Toshiba daby3cmb8e0 turn off at 7 or 8 seconds

[ruletero]

Hi all

Sorry for my bad English, this is my first post and I have a little skills in Laptop repairment but I have been reading a lot of threads to learn.

Well, I have a MB daby3cmb8e0 https://drive.google.com/file/d/1VHJ...ew?usp=sharing

Initialiy the Laptop did not turn on, I found short in 5v alws line. I changed PU2, PQ5007 and PQ5009, also I removed u5023 because it was faulty and the short dissapear, but...

Now, the Motherboard turn on but turn off at 7 or 8 seconds, no image in that time.

I suspect I have another short in the same line (5v alws) because resistence in PL2 to ground shows 60 ohms.

The question: That resistence is correct? What can I check now please.

Very very thanks.

Raul

[Techtiger]

Re: Toshiba daby3cmb8e0 turn off at 7 or 8 seconds

For the +5V S5 PL2 60 Ohms is low does your USB get +5V volts? Pc46
get leak some times 220u 6.3v remove it out and check the resistance on PL2
Test PU2 pin 23
You have to check all the Gary Coils Voltages
page 43 to 45 and 47 schematic all Big Gary Coils
example +VCCSA +VTT + VGPU CORE

[ruletero]

Re: Toshiba daby3cmb8e0 turn off at 7 or 8 seconds

I changed pc46 because had resistence, now PL2 has 275 ohms. I connected the coil and next I turned on the Mobo but It turned off seconds after. Now I have PQ5007 and PQ5009 shorted again.

PL2 connected measure: 156 ohms, I don't guess it is short.
I injected 1v at PL2 and no current consume.

I don't know what to do, what I should check before change the mosfets? help please.

[Techtiger]

Re: Toshiba daby3cmb8e0 turn off at 7 or 8 seconds

Remove both Fetes out of the Mob and test Diode mode PQ5007 and PQ5009
After test PC37 PC38 Caps Resentence
test PR36 PC48 also

[ruletero]

Re: Toshiba daby3cmb8e0 turn off at 7 or 8 seconds

PQ5007 and PQ5009 was removed and are shorted,
PC37 and PC38 not has resistence.
PR36 and PC48 does not exist in this mobo.

Now I suspect the issue is in the supply side but I can't understand where.

[ruletero]

Re: Toshiba daby3cmb8e0 turn off at 7 or 8 seconds

I changed pq5007, pq5009 and RT8223P again.. now turn on power led but I don't have 5v_s5, neither 3v_s5, only LDO voltages.

Sorry, I was doing something bad.. I have 3 volts at power button and I get 5v_S5 / 3v_S5 when the mobo turn on.. and again turn off at 7 seconds.

What thing I must to check now? please.

[ruletero]

Re: Toshiba daby3cmb8e0 turn off at 7 or 8 seconds

Today I checked and I have +VCCSA +VTT but VC CORE and VGPU are missing. Im checking why

[Udemzy]

Re: Toshiba daby3cmb8e0 turn off at 7 or 8 seconds

First of all check if your standby output and input coil of 3.3v and 5v line is fine with oscilloscope.

Then check your DC to DC section is passing. Don't forget to check if your slp_s3#, SLP_S4# and other suspens voltage is coming from sio.

[ruletero]

Re: Toshiba daby3cmb8e0 turn off at 7 or 8 seconds

Sorry but I don't have oscilloscope :/.

I'll check SIO signals. Thanks

[anshad]

Re: Toshiba daby3cmb8e0 turn off at 7 or 8 seconds

Today I checked and I have +VCCSA +VTT but VC CORE and VGPU are missing. Im checking why

How do you fixed the on-off issue ?. What was causing that ?

[ruletero]

Re: Toshiba daby3cmb8e0 turn off at 7 or 8 seconds

Sorry, I didn't fix the laptop yet, really I don't know what to do.

I connected an amperimeter and turn on, the consume was 0.08 A, very low. Either way the mobo turn off seven seconds later then I don't guess it has a short in a secondary supply, first I need to find why it does that.