820-00281-A A1707 with No Chime Or Display But Fans Spin

peeka79

Member
Hi Guys/Gals, I have a 820-00281 A1707 that is getting 19.91V On ampMeter and 1.2 amps at start up...it has No Video either on Display Or External Display...You can hear the iPhone Charging bling whenever you plug in the Charger but No Video...Also the caps Lock light comes on when fans are spinning...pp3v3_g3H is present (3.3v) PPbus_G3H is also present (12.7V) 2 caps had corrosion C7601, and C7664..Both Were Removed and replaced from a identical Donor board...Any suggestions on Where to start....Thank You in Advance...
 

peeka79

Member
Hi 2informaticos, And Thank You SO Much for the response...Yes the caps Lock Led does respond to being Pressed (Light goes on and off When Pressed)...There is No USB Activity as I tried with a USB Mouse and also Tried a USB Keyboard for a PRAM reset but no go...ANY help is GREATLY Appreciated :)
 

2informaticos

Administrator
Staff member
Board is runing, if you get Caps Lock reaction.
No USB activity and no internal/external video at same time, is very strange in this case.
All USB ports the same?
Check them all for activity.
 

peeka79

Member
All USB ports Give the same Values with the USB-C AmpMeter Plugged into them...Fans Spin with each USB port Plugged in...and Caps Lock Responds with each one also
 

peeka79

Member
Are there any Particular Lines I can Check?...Sorry...These Boards are CRAZY with all these USB Controller Chips!!!...LOL
 

Bouba148

New member
Did you checked all your S0 rails ? If you have PPVCC_S0_CPU normaly it should be OK.
Is your CPU over heating ?
Plus you can hear the charging boing this is weird....
 

peeka79

Member
Have Not checked S0 Rails Yet...CPU is Pretty Hot when fans are spinning...And Yes I can hear the Boing when the USB-C Is plugged into the Machine. Even when the fans are spinning while on Battery and the charger gets plugged in Machine makes the Boing Sound...Which S0 Rails should I check?
 

peeka79

Member
Yes I do have another Screen. Also...Here are Some S0 Rails I just Measured...(With Fans Spinning and Charger Attached...

PP5V_S0 = 5.1V
PP3V3_S0 = 3.3V
PP3V3_S0_GPU = 0.00V
PP1V8_S0 = 1.79V
PPCC_S0_CPU = 1.2V
 

2informaticos

Administrator
Staff member
If someone has similar board, with dedicated GPU, maybe can post if GPU VCORE appears directly on the boot.
 

peeka79

Member
Okay...I do have another 820-00281 Board that also doesn?t turn on...No Liquid damage but gets 19.89V on USB-C Amp-meter but goes from 11amps to 61amps then back to 61Amps and just keeps doing that No warmth on the board anywhere...Any Suggestions on getting that Board To power on?...Any Help is GREATLY APPRECIATED ?
 
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