820-2530 ppbus .19 volts always stays green

[shanenin]

I do have a good ppbus of 12.61. I did before for a few minutes last time, but it did not last and d7010 burned out.

 

[2informaticos]

So D7010 is burnt again???
Really strange, as you got correct PPBUS_G3H.
Change C7010 too...

 

[shanenin]

I am sorry for being unclear. My oversized D7010 is still good and I still have a good ppbus. I was trying to say, whatever caused d7010 to burn out twice, will it happen a third time? What has changed?

 

[2informaticos]

D7010 was burnt because of U7000, pretty sure.
Change C7010 just in case...

Is the board working now?

 

[shanenin]

now I lost ppbus, or it is .4 volts :-( This time d7010 is still good. I wonder if I shorted something on u7000 by checking voltages on some of the other pins(just curious). I will get more info later for you. Thanks for all of the help.

 

[shanenin]

I now have 22.5 ohm between 17 and 18 and still have 20.4 ohm between 27 and 28. May I ask what you were checking for when you asked for these?

these are the new voltages on the isl pins:
2 18.5v
3 4.4v
19 0.2v
20 0.2v
12 3.4v
1 18.6v
14,9,15 all have 0v

I also have short on 19 and 20, is that the issue?

 

[2informaticos]

"19 0.2v
20 0.2v
------------
I also have short on 19 and 20, is that the issue?"
For sure...
If both pins have short to ground, bad ISL6259.
When remove it, check for any short to ground before solder another one.
Change R7040, probably burnt now.

"now have 22.5 ohm between 17 and 18 and still have 20.4 ohm between 27 and 28"
All correct there.

 

[shanenin]

after pulling off the ISL, the only shorts are 6 and 22, but I think they are both grounds and normal. I am hesitant to put another one on as something is frying it. The board came to me with a bad d7010. I replaced it and I had ppbus for a few minutes then d7010 fried again. I then replaced that diode with a stronger(I am assuming) one, then my ISL fried. I am guessing whatever was frying the d7010 was what fried the ISL since this time the d7010 did not act as a fuse.

I do have the original ISL I pulled. I suspect it may have been good, since d7010 probably protected it. Before I put it back on, what might be damaging the circuit?

this is an isl 6258, I noticed Rossman does not sell this one and I am out of new donors

 

[2informaticos]

Is true, that is ISL6258.
D7010 gets burnt because of U7000, not viceversa.

"2 18.5v"
A bit higher the input voltage.
Are you using bench power supply, or fake chinese charger?
16V should be normal voltage for original 60W charger.
However, original 85W charger shouldn't burn anything...

 

[shanenin]

It is a cheap one I have used for years. I will throw it away. I have only been buying genuine ones since I started following Rossman videos. Assuming the charger is not what fried it, could other things be doing it?

 

[2informaticos]

If you get correct voltage at F7000, shouldn't have other reason.
However, check Q7020 and C7025.

 

[shanenin]

I am still waiting on my ISLs to ship. Just curious, my oversized replacement for d7010 only drops 4/100ths of a volt, 18.50 to 18.46, is that normal? I was expecting more like 4/10ths of a volt drop. Could this cause any issues?

also will any ISL6258AHRTZ work? I see some have a second group of letters besides this main listing

 

[shanenin]

I replaced both d7010 and u7000 and I do now have a good ppbus of 12.6. For what it is worth, the charger always stays green and does not go to orange.

I do not have any voltage on pm_slp_s4

I was looking at u7750 and some stuff does not seem right. I would expect 1volt on both pins 2 and 3, but I have 3.4 volts on both, is that suspect? I have only .8 volts on pin 6.

 

[2informaticos]

Wrong assumptions.
Do you get 1.05V at C7771?
If not, change that cap...

PM_SLP_S4_L should go high when press power button.

 

[shanenin]

why would I not assume based on the names P1V05_S5_EN would be 1.05 volts and P1V05_S5_PGOOD is also 1.05 volts? I am asking to try and learn and understand

 

[shanenin]

PM_SLP_S4_L should go high when press power button.

when I start it by attaching the magsafe it is not pulsing.

I think I have checked all of my s5 rails, but this older board seems different than I am used to and it does not seem to have many listed in the schematic

 

[2informaticos]

MCP platforms never start when charger is plugged in; another wrong assumption.
Only iCore boards start this way.

"why would I not assume based on the names"
Just for that; pay atention to ENTIRE name.
EN and PGOOD mean something; they are signals, not power rails...

 

[shanenin]

Thanks for taking the time to explain these things. I did know they were signals, but I see my mistake. The name was referring to the power rail it started, not the voltage of the signal.

I attached a wire to pin5 of the keyboard connector and tapped the other side to ground to mimic pressing the button, but I am not getting any pulse on pm_slp_s4. Was that a correct way of starting the system?

Could I also short smc_onoff_l to start it?

 

[2informaticos]

Solder a wire on SMC_ONOFF_L line and touch the ground (momentary).

"Do you get 1.05V at C7771?
If not, change that cap..."
Can we get a reply?

 

[shanenin]

we do have 1.05v at c7771. I was looking for a clock chip and realized that is part of the MCPs job. I did check for a frequency at rtc_clk32k_xtalin and out and I get an erratic reading between 31 and 36mhz (jumping)

I am not getting any pulse on pm_slp_l when touching smc_onoff_l to ground