Xbox 360 0021

Xbox 360 SMC Error: 0021

ERROR_NO_PCIE
PCIE link did not enter L0 after seqUnReset time passed

This means the GPU to Southbridge PCIe bus was not able to be set up properly

GPU Revision


 * There are many GPU models used on the 360s an incompatible GPU will cause the PCIe link to fail
 * Check that the GPU matches the correct model for the board:
 * Xenon, Zephyr_A: Y1 X02056 or X817791 (90nm GPU and eDRAM), Elpis X819195 (80nm GPU and eDRAM)
 * Zephyr_B: Y2 X02127 (80nm GPU and 90nm eDRAM)
 * Zephyr_C, Falcon: RHEA X810480 or X816970 (80nm GPU and eDRAM)
 * Jasper V1: Zeus X817793 (65nm GPU and 80nm eDRAM)
 * Jasper Kronos: Kronos1 X820894 (65nm GPU and eDRAM)
 * Note: Kronos1 GPU does work on Jasper V1 if moved over

PCIe Bus Filter Caps


 * Check all caps are 0.1uF (6.3V, X5R), and continuity from them to the other side of the PCIe trace
 * Most boards have test points on the other side of each trace to verify this
 * Xenon:
 * GPU Side: C4D1, C4D2, C4D3, and C5D1
 * Southbridge Side: C2C1, C2C2, C2C3, and C2C4
 * Zephyr, Falcon, Jasper:
 * GPU Side: C4D1, C4D2, C4D3, and C4D7
 * Southbridge Side: C2C1, C2C2, C2C3, and C2C4
 * Trinity:
 * GPU Side: C5E1, C5E2, C5E3, and C5E4
 * Southbridge Side: C3D2, C3E1, C3E2, and C3E3
 * Corona/Winchester:
 * GPU Side: C5E1, C5E2, C5E3, and C5E4
 * Southbridge Side: C3D3, C3D4, C3D5, and C3D6

PCIe Clock
 * Check junction between the sets of 33 and 49.9 Ohm resistors for proper 100 MHz differential clock
 * If bad/missing signal, check the values of the resistors as follows:
 * Xenon:
 * Check R3C6 and R3C10: 33 Ohms
 * Check R3C5 and R3C9: 49.9 Ohms
 * Zephyr, Falcon, Jasper:
 * Check R4B27 and R4C8: 33 Ohms
 * Check R3B5 and R3C9: 49.9 Ohms
 * Trinity:
 * Check R3B21 and R3C2: 33 Ohms
 * Check R3B20 and R3C1: 49.9 Ohms
 * Corona/Winchester:
 * PCIe Clock is internal to the Southbridge, but there are test points
 * Check R3D28 and R2D29: 10K Ohms
 * Test Points: DB3R6 and DB3R7
 * If still bad/missing clock signal, replace clockgen chip:
 * Xenon: Cypress CY28517 U3B4
 * Zephyr, Falcon, Jasper: HANA U4C2
 * Trinity: HANA U3B1
 * Corona/Winchester: Southbridge U3D1

Southbridge or GPU


 * If everything so far is fine, Southbridge or GPU is likely at fault
 * There is no reliable way to tell which chip is at fault
 * It is recommended to replace Southbridge first:
 * Phat: U2C1
 * Slim: U3D1
 * If all else fails, replace GPU:
 * Phat: U4D1
 * Slim: U5E1