was able to talk to yiancar about it and they aren't sure why it is happening. Another problem that began today is the keyboard would "eject" itself and then reconnect right away without touching anything. Then I went to open a new tab using CTRL + T, and the right ALT key was from that point indefinitely "pressed", even  when I take the switch out so no contact with the PCB points. Also the 9, O, L, , are all unresponsive. So it clearly is something deeper with the PCB and needs to be replaced.

[Leslieann]

Sounds like an intermittent short.
Talk to Novelekeys, they may as you to open it and see if anything is obvious, they may just send you a new one.

It's possible your usb is not providing enough power, try different ports not just cables, but my bet is that it's a pcb issue. My understanding is the pcb in these is actually one of the better made ones but defects do happen.

[typo]

I was not aware of any of this. Completely disregard what I said and RMA that thing. Or as Leslie said perhaps they might walk you through repairing it. That is highly unlikely. If neither pan out, you lost the lottery. I feel your pain then. It has only happened to me more times than I can count.

[Leslieann]

Worst case, unlike most companies they do sell replacement PCBs, yes it's more money but at least it would not be a total loss like with many other boards.