820-00923 Only Works After SMC Reset

brunomotter

Member
Hello. I got this one here with very strange behaviour... Machine was not turning on. I reseted the SMC and machine worked perfectly for some days. Gave it back to costumer, after some days she brought it back to me with same problem. After replacing the battery machine worked for a whole week. Gave it back to costumer again. Some days after she brought it back again with same issue. Now, if I turn the machine off and let it off for a minute or so it won't turn on again until I reset SMC. If I reset SMC machine will power on and work perfectly until next time I turn it off. This is very strange... Any ideas where to look? Board has no corrosion, very clean, no signs of liquid anywhere.
 

brunomotter

Member
HALL_SENSOR_RIGHT (Pin1 R5261) = 3.42V
HALL_SENSOR_LEFT (Pin1 R5251) = 3.42V

U5255:

Pin 1: 3.42V (Measured on Pin 2 of R5261)
Pin 2: 3.42V (Measured on Pin 2 of R5251)
Pin 3 = 0V
Pin 4 = 3.42V (Measured on Pin 1 of R5255)
Pin 5 = Unconnected
Pin 6 = 3.42V (Measured on Pin 1 of C5255)
 
Top