Sony VAIO vpcs111fm mbx 216 does not boot

[albin]

Hello,

My Sony Vaio VPCS111FM started to hesitate to turning on. In order to explain properly I uploaded a video on youtube. You can see at this link.

I tried power reset by removing power adapter and battery, but it did not help me to solve problem. For this reason I replaced its main board mbx-216, but unfortunately same problem struck again. I believe this main board has some design defects on itself.

In order to solve this issue I applied hot air on the main board, and it worked! Hot air solved this issue at least temporarily. You can see where I applied hot air on the main board below





I think there are some capacitor problems on this board.

Where should I look at? How to find defected component of this board?

P.S.: I probed U18 Pin 27 (VRON), it is synchronized with LED light of the power button. Simply EC cannot hold VRON pin logic high to enable PU1.

[albin]

Re: Sony VAIO vpcs111fm mbx 216 does not boot

I did more measurements today and I saw MAINON pin and VRON pin of the EC cannot be logic high to drive power controller chips.



Why WPCE775L (embedded controller) cannot hold high these pins to enable power for main board?
Also where can I find the datasheet of this EC?

[albin]

Re: Sony VAIO vpcs111fm mbx 216 does not boot

Any help on this topic?

[meritosari]

Re: Sony VAIO vpcs111fm mbx 216 does not boot

According from post#1, you gave heat on PU15, this IC to protect from adapter that over voltage, eg. 22V. then activate protection mode.
Make sure the Main Voltages already steady. (19V/3V/5V)

EC/KBC WPCE775 datasheet not available. Try compare with other scheme. but it's depending configuration from vendor. I think relate with "data" from ec bios.

[albin]

Re: Sony VAIO vpcs111fm mbx 216 does not boot

Hi meritosari,

Thanks for your response. I'll check the rail voltages (19V/5V/3V) with oscilloscope. You also mentioned "data" from EC bios(firmware). Do I need to update EC firmware? If so, can I load EC firmware with in-circuit interface (w/o removing the component EEPROM from main board)?

[meritosari]

Re: Sony VAIO vpcs111fm mbx 216 does not boot

I would prefer to read-write the chips after desoldering it out of the board.