SOny MBX-216 3.3V lost

[tomodachi]

No any short, liquid spill or drop. This unit generates 3.3V (on pwr button) but when power button pressed it goes and to recover it I have to keep it unplugged for a while.
EC bios flashed but no change, checked all mosfets and capacitors to the ground, can't find any short or open please give me some suggestions.

[tomodachi]

Re: SOny MBX-216 3.3V lost

any suggestions ?

[tomodachi]

Re: SOny MBX-216 3.3V lost

some assistance please

[learnix]

Re: SOny MBX-216 3.3V lost

please drill down further , are you facing this when battery is connected ? or you are testing with only power adapter ?

have you tried using only battery or power adapter to identify the behavior ?

[lord]

Re: SOny MBX-216 3.3V lost

What do you have on pin 23 on the WPC775L after you press the power button?
Do you have voltage on the power button?

[atsio]

Re: SOny MBX-216 3.3V lost

First check resistance to ground on all coils. What are the voltages on pins 123, 96, 25, 26, 27, 108, 93, 23, 19 and 11 of U18?
The best way to check voltage strength in situations like this is with an oscilloscope due to poor sampling rate of DMM.

[whaldsz]

Re: SOny MBX-216 3.3V lost

what do you get at pin 20, pin 15 and pin 123 of SIO before and after pressing the power button?

[tomodachi]

Re: SOny MBX-216 3.3V lost

please drill down further , are you facing this when battery is connected ? or you are testing with only power adapter ?

have you tried using only battery or power adapter to identify the behavior ?

With or without battery issue is same. I m using a lab type power supply.
when I connect psu to motherboard I read 0.01 ampers then I press power button and amper indicator drops to zero and 3.3V gets lost from power button.

What do you have on pin 23 on the WPC775L after you press the power button?
Do you have voltage on the power button?

Sorry I can't measure those pins because daughter board blocks it when plugged. but there is 3.3V at power button before pressed. when pressed it goes to 0.
See; Without daughter board

with daughter board

First check resistance to ground on all coils. What are the voltages on pins 123, 96, 25, 26, 27, 108, 93, 23, 19 and 11 of U18?
The best way to check voltage strength in situations like this is with an oscilloscope due to poor sampling rate of DMM.

there is no short in all coils, I m pretty sure about that. and as I said above I can't measure voltages of SIO

what do you get at pin 20, pin 15 and pin 123 of SIO before and after pressing the power button?

[atsio]

Re: SOny MBX-216 3.3V lost

You can check all the signals on other smt components on the board. I.E. PM_SLP_S3# on R318 and D19, SUSON on PQ17, PR119, pin 3 of U56, etc.
Just follow the schematic.

[con55]

Re: SOny MBX-216 3.3V lost

First check resistance to ground on all coils. What are the voltages on pins 123, 96, 25, 26, 27, 108, 93, 23, 19 and 11 of U18?
The best way to check voltage strength in situations like this is with an oscilloscope due to poor sampling rate of DMM.

Hello

What is a good measure from the coil to ground? and when do i know when there is a short from the coil to ground?

[sebuncle]

Re: SOny MBX-216 3.3V lost

Hi
i have similar problem do you solved the problem ?

[mahmoodjavan]

Re: SOny MBX-216 3.3V lost

no any short, liquid spill or drop. This unit generates 3.3v (on pwr button) but when power button pressed it goes and to recover it i have to keep it unplugged for a while.
Ec bios flashed but no change, checked all mosfets and capacitors to the ground, can't find any short or open please give me some suggestions.

bios