No Power MacBook Pro 13" Mid 2009 820-2530-A

[Stephen]

Tested all points of PPBUSG3H is present. PP5V is present.
What is not present is PPV_S0_CPUVTT and MCPCORES0_IMON is not present etc. On the MCP VCORE POWER SUPPLY , PPVIN_S0_MCPCORE is present for all Caps C7563, C7560, C7571 etc. Resistors are good and visibly good as well. I am assuming the CPU is dead, I also replaced the SMC chip (assumed it was a bad SMC chip) and that didnt solve the problem. Anyone have an opinion?

[mon2]

Re: No Power MacBook Pro 13" Mid 2009 820-2530-A

U7600 is the voltage regulator for the CPU Vcore @ 1.062V (PPCPUVTT_S0_REG).

What is the voltage @ L7620, pin 2 ?

Also post the voltage into L7620 as per attached diagram.

Please reference the exact net names as per the original schematics so they can be quickly found through the PDF search feature.

If your 5 volt rail is present then U7600 should have the 5 volts as the input - please confirm.

[Stephen]

Re: No Power MacBook Pro 13" Mid 2009 820-2530-A

Damn fast replay mon2! Ok checking now

[Stephen]

Re: No Power MacBook Pro 13" Mid 2009 820-2530-A

0 volts present at L7620

[mon2]

Re: No Power MacBook Pro 13" Mid 2009 820-2530-A

Yeah, going cross-eyed in designing a new product. This new widget should assist in the repair of these logic boards.

Check and post the voltage on pin 10 of U7600 (PP5V_S0_CPUVTTS0) which should be 5v0.


Check and post the voltage on pin 1 of U7600 (CPUVTTS0_EN). This pin turns the switching regulator ON / OFF via this ENABLE pin. This is driven by a RC (resistor & capacitor) circuit - see attached.

[piernov]

Re: No Power MacBook Pro 13" Mid 2009 820-2530-A

https://www.badcaps.net/forum/showthread.php?t=88758

No power

• Check if DC-in jack LED lights up
• Check voltage on all the large inductors
• Follow power sequence if it exists in the schematics
• Follow list of power rails if it exists in the schematics

Note: don't forget to trigger power button when measuring for the rails that only come up when machine is turned on.

When requesting help, please attach a picture of the board with voltage and resistance to ground measurements on all the large inductors after triggering power button.

[Stephen]

Re: No Power MacBook Pro 13" Mid 2009 820-2530-A

Pin 10 = 0 Volts
Pin 1 = 0 Volts

Yeah, going cross-eyed in designing a new product. This new widget should assist in the repair of these logic boards.

Check and post the voltage on pin 10 of U7600 (PP5V_S0_CPUVTTS0) which should be 5v0.


Check and post the voltage on pin 1 of U7600 (CPUVTTS0_EN). This pin turns the switching regulator ON / OFF via this ENABLE pin. This is driven by a RC (resistor & capacitor) circuit - see attached.

[Stephen]

Re: No Power MacBook Pro 13" Mid 2009 820-2530-A

Also mon2, tested R7881 Resistor to see if it is blown or failed. I have 33K on the resistor so it shows good on the board. No power at cap C7881. RIP life lol

[mon2]

Re: No Power MacBook Pro 13" Mid 2009 820-2530-A

Wait , the cap could be fine. What is the voltage reading @ the junction in the attachment?

This whole cluster of resistor & caps are a poor-man's delay circuits to sequence the power rails. They really should have used voltage supervisors that once they reach a specific voltage threshold -> release the reset line and/or enable the next power rail, etc.

This power sequencing is done to prevent latch up conditions. In our opinion, rc circuits are not recommended but it is a cheap method that appears to be 'just ok'. We strictly use power supervisors in our designs. Never a fault.

Need to know if you have +voltage on PM_SLP_S3_L_BUF.

Then if this rail is zero volts here, keep checking 'to the left, to the left'

https://www.youtube.com/watch?v=2EwViQxSJJQ

[Stephen]

Re: No Power MacBook Pro 13" Mid 2009 820-2530-A

No voltage at all on PM_SLP_S3_L_BUF Going to check further

[Stephen]

Re: No Power MacBook Pro 13" Mid 2009 820-2530-A

I kept going to the left...LEAD to the damn CPU ROFL I KNEW IT.

[mon2]

Re: No Power MacBook Pro 13" Mid 2009 820-2530-A

I would suggest to review sheet # 3 of the schematics (K24 POWER SYSTEM ARCHITECTURE) and follow and record the order of the power rails (the order is inside each circle).

Perhaps you will find some other critical rail is missing which is leading to this demise.

[Stephen]

Re: No Power MacBook Pro 13" Mid 2009 820-2530-A

I guess you have a point. I will get back with you! Also just found a damn data recovery tool for this A1707 I been working on! WOOT we can save the customers data!