Re: MacBook Air A1466 - No chime, no picture, fan spinning
post mainboard code.
post mainboard code.
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Hey guys, so i have here really strange board...
These steps needs to be done to get a chime board starts to load osx but freezes with no loading bar:
1.Disconnect battery
2.P+R+CMD+OPT to pram reset
3.After only 2-7 atempts to pram reset i get chime.
4.Then i get chime allways, but if i connect battery, then boards stops to chime till i make steps from 1 to 3.
Board looked very clean, no liquid damage. Already replaced isl6259 and SMC, good known battery. Still same problem, sometimes turned off board without battery uses 0.03... -
Good Day!
History:
The board was not booting, upon opening it the fan was spinning but there is no PPVCC_S0_CPU. PP1V05_S0 was 0.550v. PP1V05_S0 Diode Mode = 0.007v , Resistance = 3.4ohm. ALL_SYS_PWRGD = 3.340v. I suspected it was a short on the PP1V05_S0, so I lifted L7630 and found the 3.4ohm short on the Load Side. I injected 1v on the rail and it was only taking 34mA. After this I returned L7630 and investigated the U7600 (TPS51916). It has VREF (1.8v) and REFIN pins. And sure enough, the REFIN voltage is just 0.550v. That is why there is ALL_SYS_PWRGD, because it thinks... -
Hi,
Since a couple a days, i try to fix 820-00165 Mobo, without success for the moment.
Measures :
1. PVRTC_G3H = 3.33v
2. RTC_RESET_L = 3.3v
3. PCH_SRTCRST_L = 3.3v
4. PCH_INTVRMEN = 2.58v
4.1 PCH_INTRUDER_L = 2.50v
5. PCH_DSWVRMEN = 2.50v
6. SYSCLK_CLK32K_RTCX1 = 0.44v
7. PP3V3_S5 = 3.3v
7.1 PP1V8_S3 = 0v (EN pin 0v)
8. PM_DSW_PWRGD = 3.4v
9. PP3V3_SUS = 3.3v
10. PM_BATLOW_L = 0.035v (3.3v battery pluged but still no power)
11. PM_RSMRST_L = 3.04v
12. PM_PWRBTN_L = 3.4v ; SMC_ADAPTER_EN... -
Macbook A1398 - had repeating loop of startup chime with no actual boot. Just startup chime, then restart, start up chime, then restart, etc. I pulled the battery and cleared BIOS. It will now power up, fans on, CPU warming, but no startup chime and no boot. I reflashed the BIOS chip but the same thing happening. Where should I go from here?06-14-2023, 11:45 AM
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Hello
Just want to diagnose bad cpu and trash this away, but hope will not
No water damage, no signs of corrosion, magsafe green then amber (no battery attached though), fan spin fast, and CPU gets HOT!! USB is 5vol present...
U1950 is ok on all volts involved...
any clues, thanks in advance!!
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