hello friends, I have a DELL LATITUDE 5420---MODEL P137G, ST 20TFKN3 LA-K491P REV:2.0 (A01) and its quite a challenge. It powers on with the battery disconnected, lasts on for about 15 secs, and then shuts off. It does the same with battery only (no adapter). With battery and adapter it sometimes starts after hitting the button several times. It displays nothing in every case. Since only the Boardview is available, I guided myself with schematics similar to this laptop (I'll add them down).Some measurements:
1- After receiving power SIO_SLP_S0# goes high and never changes.
2-every signal I checked BEFORE pressing the power button seems to be ok (except for 1)
3-after pressing pwrbtn EC sends SIO_PWRBTN# to the PCH, but after that SIO_SLP_S5# , SIO_SLP_S4# , SIO_SLP_S3# never go high (tested this signals even with a scope, nothing)
Tried several bios to see if there's any change, no luck.
Any hints are welcome, thanks in advance.
here's the boardview:
https://www.badcaps.net/filedata/fetch?id=3510122
LA-K034P schematic - https://www.badcaps.net/forum/troubl...en-11-la-k034p
19817-1 schematic - https://www.badcaps.net/forum/troubl...uthpeak-13-tgl
EDIT: I dont know if this laptop is one that needs the battery connected to boot, not that it matters I think...
1- After receiving power SIO_SLP_S0# goes high and never changes.
2-every signal I checked BEFORE pressing the power button seems to be ok (except for 1)
3-after pressing pwrbtn EC sends SIO_PWRBTN# to the PCH, but after that SIO_SLP_S5# , SIO_SLP_S4# , SIO_SLP_S3# never go high (tested this signals even with a scope, nothing)
Tried several bios to see if there's any change, no luck.
Any hints are welcome, thanks in advance.
here's the boardview:
https://www.badcaps.net/filedata/fetch?id=3510122
LA-K034P schematic - https://www.badcaps.net/forum/troubl...en-11-la-k034p
19817-1 schematic - https://www.badcaps.net/forum/troubl...uthpeak-13-tgl
EDIT: I dont know if this laptop is one that needs the battery connected to boot, not that it matters I think...