Hi fellow tinkers,
Here is the problem as I see it,
I have a Compaq CQ56 which starts ok on battery but not from psu.
Checked the ISL6251 pin 24 DCIN voltage was not present.
Found 20V (psu voltage) on PQ2 (IMD2 dual transistor) pin 1.
Tried replacing PQ2 with a similar component from an old dv6000 motherboard. To be honest I am not sure the replacement component is ok either.
Point is I believe ISL6251 pin 24 DCIN should be approx 19v (adapter voltage) but I don't get that, it's approx 1v at the moment.
Can anyone shed any light on how these charger ICs work and what the IMD2 component does, or, if they often fail ? I was also wondering about the significance of pins 19 CSIP and 20 CSIN.
Pic of schematic attached hopefully.
Thanks guys,
Here is the problem as I see it,
I have a Compaq CQ56 which starts ok on battery but not from psu.
Checked the ISL6251 pin 24 DCIN voltage was not present.
Found 20V (psu voltage) on PQ2 (IMD2 dual transistor) pin 1.
Tried replacing PQ2 with a similar component from an old dv6000 motherboard. To be honest I am not sure the replacement component is ok either.
Point is I believe ISL6251 pin 24 DCIN should be approx 19v (adapter voltage) but I don't get that, it's approx 1v at the moment.
Can anyone shed any light on how these charger ICs work and what the IMD2 component does, or, if they often fail ? I was also wondering about the significance of pins 19 CSIP and 20 CSIN.
Pic of schematic attached hopefully.
Thanks guys,
Attached Files
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