Hi all.
I have a dead 820-00269 from an A1706.
Missing PPBUS_G3H.
I get 20v on F3001, however no voltage on F8400.
I removed F8400, and injected 1 volts into pin 1 and found U7960 getting very hot.
I removed that and there still appears to a direct short (zero ohms) to ground on the pads of pins 6,7,8 - (PPVCCIO_PHASE, which becomes PPVCCIO_S0_CPU, after L7960)
With U7960 still removed, I now get 13.03v on pin 1 of F8400 (PPBUS_G3H).
I understand that some CPU rails will normally appear to have very low resistance, but I don't assume it should show zero resistance?
The only other components on PVCCIO_CPU are a bunch of caps - C7964, C7965, C7966, C7967 and C7970 and C7971
I removed C7964 but the short remains.
I've removed the board and applied 1v to PPVCCIO_S0_CPU.
It still shows a short -its drawing approx 2.5A at 1v.
Nothing seems to be heating up however.
A dead CPU perhaps?
Any suggestions greatly appreciated.
I have a dead 820-00269 from an A1706.
Missing PPBUS_G3H.
I get 20v on F3001, however no voltage on F8400.
I removed F8400, and injected 1 volts into pin 1 and found U7960 getting very hot.
I removed that and there still appears to a direct short (zero ohms) to ground on the pads of pins 6,7,8 - (PPVCCIO_PHASE, which becomes PPVCCIO_S0_CPU, after L7960)
With U7960 still removed, I now get 13.03v on pin 1 of F8400 (PPBUS_G3H).
I understand that some CPU rails will normally appear to have very low resistance, but I don't assume it should show zero resistance?
The only other components on PVCCIO_CPU are a bunch of caps - C7964, C7965, C7966, C7967 and C7970 and C7971
I removed C7964 but the short remains.
I've removed the board and applied 1v to PPVCCIO_S0_CPU.
It still shows a short -its drawing approx 2.5A at 1v.
Nothing seems to be heating up however.
A dead CPU perhaps?
Any suggestions greatly appreciated.
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