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[SOLVED]820-00239 touchbar madness

iambehr

iambehr

Member
Hello,
I got a new one in the shop today. Left side liquid damage. Replaced tons of ruined passives around U3200. Board would not get power from USB C charger before, now it gets power, charges, and boots.
I had to reconnect pins 19 and 21 on the J4402 "DFR Touch Connector" due to corrosion eating the pads. So far all else looks OK.
However, left side fan is not spinning at all and the right side fan is spinning on high. Internal diagnostics only report generic fan error. Diagnostic will spin the left side fan for a few seconds and stop.
Anybody have an idea of what to check?
Looks like there are separate left and right fan control and tach reporting channels, as well as separate left and right fin stack temp sensors.
The fan/keyboard connector has escaped any damage.
My best guess is left side temp sensor, and I will check that tomorrow.

Thanks,

Stefan
 
D

dukefawks

Administrator
Temp sensors should be fine if diagnostics doesn't report error. I'm not even sure if on the 00239 the fans should spin when cold. Maybe the fast fan is the issue because of a tacho signal issue.
 
iambehr

iambehr

Member
Board is on my low priority queue at the moment.
Switched fans and same behavior. Ridiculous but there is fan control circuitry on the back of the keyboard. The keyboard ssembly is a PCB substrate. I see no signs of corrosion on it however.
Standard behavior is no fan spin I believe. With tpad unplugged both fans spin, right fan still at high speed.
 
iambehr

iambehr

Member
FIXED!

All repairs listed:

Replaced passives around U3200. Lots of ruined caps and resistors.
Ran wire to reconnect pins 19, 21, on the DFR Touch Connector.
Fan control at Q6050 was screwed up. Had to replace R6051 and run wire to reconnect it to pp3v3_s0.

My first time with a touchbar mac... and I hope, my last... haha.

Thanks,

Stefan
 
G

Greg

New member
iambehr said:
Board is on my low priority queue at the moment.
Switched fans and same behavior. Ridiculous but there is fan control circuitry on the back of the keyboard. The keyboard assembly is a PCB substrate. I see no signs of corrosion on it however.
Standard behavior is no fan spin I believe. With tpad unplugged both fans spin, right fan still at high speed.
Click to expand...

Hi sorry to revive this old thread but is this true about the keyboard? As i just revived one of these machines by removing a couple of shorted capacitors but the fans runs constant high and system very slow,
Was told liquid into touchbar and keyboard both dont work, But track pad does work, is there a thermal sensor in touch bar or keyboard?
 
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