USB C PCB soft blinking light

[SGTgopher]

After having a complete G boy for about a week I noticed when I take it out of the case it is slightly warm. Only warm enough that you can tell it isn’t dead cold like a powered off device should get. Then I noticed that only in complete darkness I can see a faint greenish blue ish light quickly flash every half minute or so. This is with the GBoy completely powered off and unplugged. Is this common behavior? An issue perhaps? Seems like it would put an unnecessary strain on the battery

 

[Gman]

No doesnt sound normal. Check the wiring for any shorts or wrong wires.

 

[SGTgopher]

I re flowed all of the connections and cleaned it up, double checking my wiring was correct. The Gboy functions otherwise, and the slight warmth i was referring to is definitely from the USB board and nothing else. the blink is more accurately every 8-12 seconds. I dont see any way of capturing that on video though, it is incredibly faint. When I get back to my bench Ill try wiring it again and if it doesnt work, take some pics

 

[Gman]

I re flowed all of the connections and cleaned it up, double checking my wiring was correct. The Gboy functions otherwise, and the slight warmth i was referring to is definitely from the USB board and nothing else. the blink is more accurately every 8-12 seconds. I dont see any way of capturing that on video though, it is incredibly faint. When I get back to my bench Ill try wiring it again and if it doesnt work, take some pics

I experienced that once before however the problem turned out to be I hand assembled the PMS with the wrong PIC. These boards were assembled professionally so I highly doubt it is the same. I know what you mean though. The result is due to something keeping the PIC from going "to sleep" when the GBoy is powered off, likely wrong wiring with the USBC board producing some voltage difference on the CHRG wire I would guess, if there is voltage on CHRG, the PMS will not fully turn off.

The USBC board should not get warm at all. Check the connections and make sure VSYS, 5V, and GND are connected to the correct places. Pictures of the wiring might help.

 

[SGTgopher]

Ill get pics asap, but i do remember actually rewiring the 5v. in the manual, it mentioned wiring the 5V to the same set of resistors as the fan, which is how I had it configured originally at the beginning of this post, but i noticed those were labeled 3v3 and that the board revision is slightly different, so I went ahead and switched it to a pad clearly labeled 5v, though my understanding of the actual mechanisms at play here is very limited admittedly. The problem did not go away after this change either.

 

[Gman]

I dont understand how you wired it from the description, I'll wait for the pictures to say anything definitive

 

[SGTgopher]

I dont understand how you wired it from the description, I'll wait for the pictures to say anything definitive

Before, The yellow 5v from the USB C was going to the same bridged connection that the red fan power conductor is soldered to. All of my power and grounds are the same red wire but I double checked it’s all going to the right place. Figure I’d have worse issues if they weren’t. I took a pic before and after I soldered the ground so you can see the charge wire that’s usually hidden under it

 

[SGTgopher]

“Warm” is probably an overstatement. When it’s stuffed in the go pro foam case all night, you can just kind of tell the top portion where that board is is a degree or two higher than room temp.

 

[Gman]

This doesnt present confidence. All the wires have bit too much copper exposed after the joints. It's tricky managing it with the wrapping wire since it melts easily but it could be better. Then there is solder on the SDA wire where you connect the ground wire, not great.

Is that residue or burn mark on the U2 IC?

Also what happened to your usb drive?

 

[SGTgopher]

the state of the wires and their melted jackets is a result of all the recent work, so im not entirely sure thats going to solve it, but i suppose it wont hurt. the USB is a fitplus thats been stripped down to the necessary components for space reasons.

 

[SGTgopher]

and its residue, just came right off with an iso swab

 

[Gman]

The ground wire is routed over the led resistors, maybe try cleaning that up. In general the wires should not be routed directly over components there should atleast be a gap. So the wires on the usbc board could be tilted up a bit to be sure they arent shorting (which is why the solder on the wire can be an issue)

 

[SGTgopher]

This is probably the best I got in me without re routing new wires.

 

[SGTgopher]

After re routing and cleaning up ground a bit on the PMS, the issue persists

 

[Gman]

I dont see anything from what I can tell. If you want you are welcome to send them to me and I'll re rest them and see if there is infact an issue with the device itself (just the pcbs, not the whole gboy).

 

[SGTgopher]

The usb board and the pms? Ill probably take you up on that.
after I beat RE4 one more time