Since yesterday my L320 gets very hot (CC3200 Board; powered by power supply or battery).
I just put the cfw to the sd card and have played a bit with the setting of cfw (removed/inserted SD card several times).
I can’t find any visible defects.
Did anybody know this problem or have info about the components (DCDC, parts that uses the voltage of the dcdc,…)
It looks like the DCDC is the U320 and this is a 5V DCDC for supplying the RFID unit (source: toniebox-pcb/doc/blockdiagram.jpg at master · toniebox-reverse-engineering/toniebox-pcb · GitHub). I could therefore imagine that the original error was that I may have connected the RFID antenna to the 6-pin header in a different position (so that only three pins were connected). However, I have not yet found out what function the individual pins have and whether this could really be the cause or what could have broken.
On the thermal imaging camera you can also see that only the coil and possibly the DCDC get hot.
At the output cap C322 i can measure about 4V.
The antenna connector is half GND half +5?V or something similar to drive the antenna. Maybe you shorted the 5V this way?
This may help: GitHub - toniebox-reverse-engineering/toniebox-pcb: KiCad schematic of the Toniebox PCB (including datasheets).
There is still the possibility that I have caused a short circuit by connecting the antenna incorrectly. However, as the two opposite pins are connected to each other, I would have to have moved the connector sideways, which is hardly possible inside the housing.
Nevertheless, the 5V DCDC seems to be defective. From the switch pin to GND it is only 74 Ohm (after desoldering the DCDC there are about 51k Ohm.) - no wonder that the coil runs hot and the 5V is no longer reached.
Unfortunately I couldn’t find any information on Github about which DCDC is used here and my own research hasn’t turned up anything either.
Does anyone here have any ideas?
Check the data sheets of the chips powered by the dcdc. So maybe the RFID ic has an example circuit to implement it.
Unfortunately, I couldn’t find out which DCDC is installed as the U320. However, I was able to repair the Toniebox by replacing the following components:
