A1311 late 2009 820-2494A only 1 led non starting

ex250

New member
Hello, unsolded from a donor a D7301, values where different on diode, so changed it first

Results:

P1->3,36
P2->4,55
P3->1,078
P4->0,801
P5->5,09
P6->5,09
P7->5,09
P8->GND
P9->2,89
P10->5,09
P11->12,08
P12->9,98
P13->7,09
P14->5,09
P15->5,09
P16->1,25

But still not working led 2 of the board.
 

ex250

New member
L7320->5,08
L7460->0,01*
L7610->1,21
L7660->3,37
L7920->1,11

Seems that there is a problem at the L7460, likely u7401 related? what to check there?

Many thanks for all your help and guidance
 
Last edited:

2informaticos

Administrator
Staff member
Value looks good.
Check U7401 surrounding components.
If all good, change the chip.

BTW, any reason to quote an entire post, visible few centimeters above?
Write directly into reply box, instead of clicking Reply button...
 

ex250

New member
Just replaced the U7401, now the second light powers up, mounted the system, but powers, fan speeds up and power down again. No post error sounds, no "dong" sound and no screen powering up.
 

2informaticos

Administrator
Staff member
L7201/21/41 voltage appears?
Check ALL_SYS_PWRGD and PCIE_RESET_L, when fans spin.
You may need to test with other MXM graphics card.
 

ex250

New member
Tested with a functional CPU, still same. I started the board without CPU and there is 1.28v at the L7201/21/41

Seems that something shorts them with the CPU inside... Could inject that voltage to find any heating element, if there is any other, apart the cpu.

What do you think?
 
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