Cricut Explore Air 2 Solid red light of death - Page 1
Forum section: electronics / repair

author: ali6x944
author_rank: Frequent Contributor
timestamp: May 03, 2025, 02:01:07 pm
content: Heydo everyone,I got this Cricut Explore Air 2 from my aunt last night and she said that it suddenly had a red light and refused to work.first I checked the power brick for the voltage and current, the brick is rated for18V@2.5A 45W out, the voltage was17.84Vat a test load of about0.18A, I connected it to the main board and measured the voltage and it didn't seem to budge, so the supply is most likely ok.I took the machine in and started to disassemble it and I was fairly successful in doing so, but looking at the main board there isn't a clear sign of fault, the board also passed the smell test, this is probably going to be interesting...some of these chips are giving me no real hits, especially the LF0362 and the FJ3091, I have seen athreadthat speculated that these chips are a some type of level shifter and a PIC24F? respectively.the voltage on pin 16 of the TPS60131 charge pump is4.979vwhich is within the tolerance of the converter, the voltage at 4954LPT between GND and VBB is17.30Vwhich looks about right, the LVC14A voltages look about right too3.287V...the part designators didn't give me much info, I am not sure how to proceed, watching videos on youtube I foundIdotoobyhe seems to be an expert and in hisvideohe speculates that the LF0362 might be the culprit, but I feel that the issue might not be with those elusive chips and more an issue with the power somewhere as the article onCricut.Helpalludes.I am again not sure how to tackle this so any suggestion is welcomed

author: ali6x944
author_rank: Frequent Contributor
timestamp: May 03, 2025, 02:09:29 pm
content: I forgot to add this in the original post but I also tried to connect it via usb and Bluetooth but it doesn't show up, also anotherthreadmentioned a forced firmware update mode that doesn't seem to work at all no matter how long I press and regardless of the button combination.

author: ali6x944
author_rank: Frequent Contributor
timestamp: May 13, 2025, 06:05:40 pm
content: heydo so I have done some investigations and here are what I found:the 3 pin SOT-23 packages are most probably as follows:(PD) BSS84 P-Channel Mosfet [confirmed the direction of body diode](72K) 2N7002K N-Channel Mosfet [confirmed the direction of body diode](H1A) MMBT3904 NPN BJT(05C) Unknown [when probed in diode mode positive to the center pin, negative to either side pins I get anywhere between 0.2-0.7v perhaps NPN BJT???](M21) Unknown [when probed in diode mode positive to the center and right most pins, negative to left most pin I get 0.9v perhaps PNP BJT???]the Bluetooth module is aRN-42Class 2 Bluetooth Module with EDR Support, the module didn't have voltage at VDD and0.969von /RESET so i bridged the VDD to a verified voltage rail compatible with module and reconnected everything and power cycled it and nothing changed, my guess is that the micro powers up the module via a GPIO pin? or via a high-side switch?? not really sure but it seems like its directly via GPIO.

author: ali6x944
author_rank: Frequent Contributor
timestamp: May 14, 2025, 04:38:32 am
content: I also investigated the headers on the board and i have a good feeling about the headers being for a PICkit style programmer, particularly header P101 and P301, if considering the square pad as pin one the orientation of the VDD and VSS pins and voltages seem to be correct. the pin count is also correct.can I use PICkit 3 to somehow ID the chip?