No the battery status does not work but I put that down to the cable which looks like it has been distrurbed and possibly damaged as others have reported earlier in the thread but maybe I have an issue with the SCL/SDA signaling. I cant locate these 6pin BMON chips U5403 and U5413 anywhere on the board especially seeing as the notes say they should be close to the SMC and resistor R7008. If anyone has a Landrex component board view file and can either send it to me or locate these suckers for me it would be much appreciated. I'm going to try to trace these SCL/SDA lines and see if there is anything wrong there.
Got a tip for us?
Let us know
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.
SMC Issue on MBP 13 - Hardware Troubleshooting Guide
- Thread starter Dadioh
- Start date
- Sort by reaction score
No the battery status does not work but I put that down to the cable which looks like it has been distrurbed and possibly damaged as others have reported earlier in the thread but maybe I have an issue with the SCL/SDA signaling. I cant locate these 6pin BMON chips U5403 and U5413 anywhere on the board especially seeing as the notes say they should be close to the SMC and resistor R7008. If anyone has a Landrex component board view file and can either send it to me or locate these suckers for me it would be much appreciated. I'm going to try to trace these SCL/SDA lines and see if there is anything wrong there.
Before replacing anything, I think you have an opportunity to check something else. You have the luxury of access to a known good Mac of the same vintage. On the good one, try this:
Try to power the system using battery power only with the battery status cable DISCONNECTED. If this works, then the problem is not the I2C communication and possibly the signaling I mentioned. If it doesn't power up, you better get a replacement status LED assembly for the nonb-functioning Mac before going any further.
Be careful with that tiny flex cable. It rips easily, and often times get pinched then torn by the battery mounting screw.
Last edited:
Great idea! The issue stayed with the logic board and the battery status worked fine with the good logic board.
After further analysis
=SMBUS_BATT_SCL is open circuit on the battery connector
=SMBUS_BATT_SDA has approx 6k ohm to GND which is what I have on my good logic board. So at least we have identified SCL line is the culprit.
I changed the input diode D6950 - no change
The resistance between pin 2 SMBUS_BATT_SDA and pin 3 SMBUS_BATT_SCL on the battery status connector is 1.4M ohm compared with 2K ohm on the good logic board.
I tried to find R5280 1k resistor and R5281 1k resistor on page 42 SMC "Battery A" SMBus Connections page but could not locate them but I suspect that must be my next check once I can find them but it is like trying to find a needle in a haystack as the schematic gives no clues other SMC pin k7 which is no help as it is a BGA chip and buried under the SMC itself!
I try again tomorrow but I think we are getting real close now thanks to all the help.
Wow !!!! great work.Were you able to get exact replacement for q6910?If so where,if not what is the replacement part & where can I get some?I can only order from Newarc Canada & they don't list it.Good luck Thanks
@papabear60: One other thing that may benefit myself as well as others are the physical locations (and prices/links to where to get these components) of the devices you have identified or replaced in this thread. I am thinking that if you can annotate a JPG pictures of the Macbook logic board you are working on and post it, we will be able to increase our knowledge on how to identify and replace these bad components. Currently, although I know how Q6910 is supposed to work, I have no idea where it is physically located.
Thanks.
Last edited:
@papabear60: One other thing that may benefit myself as well as others are the physical locations (and prices/links to where to get these components) of the devices you have identified or replaced in this thread. I am thinking that if you can annotate a JPG pictures of the Macbook logic board you are working on and post it, we will be able to increase our knowledge on how to identify and replace these bad components. Currently, although I know how Q6910 is supposed to work, I have no idea where it is physically located.
SUCCESS
After hours and hours of teadious searching and measuring resistances all over this damn logic board I found 2 resistors together one was 1k ohm and the other was open circuit and Voila ! Once replaced the battery status lights worked and the battery started charging so it was one of the pull up resistors that went open that caused it not to charge the battery. I noticed when trying to trace these suckers from the connectors and charging chip ISL 6258A that the two tracks always ran together so I started to look for 2 1k ohm resistors together anywhere on the board.
The schematic really helps because you can literally see if the tracks and components match what you are finding.
I have attached the original picture (which I cloned from an earlier response in Dadioh's thread) where I asked Dadioh what was the component that I had seen light up like a Christmas tree and he correctly identified it as the overvoltage circuit so I have attached it again here adding Q6915 and U6915 arrows and labels which we also replaced.
I am semi retired and enjoy messing around with these things on the side and got all my components from dead boards I have collected over previous failed "projects".
I will take a picture of the location of the two pull up resistors and post it - probably wont help much as it was probably a one-off issue but it took me so long to find them that if it helps one person then it will be worth it!
Thanks to all for the help and on to the next project.
Attachments
SUCCESS
After hours and hours of teadious searching and measuring resistances all over this damn logic board I found 2 resistors together one was 1k ohm and the other was open circuit and Voila ! Once replaced the battery status lights worked and the battery started charging so it was one of the pull up resistors that went open that caused it not to charge the battery. ...
I will take a picture of the location of the two pull up resistors and post it - probably wont help much as it was probably a one-off issue but it took me so long to find them that if it helps one person then it will be worth it!
Thanks to all for the help and on to the next project.
Congratulations. Looking forward to find out where the 2 resistors are located for future reference and that could be very soon. I just acquired from eBay a water damaged MacBook A1181 early 2008 and it will not power up. Have not begun opening it up yet, however when plugging the magsafe, I get green light but nothing else. Upon removing the SODIMMs I noticed that the SODIMMs connector traces have white residue on it.
Good sleuthing Papabear
Just to let you know I haven't fallen off the edge of the earth... just really busy. But I do check in here often to see how things are going. I have a bunch of logic boards to work on lately and just haven't gotten the time to spend on it.
My latest acquisition is a MBP 15" unibody 2.8GHz that I picked up off eBay with water damage. Charges the battery all right but otherwise dead. Checked the secondary fuse that feeds the 12V to the whole board (PPBUS_G3H) and it was open. GREAT I thought. Easy fix. So I threw an 8A sloblow fuse on there and things started getting hot. 1V was being fed to the processor even though I had not told the board to start up. The Inductor on the battery charger circuit was getting quite hot so I measured the output voltage and it was something like 2.5V!!! Quickly removed power and checked the impedance to ground after the fuse and measured 12ohms. Yikes. So that is why the original fuse blew.
So now I need to try and figure out what component hanging off of PPBUS_G3H is shorted to ground. I would have expected it to be a toasty bit of carbon by now but I guess if it is a FET it can withstand a fair bit of current. One thought that I had was to apply the power and then run around the board with my infrared thermometer and find the hot spot. Any other ideas?
Just to let you know I haven't fallen off the edge of the earth... just really busy. But I do check in here often to see how things are going. I have a bunch of logic boards to work on lately and just haven't gotten the time to spend on it.
My latest acquisition is a MBP 15" unibody 2.8GHz that I picked up off eBay with water damage. Charges the battery all right but otherwise dead. Checked the secondary fuse that feeds the 12V to the whole board (PPBUS_G3H) and it was open. GREAT I thought. Easy fix. So I threw an 8A sloblow fuse on there and things started getting hot. 1V was being fed to the processor even though I had not told the board to start up. The Inductor on the battery charger circuit was getting quite hot so I measured the output voltage and it was something like 2.5V!!! Quickly removed power and checked the impedance to ground after the fuse and measured 12ohms. Yikes. So that is why the original fuse blew.
So now I need to try and figure out what component hanging off of PPBUS_G3H is shorted to ground. I would have expected it to be a toasty bit of carbon by now but I guess if it is a FET it can withstand a fair bit of current. One thought that I had was to apply the power and then run around the board with my infrared thermometer and find the hot spot. Any other ideas?
Good sleuthing Papabear
My latest acquisition is a MBP 15" unibody 2.8GHz ....<snipped>
So now I need to try and figure out what component hanging off of PPBUS_G3H is shorted to ground. I would have expected it to be a toasty bit of carbon by now but I guess if it is a FET it can withstand a fair bit of current. One thought that I had was to apply the power and then run around the board with my infrared thermometer and find the hot spot. Any other ideas?
Dadioh, you're on the right track. I'd check all the power FETs that generate all the other lower voltages i.e., 5v, 3.3v etc. With no power connected, since FETs are like switches that are controlled by GATE signal, I'd think that all FETs SOURCE to DRAIN connection should be "open/high impedance" on the PPBUS_G3H bus when there are no GATE signal present (positive voltage signal).
BTW: 1v at the CPU is actually the correct Vcc voltage, except that it should not be present until a "power on" signal is active.
Last edited:
Good plan. I will see what I can find out.
Yes. I knew 1.0V was the correct voltage. I was wondering why it came on without the SMC telling it to but with all of the higher voltages messed up who knows what the logic is doing.
Hi Guys, great info so far. I have a very similar problem to some of you that perhaps you can help me diagnos.
Machine: MacBook Pro Unibody 2009 2.26GHz 13"
Symptoms: Dead. Connecting magsafe does not light indicator on magsafe plug.
Cause: Water damage
Tried so far: First I cleaned with 99.9% Isopropyl Alcohol and allowed to dry thoroughly. At the moment I have the logic board removed with nothing connected to it but the DC-IN board. I originally suspected the DC-IN board but having just tried a replacement I don't think it's that.
Here is a pic from earlier in the thread of the underside of the DC-IN board:
When I measure the voltage between + and ground on the underside of the DC-IN board with the board NOT plugged into the logicboard I see 6.95V
When the DC-IN board is connected to the logic board and I measure again I see: 0.52V
I am guessing that the sense line is telling the PSU that there is a problem, so rather than ramping up the voltage as it would normally do, it is decreasing it to a trickle.
Any suggestions on further diagnostics?
Thanks
Machine: MacBook Pro Unibody 2009 2.26GHz 13"
Symptoms: Dead. Connecting magsafe does not light indicator on magsafe plug.
Cause: Water damage
Tried so far: First I cleaned with 99.9% Isopropyl Alcohol and allowed to dry thoroughly. At the moment I have the logic board removed with nothing connected to it but the DC-IN board. I originally suspected the DC-IN board but having just tried a replacement I don't think it's that.
Here is a pic from earlier in the thread of the underside of the DC-IN board:
When I measure the voltage between + and ground on the underside of the DC-IN board with the board NOT plugged into the logicboard I see 6.95V
When the DC-IN board is connected to the logic board and I measure again I see: 0.52V
I am guessing that the sense line is telling the PSU that there is a problem, so rather than ramping up the voltage as it would normally do, it is decreasing it to a trickle.
Any suggestions on further diagnostics?
Thanks
Last edited:
Did you remove the logic board and clean the back side as well? Inspect it careful for corrosion or for burnt components. Is there an odor of burnt components?
Check the voltage on the sense line when pugged in to the macbook and charger.
Also, on the back side of the board near the where the magsafe plugs in (under the speaker) there is a white fuse. With power off, measure the resistance across it.
There are many different reasons that can account for the SMC not sending the signal to the magsafe to provide full current. We can try and walk you through the more common ones. Report back on the first steps above.
Hi, thanks for the reply.
Yes, cleaned both sides thoroughly but carefully. I can't see any obvious corrosion or burnt components, and no odour.
It shows 0V. This is with the logicboard removed from the case with only memory and DC-IN board connected (no battery)
Shows about half an ohm of resistance, so I assume it's good. (0.5 when on the 200OHM setting)
Thanks
Yes, cleaned both sides thoroughly but carefully. I can't see any obvious corrosion or burnt components, and no odour.
It shows 0V. This is with the logicboard removed from the case with only memory and DC-IN board connected (no battery)
Shows about half an ohm of resistance, so I assume it's good. (0.5 when on the 200OHM setting)
Thanks
OK. The zero Volts on the sense line indicates an issue. The main fuse is OK so next step should be to check if G3Hot is present. This can be seen at the system startup jumper pads near the keyboard connector. One side measures zero Volts and the other should read 3.4V.
Attachments
Last edited:
I'm seeing 0V on both the pads. I'm measuring between the 0V on the DC-IN board and each pad in turn.
That means you have no G3hot voltage. The entire board will be dead and unresponsive until you figure that out. There were some good discussions on that earlier in the thread.
Just a thought chiming in: Since Beakster saw only 0.52v with the magsafe connected to the logic board, I'd guess that G3HOT will not be present.
I mentioned previously that the magsafe adapter only output the 16.5v when there is sufficient load on the magsafe "plus" supply line (this voltage presence is temporary). The momentary presence of this voltage then allow G3HOT to occur, and that in turn allow the SMC to power up and then sends a "keep alive" signal to the magsafe. If keep alive signal fail to occur, the magsafe drops the 16.5 output, and thus you see the 0.52v. Just my 2 cents.
"Chiming in"
My favourite sound... Love that moment in the Pixar Movie "Walle" when he finishes his charge cycle. Classic.
Anyways... The Commander is right. If the SMC is unhappy then you can have power removed from the magsafe. But not always. Welcome to the wonderful world of SMC.
I have one board that flashes the green LED on and off. When I check the CHRG_OK signal coming off the charger device (pin 14 I think) I can see it pulsing between 3.3V and a lower voltage indicating that it alternating between being happy and sad. I suspect some feedback in the charging circuit is detecting over current. Still working that one out.
Hi, everyone.
First of all, I'm sorry for bad english.
I have a Macbook Pro A1278 liquid damage in my hand. Oxidized zones cleared. Although it is plugged into the charger light is on, nor what the machine would start charging. I ran the machine in the above-mentioned method.
But high-speed fan works, such as @ Dadioh said, the sensors not work, and dvd-rw does not seem to have the battery. Other works for all devices.
I tried the battery charging light is not lit. So the machine does not see the battery and dvd-rw. Naturally, the battery will not turn on the machine. Just trying to charge the instrument.
I did some measurements on the machine. Everything seems the pictures below.
Now how can I solve this problem. What is problematic parts. Do you have people who can help me?
The no battery icon indicates the CPU/SMC/CHARGER ICs did not know that the battery is plugged in (or the battery is dead, and thus not able to communicate via the I2C bus (SCL and SCD lines).
- you have a fairly good condition system since you see power all over the board including the voltage at the battery connector (most FETs are intact)
- With the magsafe disconnected and battery plugged in, do you see the 12v on the battery connector and fuse near that battery? If not, perhaps the battery is dead/totally discharged.
- the white block near the display connector is NOT a fuse. Dadioh said that it is a capacitor and has nothing to do with power system.
- measure the DC resistance (no power) between SCL and SCD lines. It should be around 2kOhm the pull-up resistors on these lines to 3.42v is 1kOhm each.
Yes. Measurements of this piece I realized that my insurance. I think diode or resistor. Another issue is the battery are secure. In other words, the device works well in another.
This device is currently only running @ Dadioh the first message, said method. While holding down the Power button adapter I wear, I press the button again, trying to leave after a few seconds. But the adapter I can now make a reservation the same process again. The battery is completely empty. But the other device is charging.
So Can you show the location of these roads you mentioned? Where exactly?
The 9-pin unibody internal battery connector has pins containing these signals.
Pins 1/2/3 is batt+, pins 789 is batt-, and pins 4/5 are SCL/SDA (oops previously I said SCD, it should say SDA) lines.
We have that message, then the insurance segment. I changed the fuse is defective as a solid. Now, unfortunately, the computer will not open in any way .
https://forums.macrumors.com/posts/12743007/
Ne önerirsin?