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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...
It has previous repair to 3V3_S4 so it is highly likely thats the case.
When I pulled R6999 the short was on the 'right' side (so a LOT of potential components)
Voltage injection best method to see what gets abnormally hot?
Diode mode to ground at L7560 = 0.344v
3v3_SUS is 0v
U7501 looks clean (but also fresh solder on test points in the area so likely board has been repaired previously)
Hi 2info,
Tried PRAM reset and no difference - audio hardware on the board is not detected. Having left the board overnight it is now stuck at 5V again and won't jump to 20v on either port.
Diode mode on 3v3_G3H is 0.101v so doesn't appear shorted now. Something bizarre going on because I had...
Hi guys,
Got a 3437-B which had fluid damage around U1950. Cleaned area and replaced U1950. Getting green light but no fan spin. Rails so far as follows:
PPBUS_G3H = 8.56V
PP3V3_S5 = 3.0V
PP5V_S5 = 5.0V
PP3V3_S4 = 0V
Struggling to understand on schematic where S4 rails will...
While waiting for del of a bench PSU to check this - tried it again and the damn thing has powered on and booted. I still have a short somewhere as it intermittently reboots. Only clue I have is that there are now no audio devices listed in output! (And no chime now whereas before audio worked...
Sorry, for some reason I though I had an 85W charger connected not a 60w, so 16.44 is obviously perfectly fine
Getting OL diode mode to ground on both 19 and 20
This board is now becoming a nightmare.
While testing for DP_INT_HPD board stopped powering on and is now stuck at 5v, with a short on PP3V3_G3H. Removed R6999 and it the short is on the "right side" and so could be anywhere. Any advice for trying to locate the short?
Hi guys,
Got this 820-00165 which initially had minor corrosion around U7090, no green light. Found blown D7012, replaced and now got green light but no fan spin.
PPDC_IN is only 16.44v, PPBUS_G3H is 0.3v
Any idea where to go on this one?
Apologies for the delayed response, been away and just coming back to this one!
I get a momentary 3.3 and 5v pulse on those rails several seconds after power on (with screen disconnected) but then nothing.
Will DP_INT_HPD only go high when screen is connected (and detected)?
Update to this one.
Symptom is the same with known good Display assembly and flex cable.
System chimes, boots, get kb backlight and caps lock. Has booted into OS if connected to external display. Internal display is not detected in display prefs, no image on screen.
Where should I go from...
Hi guys,
Newbie here still learning!
I have an 820-00840 here with no image.
Board has no signs of present fluid damage but appears to have had a previous repair to PP3V3_S4 (wire to replace broken trace).
Board boots to OS fine and video fine when connected to external screen.
Display...