820-2838 won`t power up

[Glenn]

Thank you dukefawks. I will tray to remove r7252.

 

[Glenn]

I removed r7252 and nothing happens :/

 

[dukefawks]

I asked what happened to P3V3S5_EN. Is it still 1,56V?

 

[Glenn]

I asked what happened to P3V3S5_EN. Is it still 1,56V?

Sorry was was little too fast to answer. On p3v3s5_en i get 3.4V now. So then i have to replace the u7201?
Could i buy this on ebay?

Thaks for your comment louis im tray to ask what my shelf whay people whant me to too tings and tray to figure it out on the pdf file but all that is new for me have never seen a schematic befor in my life

 

[dukefawks]

Replace U7201 and put the resistor back.

 

[Glenn]

Thanks for all help. Will tray to replace U7201 and the resistor. This's U7201 is not programmed so i can replace it with a new from ebay? I have no donor board.

 

[Glenn]

is it this one i need to replace R7252 http://no.farnell.com/kemet/t520b157m006ate045/tantalum-capacitor-150uf6-3v-0/dp/2125175
and can i use this one to replace u7201 http://www.ebay.com/itm/2x-Texas-Ins...YAAOSwT5tWJ2Nz

Thanks

 

[dukefawks]

Buy some scrap boards so you have more parts.

 

[Glenn]

Thanks for the tips dukefawks

 

[Glenn]

...................

 

[Glenn]

Ok have now replaced the u7201 hopefully it's ok. But when I put the magsafe in it smoked from PPBUS_G3H and the shit is got burned ? Maby I was too fast to putt the magsafe in after alcohol cleaning?

 

[Glenn]

in diode mode i get 1,696 on P3V3S5_DRVH. thats mean i have a short on it? then i mabye something went wrong when replacing the u7201?

 

[Glenn]

Ok all fine with the u7201 and i have replaced the Q7260.

Now when i put the magsafe in the C7755 get very hot and i get 0.001 in diode mode so maybe this is brooken too? Ore maby the problem is u1400??

 

[dukefawks]

This all does not sound very good Do you even have PP3V3_S5 now from U7201? If C7755 gets hot it will be dead, replace it.

 

[Glenn]

I think that I have destroyed the entire motherboard .. removed u 7201 again last night and now I have many a points on u7201 giving me O L. nothing get hot and nothing starts up now. possible has a possibility I can not even fathom U7201.. mabye i heat the U7201 to mutch?

 

[dukefawks]

Powering it up without U7201 may also cause everything to fry. Without U7201 there is nothing to control the FETS and they can pass full PPBUS voltage to 3V or 5V bus. This thing is now fucked.

 

[Glenn]

Ok so the board is just for parts now?

 

[dukefawks]

I have no more ideas on this one, it died, smoked and who knows what is all wrong with it now. Smokified trash pile I think.

 

[Glenn]

Ok close case