Repair Actions/0002: Difference between revisions

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* Check VREG_CPU_PWRGD (VREG_CPUCORE_VCS_PWRGD on Xbox 360 S/E motherboards)
* Check VREG_CPU_PWRGD (VREG_CPUCORE_VCS_PWRGD on Xbox 360 S/E motherboards)
** If present, replace Southbridge
** If present, replace Southbridge
** If missing, check continue below
** If missing, check pullup
*** On Original Xbox 360 motherboards, check V_5P0
*** If pullup is fine, continue below


== VREG Circuit ==
== VREG Circuit ==

Revision as of 12:50, 20 January 2023

Note  This page is a technician's reference and is not intended to teach diagnosis and repair of electronic circuits.
ERROR_V_CPUCORE

VREG_CPU_PWRGD is driven high by the V_CPUCORE controller as long as the rail is within tolerance. If V_CPUCORE ever drops out of tolerance, the signal is de-asserted, causing the SMC to enter EC_FATAL and the 0002 code to be displayed on the front panel.

Short Circuit

  • Check if V_CPUCORE is shorted
  • If it is, check each phase to localize short
    • 3 phases on Xenon, Zephyr, and Elpis
    • 2 phases on every other board
  • Check V_CPUCORE decoupling capacitors near and under CPU
  • If all components are fine but the short remains, replace the CPU

VREG Enable and Power Good

  • Everything in this section must be checked quickly, as the SMC will shut down power upon entering EC_FATAL
  • Check VREG_CPU_EN signal components
    • If components are fine but the signal is missing, replace Southbridge
  • Check VREG_CPU_PWRGD (VREG_CPUCORE_VCS_PWRGD on Xbox 360 S/E motherboards)
    • If present, replace Southbridge
    • If missing, check pullup
      • On Original Xbox 360 motherboards, check V_5P0
      • If pullup is fine, continue below

VREG Circuit

  • Everything in this section must be checked quickly, as the SMC will shut down power upon entering EC_FATAL
  • Check if V_CPUCORE is in within tolerance
  • If it is, replace the PWM driver and recheck PWRGD
  • If it isn't, check each phase of V_CPUCORE VREG and PWM driver
    • 3 phases on Xenon, Zephyr, and Elpis
    • 2 phases on every other board