hp cq61,da00p8mb6d1 no power on

[lxlx4430]

Got a hp cq61,da00p8mb6d1
When I press the power button nothing happens.5v 3v is ok
I replaced the Isl power management controller chip Isl 6251 , rt8206, bios ,io and reflow southbridge still the same problem persists.please help

[killersoft]

Re: hp cq61,da00p8mb6d1 no power on

Got a hp cq61,da00p8mb6d1
When I press the power button nothing happens.5v 3v is ok
I replaced the Isl power management controller chip Isl 6251 , rt8206, bios ,io and reflow southbridge still the same problem persists.please help

I have the same model and the same problem I have the voltages 3v and 5v and the charger indicator lights up I do not see where the problem is located ?

[mcplslg123]

Re: hp cq61,da00p8mb6d1 no power on

Schematic is available. Why not check the basic requirements of SIO. Randomly heating here & there and replacing components will not help. You need to diagnose it and that requires patience(little bit understanding of schematic help).

[mon2]

Re: hp cq61,da00p8mb6d1 no power on

Post the voltage checks for the attached.

[killersoft]

Re: hp cq61,da00p8mb6d1 no power on

Post the voltage checks for the attached.

+VAD = 19V
+PRWSRC = 19v
+6251_VDD = 5V

[Umadbro]

Re: hp cq61,da00p8mb6d1 no power on

Hi. I have a "DA00P6MB6D0" motherboard which when plugged into the charger, the light would turn on and go off after 2~3 seconds. I managed to find a short on "PC114" capacitor, after lifting one side of "PL9" inductor to find which line had a short. So this is referent to "+3VPCU", or at least I thought so following the schematic.

I removed this capacitor, and without swapping for a different one (or testing voltage in this place after removal) I plugged the charger, and KB3926 burned, making a little spark and opening a fissure on the top of the ic.

After removing the IC, I measured the positive side of where "PC144" was soldered before, and I'm getting 19v. The same applies to pins "9;22;33;96;111;125;67" on the board where "KB3926" was soldered before. In the schematic, it says these lines are "+3VPCU".

I have a new "KB3926", so as a "330u 6.3v" electrolytic capacitor on their way, to solder back on this motherboard, but I am very sure I'm not getting the right voltage on the places referred above. I have doubts if "KB3926" was indeed faulty before and "C144" was preventing it from bursting (as it was shorted), or if it was the fact that I turned on the machine before replacing the capacitor that created the issue. It would be nice if someone could explain to me how this situation unrolled, as I have never had a situation where the voltage missing was actually being supplied the full load(???).

I also measured "TPS51427A" (PU2), and pin 25 has 19v. I cannot understand this, maybe I am not reading it right, but I think this is where the 3v power rail starts, and if so, something very wrong is going on here.

I attached the schematic I'm using so you can see what I'm seeing.

Any help will be very appreciated. Let me know of any more information I can provide.

[Umadbro]

Re: hp cq61,da00p8mb6d1 no power on

After removing "KB3926" and plugging the charger, the charger led indicator stays on solid white.


And just now I measured PL8 which connects to pin 10 of "TPS51427A", and it gave me 0.007v. I think this was meant to be 5v.

So on this ic where it should be creating 3v and 5v, it isn't. Please let me know if my line of thinking isn't correct.

[mcplslg123]

Re: hp cq61,da00p8mb6d1 no power on

Without kbc soldered on the mb, you wont have output on 3V/5V coil as the pwm(tps51427) needs enable signal to make output on these coils. You should have 3V/5V LDO without kbc soldered.