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820-3330 intermitting startup and orange light - fan twitch if dead

2informaticos

2informaticos

Administrator
Staff member
Check if you get 3V42 when R7011 is removed.
If yes (not normal for original charger), run a wire from 3V42 to CHGR_ACIN.
It should work with fake charger.

For original charger, R7010/11 must remain both connected.
In such case, cut off trace to pin 3 and put there 3V42.

All this supposing 3V42 is always stable...
 
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Fizzl92

Member
While fans twitch 3V42 is 3.393V stable.
If R7011 is removed 3V42 is gone too aswell as the green light.
So i put iR7011 back on, cut the trace and run a wire from 3v42 to pin 3. Now rails are stable. But the board is not working. Most of the times fans just twitch once now and thats it. Sometimes it turns on but after a few seconds right back off.
I checked the rails and
5V_S5, 3V3_S5, 5V_SUS, 3V3_SUS are present.
5V_S3 is 0V,
3V3_S4 and 3V3_S3 are 0,7 V and falling. I followed this path and the enable is missing cause U7970 has 0V at Pin 1&2. No Short at these two pins and also no short at 5V_S3 is, 3V3_S4 and 3V3_S3.
 
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Fizzl92

Member
It starts from battery alone everytime. Battery + charger also. But charger alone is not working very well. (your GHGR_ACIN mod is still on the board)
 
2informaticos

2informaticos

Administrator
Staff member
Does it charge the battery?

"But charger alone is not working very well"
Sometime works on charger alone?

Keep the ACIN mode for the moment.
Post CHGR_A/BMON when doesn't want to work.
ACOK steady now?
Also run ASD EFI and look for any error; charger and battery connected.
 
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Fizzl92

Member
Yes, it charges the battery with orange light and last battery indicator light blinking too. On charger it only works sometimes randomly/intermitting. But mostly its dead. As it was from the beginning.
With charger only plugged in, green light and dead:
ACOK: 2,24 V steady
AMON: 0.03 V
BMON: 0.04 V
If i then plug in the battery and charger it starts, light turns orange AMON goes up to 0,4 V and BMON stays low ~0,05V but it works and shows question mark folder.
ASD results follow as soon as possible.
 
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Fizzl92

Member
Unfortunately i can run ASD on monday next time as i am not at work until than. Just took the board with me and dont have a 2012 screen here - just one for 2011 model... So i post ASD results on monday. Is there anything else i can do until than with the mesurements from above?
 
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Fizzl92

Member
At the ISL itshelf:
Pin 17-18: 6.2 Ohm
Pin 27-28: 24.3 Ohm
This includes ~3.5Ohm from my multimeter probes.
I changed the ISL already so there is flux around it but there was no sign of corrosion anywhere on the board and inside the device as i started with this.
 
2informaticos

2informaticos

Administrator
Staff member
Should be good to test with PSU and 85W cable.
Or at least fake charger.
This way you can discard leakage issue on charging circuit.
Original charger detects leakage and can get blocked...
 
2informaticos

2informaticos

Administrator
Staff member
The thread is split in so many posts, dificil to find signal values...
Please post again basic signals and exact voltages, on original 85W charger (no battery).
Don't forget SMC_ADAPTER_EN and SMC/PM_BATLOW_L.
 
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Fizzl92

Member
Yeah this thread is way to big alredy and this board is really killing me... Thank you for your patience!
Since your CHGR_ACIN mod is on the board signals are steady now. Now it turns on ~50% of the time but turns off after a few secomds moslty. Its rare that it stays on. If it wont start at all fans twitch one time ant thats it. Green light is there. I get with board outside the case, original 85W charger and no battery at the moment its dead:

PPBUS_G3H: 12.54 V
P18V5_DCIN_CONN: 16,96 V
PP3V42_G3H: 3.40 V
PPVRTC_G3H: 3,33 V
5V_S5: 5.03 V
3V3_S5: 3.30 V
5V_SUS: 5.03 V
3V3_SUS: 3.33 V
3V3_S4: Jumps up if i plug in the cable and falls slowly down to 0 V after that one spike. So theres something wrong here i suspect
5V_S3: 0.00 V
3V3_S3: Same as 3v3_s4 as commected to is via L3505

I followed 3v3_S4 and the enable is missing cause U7970 has 0 V at Pin 1&2. No Short at these two pins and also no short at 5V_S3 is, 3V3_S4 and 3V3_S3.

SMC_BATLOW_L: 3.06 V (is that ok? - R5040 is 98 kOhm)
PM_BATLOW_L: 3,29 V
SMC_ADAPTER_EN: 3,36 V

Any importent signal missed so far?
 
2informaticos

2informaticos

Administrator
Staff member
Don't you get a pulse at L7220?
If cannot see anything when connect charger, then trigger SMC_ONOFF_L and check reaction at L7220 and PM_PWRBTN_L.
Do you always get steady high level for PM_RSMRST_L and PM_PWRBTN_L when charger connected?
I'm especially inetrested for signal levels when board doesn't start...
 
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Fizzl92

Member
I do get a pulse at L7220 if i connect the charger and board doesnt wanna work (fan twitch). If the board starts up it jumps to 4.3 V and back down to 0 V is the board turns back off. If it starts up and works fine it jumps to 5.03 V.
PM_PWRBTN_L jumps to 3,38 V and stays there even if the board turns back off. Same behaviour for PM_RSMRST_L but it reaches only 3.02 V.
Signal levels are the same it the board doesn?t start at all(fan twitch) and if it starts but turns off again after a few seconds.

I also noticed that sometimes the light in the charger turns on if i connect it, than off for a second and back on. Maybe thats cause i connect the charger 10x in one minunte of maybe its important...
 
2informaticos

2informaticos

Administrator
Staff member
If you trigger SMC_ONOFF_L always fan twitch?
If board always try to start and goes off instantly (or in seconds), looks like some SMC sensor issue.
But in such case, it should always start in SMC bypass.
Did you start correctly in that mode?
Connect battery and charger, run corresponding ASD and report if any error pops up.
Se On Error Mode to Continue and unmark HDD and Memory tests...
 
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Fizzl92

Member
If it works power button works fine - even on keyboard. If its dead shorting R5016 pads does not result in fan twitch - no reaction at all.
I did SMC bypass like that: With charger connectec i hold power button, unpluged charger, plugged it back in while still holding power for 10 more seconds. I did not need to wait for 10 seconds. The board starts earlier and as i described it shows slightly other symptoms (like quater fan spin instead of just fan twitch) if i did that. So i guess it worked.
If i am right i should release power for 2 seconds and hold it for additional 2 seconds after the 10 seconds after plugging the charger back in. But as it already starts up i did not see the need for that.
Not sure if thats a problem/ my fault...
Thank you. I'll run ASD on monday and report back.
 
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