820-2850 Green light but no fan spin

[kevinklinkmuller]

Hi there!

I have an 820-2850 with Green light but no fan spin. It's measuring 0V at PP18V5_DCIN_FUSE

I'd really appreciate any help!

Thank you!

 

[kevinklinkmuller]

I'm guessing this has something to do with one wire

 

[dukefawks]

If there is really 0v there it must be a dead fuse, a short or a bad magsafe board

 

[kevinklinkmuller]

Very strange. it's now showing 16.8v at the fuse now. Could've sworn it was 0v .

But anyway, the issue is still there. Have green light but no fan spin and no boot

 

[kevinklinkmuller]

Also, have tested another DC in board with no luck.

 

[aprendiz]

PPBUS_G3H voltage?? PP3V3 present at L7260?? PP5V_S3 present at L7220??

 

[dukefawks]

Are you using a REAL GENUINE APPLE 85W charger?

 

[kevinklinkmuller]

PPBUS_G3H fluctuates what looks like between 3v and 12 volts. it goes up and down.
L7260 fluctuates as well, between 0v and 1v
L7220 is just 0v

Yes always genuine

 

[kevinklinkmuller]

I can try a fake one if that helps

 

[aprendiz]

Resistance between pins 17-18 and 27-28 from U7000, resistance on R7005........ Report values....

 

[kevinklinkmuller]

17-18 = 3.0
27-28 = 20.1
R7005 = 20.1 too

 

[kevinklinkmuller]

ohms, not mega ohms

 

[aprendiz]

Resistance to GND on PPBUS_G3H??

 

[dukefawks]

I suspect an issue around U7201. P3V3S5_EN pulsing high?

 

[kevinklinkmuller]

very impressive dukey doo, you magician!

Looks like crap there. Looks like burnt pins there too! Shall I just replace it all?

Thanks!

 

[kevinklinkmuller]

Ah, also, pin 6 is 0v

 

[larossmann]

Someone else has already messed with this so it will not be fun, you can tell from the TPS51125 being soldered on some pins and not on others. And the joints that were created without enough flux.

If you remove F7040 does PPBUS_G3H still pulse or no?

 

[dukefawks]

It's been messed with so nothing can be trusted there. Replace U7201 and measure resistors and traces.

 

[TCRScircuit]

Almost looks like the pads were RIPPED OFF

 

[kevinklinkmuller]

Thanks guys! I've finally received my donor boards for this model, will look into repairing this soon