创维8R96主板不开机维修一例（创维a8r900主板维修）

接修一块创维的8R96的板，板号：5800-A8R960-0P00，主芯片型号：RTD2992。

据描述故障现象为开机花屏，然后黑屏。之后不开机，隔几天后可能会再开机。

通电试机的确花屏，竖带雪花条，由于故障出现的时间较快没拍到图，之后再试一直开不了机，测各路供电正常，ddr供电1.52v跟基准电压0.76v正常，测各路供电回路压降没发现问题，接上打印如图：

打印只显示这么点，是什么意思呢？在RTD方案这个底层打印的意思是主芯片向emmc存储读取不到BootLoader引导程序，拆开散热片看见主芯片上的胶都变色了说明工作的时候温度很高的。

怀疑虚焊于是刷上焊油用风枪吹进去然后放在bga返修台上加热焊接完成，冷却后试机打印如下:

U-Boot 2012.07-svn572608 (Sep 10 2013 - 17:43:35)

GPU : BISR testing...

GPU : Finish BISR testing (OK)

SCPU: BISR testing ....

SCPU: Finish BISR testing

CPU : Cortex-A9 dual core

Media: eMMC BP0

DRAM: 1 GiB

Watchdog: Enabled

init_amp_prepare

Board: Tv010 v2 1G Board

POWER ON: AC

Cache: Enabled

Non-Cache Region: 1 MB@0x07900000

MMC:

emmc:mmc_initial(1) Sep 10 2013 17:43:47

RTD299x eMMC: 0

Device: RTD299x eMMC

Manufacturer ID: 11

OEM: 100

Name: 004G9

Tran Speed: 52000000

Rd Block Len: 512

MMC version 4.0

High Capacity: Yes

Capacity: 3.7 GiB

Bus Width: 8-bit

Extern param: MMC blk:0x7c (to 0x9000)

Factory: MMC

Factory: seq:0x9c, blk:0xe000(pp:1), size:0x1bce00 (to 0x7000000)

get_bootparam:

------------tmp/factory/bin_panel/000BootParam.h found

BOOT_POWER_ON_MODE=1

BOOT_LOGO_ENABLE=1

CUSTOM_VIDEO1_LENG=0

CUSTOM_VIDEO2_LENG=0

BOOT_MUSIC_ENABLE=0

CUSTOM_AUDIO1_LENG=0

CUSTOM_AUDIO2_LENG=0

LOCAL_UPGRADE_EN=0

boot_power_on_mode=1

get_layout:

------------tmp/factory/layout.txt found

BOOTPART=0

TAG=21

init_amp

Factory_RO: MMC

[FAC_RO] No factory_ro data in eMMC

[1;34mee read 368, 6[m

name=EEP_I2C ppcb_enum.Name=EEP_I2C, ppcb_enum.info=4

EEP_I2C=4

name=EEP_DEVICE_ADDR ppcb_enum.Name=EEP_DEVICE_ADDR, ppcb_enum.info=50

name=PIN_EEP_WP ppcb_enum.Name=PIN_EEP_WP, ppcb_enum.info=100011304

m_PIN_EEP_WP = 0x100011304

a. Eeprom_Read-macaddr is 1ca7703ebae6

[1;31m set_mac_cmd is 1c:a7:70:3e:ba:e6 [m

Panel: Use parameters in tmp/factory/bin_panel/panel.bin

Panel: sky_sdl420

panel_init_1st

$$$$ This is Local Dimming Panel !!!

Panel: ulFreq:149000000, nDPLL:157499520, Mcode:35, Ncode:3, offset:6e9

DispI : Finish BISR testing done

DispD : Finish BISR testing done

In: serial

Out: serial

Err: serial

Net: rtl8139: REALTEK RTL8139 @0xb8016000

Hit Esc or Tab key to enter console mode or rescue linux: 0

------------can't find tmp/factory/recovery

======== Checking into android recovery ====

boot_ac_on=1

(Re)start USB...

USB0: #@# usb3_phy_setting(108) +++ 20130415

#@# usb3_phy_setting(209) ---

#@# usb2_phy_s

由于篇幅有限所以只截取了一部分的打印信息，开机图像如下

冷却跟长时间试机均正常，至此修复完成。