820-00840 no POST

chrislewis85

New member
Hi guys,

Got an 820-00840 that I got for new screen (usual flexgate problem)

Noticed that machine has a 'cold boot' issue where it randomly powers off or restarts during use, especially when cold booting. First few times it struggles to even get to login screen.

After a warm up period is seems far less frequent.

Having opened her up, noticed a very small amout of corrosion around U7370 and L8030 / Q8030.

Have flux and boiled these 2 spots, but now board is stuck at 20v 0.03A. Trackpad clicks when plugged in but CPU does not get warm.

I have checked and have no VCORE voltage present at L7210/20.

From reading other threads I have noticed that L8060 and L7900 seem to have lower than expected resistance in diode mode (0.036v and 0.086v)

Any suggestions?
 

2informaticos

Administrator
Staff member
Something went wrong when you rework mentioned areas.

You cannot search VCORE with only 30mA on USB port; many more voltages missing.
Do you get 3V3_S5 at least (L7690)?
 

chrislewis85

New member
L7670 = 5.09V
L7690 = 3.3V
L8410 = .01V

L7030 = 7.08-7.11V (seems to roll up and down)
L7730 = 1.04V
L7430 = 0V
L7410 = 0V
L7420 = 0V

L7210 = 0V
L7220 = 0V
L7370 = 0V
L8060 = 0.99V
L7900 = 1.00V

L8030 = 1.2V
L7960 = 0V
 

2informaticos

Administrator
Staff member
L7960 voltage must appear before CPU core.
Post diode mode to ground at this coil; switch to ohm mode, if very low value.
 
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