Dead MacBook Pro - No SMC reset and no charging

Hi this is related to a dead MBP (2010) which shows green light on charger and nothing else. I had earlier tried to locate the U7000 chip and measured voltages around that and had asked experts to help me on this. I have now managed to get a board view file and the circuit schematics. Here are some data that with 65W magsafe adpter connected

1. DCin board is ok with all voltages intact.

2. voltage after F6905 16.7 V going to pin-2 of U7000.

2. Q7080 status

pin-1 ,-2 & -3 : 16.7 V, pin-4: 15.52V and pin-5: 17.25V

3. Q7085 staus

pin-1,-2,& -3: 16.74V, pin-4: 11.38V, and pin-5:fluctuating (0-16.6V)

4. Q7030 status

pin-1,-2, &-3: 16.7 V, pin-4: 15.5V and Pin-5: 17.22 V

5. Q7055 looks like non-functional (voltages at all pins fluctuating betn 2.2 to 12.55 V

6. U7000 status

Pin-2: 16.76 V; pin-3: 2 V; pin-6 and -7: 3.42 V, pins-9,and -12 : 3.42V, pin-13: 3.4V;

pin-16: 0 to 5V , pin-17 and -18: 2.2V to 12.5V; pins-19 and -20: 5.1 V,

pin-23:2.2-12.6 V, pin-24: 4.73 to 14.7 V

I feel U7000 needs to be replaced so also Q7055. Experts, please suggest. Thanks.

Answered! View the answer I have this problem too

Is this a good question?

Score 0
Add a comment

2 Answers

Chosen Solution

Please don't give the individual pin voltages, give us voltages for the G3H power rails (PPBUS_G3H, PP3V42_G3H, etc) and S5 power rails. It will take too long for us to go through all of the pins you have said.

Fluctuation on dc in voltages is usually a nightmare to solve. Give a list of all the power rails and it will be easier for us to give you advice.

Was this answer helpful?

Score 0

Comments:

Hi Reece, thanks for your suggestion. After my initial failure of getting an answer, I had followed another discussion forum where it was suggested to measure voltages as mentioned in my last post. I will provide you what you have asked today.

Durga

by

Hi Reece, being not an electronics expert I have some problems regarding finding out the power rails. Looking at the circuit diagrams I have tried to measure PPBUS_G3H at F7040 which is 12.55V and 4.425 G3H at C6999 which is 3.42 V. But I have problem is locating S5 power rail. If you can tell me where to measure the rail voltage (I have the circuit schematics) I can possible do that. I have the following data as well. I don't know whether you can get anything from here.

1. PPVIN_S5_3V3S5 at C7291 fluctuates betn 2.1 and 12.55 V

2. PP3V3_S5_REG at C7253 (fluctuates betn 0.13 and 0.95V)

3. PP5V_S3__REG at C7293 0.V

4.PPVIN_S3_5VS3 at C7281, C7281,C7282 and C7272

(fluctuate betn 2 and 12.5 V)

All the above data were taken without battery connected.

With battery (no magsafe) PPVIN_S3_5VS3 at C7272 shows 10.83 V which goes to 12.55 with both magsafe and battery connected. Thanks.

by

Check PPDCIN_S5, this is probably causing the fluctuation on PP3V3_S5 and others.

If it is getting steady voltage, check out U7200 to see if it is shorted, or the caps are shorted around it.

Can't really give any more advice with this one without looking at it to be honest. If you have fluctuation on the DC in voltage, it will most likely be a nightmare to sort out, and I would just buy a new one unless something stands out as obviously bad. Listen for clicking on the board too, which usually indicates a bad MOSFET.

by

Thanks for your response. I finally could get to check the rails you suggested. Here are those.

PPBUS_G3H: 12.55 V (steady), PP5V_S3 is missing; PPDCIN_S5_S5: 17.22 V (steady); PP3V3_S3: missing; PP1V5R1V35_S3 is missing; PP3V42_G3H: 3.42 V (steady);

PP5V_S0 is 0.08 V (?), PP3V3_S0 is fluctuating between 2-12.5V (unsteady).

There is no fluctuation on the DC in voltage.

by

Yes, probably u7200 is shorted. Checked all capacitors around C7271,C7270, C7272, C7273 and C7260. They are all ok. I was trying to locate u7201 which in the schematics is shown to generate 5V and 3.3V power. But then realized that it U7201 as shown is a part of u7200 !

by

Show 1 more comment

Add a comment

I have an issue where batter doesn't get recognized, won't charge(no orange light). u7000 pin16 showing 12v leading to Q7055 pin4. Changed u7000 and Q7055 and checked the capacitors and resistors on that circuit. Do you think this is an issue between u7000 and SMC?

Was this answer helpful?

Score 0

Comments:

I had the same problem and thought u7000 to be faulty. In fact measured voltages at various pins of u7000 and few other chips. I was then suggested to try and check all voltage rails instead. In my case the following configuration was there.

PPBUS_G3H: 12.55 V (steady), PP5V_S3 missing; PPDCIN_S5_S5: 17.22 V (steady); PP3V3_S3: missing; PP1V5R1V35_S3 missing; PP3V42_G3H: 3.42 V (steady); PP5V_S0 is 0.08 V (?), PP3V3_S0 fluctuating between 2-12.5V (unsteady). There is no fluctuation on the DC in voltage. From here it appeared u7200 was shorted and may be u7000. I tend to agree with you that there is an issue between u7000 and SMC. I have just received u7000, 7200 and few other chips along with some other tools needed for smd soldering work to try my hands on this repair.

by

the problem i'm having is that the U7000 chip is showing 12v on pin 16. I think their is a resistor that has gone bad. is it true that a resistor will cut down the ppbus_g3h 12v to pp3v42?

by

I don't think that is correct. pp3v42 is generated by u6990.

by

Add a comment

Add your answer

Durga Mahapatra will be eternally grateful.
View Statistics:

Past 24 Hours: 0

Past 7 Days: 9

Past 30 Days: 43

All Time: 163