Need help with 820-00165

[mon2]

Re: Need help with 820-00165

See attached.

The ON/OFF of the logic board has numerous feeds including the SMD pads you are shorting with the tweezers.

Then there is the keyboard ON/OFF. I recall a few cases like yours on this forum where the keyboard (maybe due to liquid damage??) was flaky for the ON/OFF function.

To confirm, test with the keyboard again. If the results are not 100% everytime to turn the macbook ON/OFF, then you will need to monitor the voltage on

pin # 20 of connector J4800.

You should see a logic high (~3v4) when the key is not pressed

and then logic LOW (~0 volts) when the key is pressed. If this status is not low enough, the logic board will not turn on.

Confirm this detail with the multimeter.

Post the measurements to move forward.

[goksi75]

Re: Need help with 820-00165

I put the logic board in a new case and now I have the following situation, the board goes on and off on the button and it takes a little longer to hear chime 30 sec,now board go to sleep mode but wake up and throw the picture on the lcd but it takes 1-2 minutes and after that he won't play the video on youtube, after the restart he normally plays the video from youtube, this motherboard really bothers me.

[mon2]

Re: Need help with 820-00165

Perform the PRAM RESET on the board.

https://support.apple.com/en-gb/HT204063

Hold down the above keys till you hear the chime for the 2nd time.

[goksi75]

Re: Need help with 820-00165

I did it but again it's all the same, and I noticed that the board was working a little slower.

[mon2]

Re: Need help with 820-00165

Remove all power.

Disconnect the trackpad and test again with the ON/OFF using tweezers. Is it faster?

With the logic board mounted, you must use R5116 for the ON/OFF function.

See attached.

Test this multiple times (without trackpad attached).

[mon2]

Re: Need help with 820-00165

I think you will find that the logic board will boot normally without the trackpad connected ?

Sounds like a liquid spill on the trackpad / keyboard fault.

Use an external USB keyboard & mouse and load up the following program:

https://www.tunabellysoftware.com/tgpro/

Enable to monitor all sensors.

Suspecting that you will see normal readings WITHOUT the trackpad connected.

Then some high readings for the sensors WITH the trackpad connected.

Confirm it but interested to know if the logic board works normally when the trackpad is not connected.

Jumping ahead, the trackpad should be replaced as there are some embedded sensors that are failing. The trackpads are common on Aliexpress or you can take from a donor board. Not a bad idea to source the keyboard as well which are <$20 on Aliexpress and we can buy locally for about the same price from Mobile Sentrix.

Believe that you have already tested another trackpad cable ? Be 100% sure that the cable for the trackpad matches your pin-to-pin pitch. Personally have seen where the cable would fit but it was the wrong pitch and caused heating up of the logic board and other faults. The trackpad cable just was not the right part number for this trackpad and logic board.

A fresh cable is a good idea to test and buy with the trackpad. Any shop with trackpads can supply the cable.

There are no public documents (schematics) on the trackpad for the macbooks (that I am aware of).

PS: Plan B is to consider a non-working A1466 from Ebay or similar for donor parts and more fun. We have done this with a very high degree of success. Most were < $ 100 for the macbook but often, sellers will remove the SSD. Most needed < $ 5 of parts to fix.

https://www.aliexpress.com/wholesale...psort=1&page=1

[goksi75]

Re: Need help with 820-00165

Everything is the same when I disconnect the trackpad and test again with the ON/OFF using tweezers.Longer to hear chime, and apple logo is on the screen for about 30-40 seconds and then just enters the system.

[mon2]

Re: Need help with 820-00165

Remove all power -> remove the SSD.

Do you have a battery connected on this logic board ? If yes, can you disconnect it - just for testing.

Then power up again. Is it faster to turn on ? The missing SSD will cause a slow boot.

Update:

Does the battery work with this logic board ? Charging ok ?

Measure & post the voltages of:

SMBUS_SMC_5_G3_SCL
SMBUS_SMC_5_G3_SDA

the above are different SMBUS (I2C) connections and linked to the SMC & battery + charger IC.

[goksi75]

Re: Need help with 820-00165

All the while I was doing this, battery is disconnect. SSD is present.

[mon2]

Re: Need help with 820-00165

Everything is the same when I disconnect the trackpad and test again with the ON/OFF using tweezers.

So it is normal IF the trackpad is disconnected. Right ? Or is still slow ?

[reformatt]

Re: Need help with 820-00165

Seems to be going round in circles. Couple of pointers.

Fan will run fast and throttle CPU without trackpad connected. A 3437 or 00165 board will automatically start with no battery connected and power is applied. Holding the on/off button down (or shorting out the contacts) for 10 secs or more, will put system into SMC bypass mode, resulting in a very slow system as well.

Original fault disappeared when moving the board, so I'd say it's still LIO board/cable or screen magnet related.

[smzlwan223]

Re: Need help with 820-00165

It's a problem I've had a lot of trouble with in the past, and I've been working on it, and I hope it helps. This is a rough sketch I made for you. I hope you can understand it. My English is not very good, can only use the translation software to communicate with you.

[mon2]

Re: Need help with 820-00165

@smzlwan223 - many thanks for your great feedback.

So you are replacing the reset supervisor IC (Texas Instruments) with a RC circuit ?

Was U8130 (TPS3808G33) defective on your logic board ?

Will review with the OP.

@goksi75 - measure and post the voltage of PM_RSMRST_L.

Interested in the voltage when the logic board is NOT waking up.

The resistor @ R8133 is required. Confirm it.

[goksi75]

Re: Need help with 820-00165

PM_RSMRST_L 3.3V

PM_RSMRST_L 0.0V when the logic board is not waking up

when I touch R8133 pin 2 the motherboard restarts

[mon2]

Re: Need help with 820-00165

Sounds like R8133 is is defective or has a solder connection fault.

Apply fresh solder onto pin #2 or you can try to replace it - it is a tiny bugger @ 0201 size so recommend to reflow it with low air pressure + high heat OR use point to point soldering.

Just touch pad # 2 with fresh solder. Do not take too long else pad #1 will melt and the resistor will come off.

The value of this resistor is NOT critical and any value like 10k-100k will work here if you need to replace it.

Continue to post your updates.

[goksi75]

Re: Need help with 820-00165

Replaced R8133 but the same.

Let me try what he suggested @smzlwan223.

[mon2]

Re: Need help with 820-00165

It is ironic - for our product designs, we use similar reset supervisor devices so that we can guarantee that the reset line is released after a known period of time. The supervisor ICs are more robust than RC circuits but of course, try the idea.

@smzlwan223 has proven it worked for him.

I believe what may be the fault here is that the IC has a threshold value to monitor = PP3V3_SUS. When that rail is within the specified voltage range, the RESET output is high impedance and the pull-up resistor does the job to make this pin HIGH = all is good.

That is, the PP3V3_SUS may be perhaps too low so RESET remains LOW. In general, the reset supervisor threshold should have been a lower detect value like 2v8-3v0.

[goksi75]

Re: Need help with 820-00165

Most likely I'm going to give up on this logic board.

[mon2]

Re: Need help with 820-00165

NO - NOT YET You are very close. Just follow the suggestion from above.

We now know the root cause which is the RESET# line remains low due to this voltage supervisor.

I am curious - when the unit does not power on - what is the voltage of PP3V3_SUS ?

That is, this rail is being sensed by U8130. If it is not in range, the output will remain @ LOW and the unit will not power on.

Post the voltage of PP3V3_SUS when the unit is not waking up.

[goksi75]

Re: Need help with 820-00165

PP3V3_SUS 3.33V and as I measure board power off and power no currently.