Re: Need help on Macbook air 1466 with board 820-00165-A. Doesnt turn on
Thanks. you are right. il fix capacitor first and get voltage readings then if i dont get standard reads, il have the U7501 replaced. will keep you posted. wil get the cap 2days from now. hope nothing was affected after my getting voltages witbout c7400 installed
kitt7
New Member
Last Activity: 02-19-2019, 09:13 AM
Joined: 02-03-2019
Location: Pasig
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Re: Need help on Macbook air 1466 with board 820-00165-A. Doesnt turn on
Thanks again Piernov. So I checked the voltages again this time. Pls note that C7400 is not attached thus i dont have any bypass cap before the Vin of U7400. The ff are the voltage reading i got:
For U7501:
Vin (pin23) = 8.55 volts - OK
VREG5 (pin29) = 2.5 - 4.95V (erratic - going back and forth, etc)
VREG3 (pin22) = 3.28V
VREF2 (pin13) = 0.3 - 1.8V (erratic - going back and forth, etc)
EN (pin12) = 0.6 - 2.8V (erratic - going back and forth, etc)
EN2...Leave a comment:
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Re: Need help on Macbook air 1466 with board 820-00165-A. Doesnt turn on
Thanks Piernov and Gimi. I removed C7505 (capacitor nearest the VREG5 pin 29 of U7501). Problem still shorted to ground. Then I removed C7400(capacitor of U7400), NO MORE SHORT to GROUND!
I tested via multimeter the C7400 disconnected and it really shows the capacitor shorted. Thanks very much Piernov for your help!
Now I have to find the capacitor c7400 (10uF 10V 20% x5R 603) to replace it. Is it ok for now to check voltages or turn on the laptop (without the C7400) while im still looking...Leave a comment:
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Re: Need help on Macbook air 1466 with board 820-00165-A. Doesnt turn on
sorry i meant my mac laptop doesnt turn on im using magsafe 2 power adaptor 45W designed in california. assembled china model A1436 (as per writings in the cover). i think it is original because we bought it at apple store.
SMC_PM_G2_EN shows 3.3Volts, Voltage across C7505 or PP5V_S5 shows 0.16volts. i checked the resistance across the c7505 (capacitor connected) it shows 2.9ohms. i also used continuity checker and it gives beep sound.
I was also able to check other pins like P5VS4RS3_EN...Leave a comment:
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Re: Need help on Macbook air 1466 with board 820-00165-A. Doesnt turn on
May I iknow if you have datasheet of TPS51980A. I cant seem to find in the net. thanks v muchLeave a comment:
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Need help on Macbook air 1466 with board 820-00165-A. Doesnt turn on
Hi Everyone, I need help on my mac 820-00165-A. Here is the problem:
1. Mac does not turn on when power key pressed. Adaptor shows green then amber and stuck to amber. I tried to reset SMC using the keyboard techniques. Still it doesnt power up.
2. Prior to this, i plugged the MAC at 220v power outlet while it is off and took around 2-3 days plugged in at OFF condition without anybody using it for 3 days. The repairman i talked to said that it is wrong to leave the laptops OFF and plugged in and charged for very long time.
3. As i know a little about... -
Re: New Members - please post your introductions here
Hi there!
Im Kitt. a newbie in electronics. I just got challenged to repair our mac laptop because it got damaged 2weeks ago.
Looking forward to be able to contribute and help and be helped also.
More power to you guys!Leave a comment:
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Re: Macbook Air 820-00165-A schemati and boardview
thanks again for the schematicLeave a comment:
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Re: Macbook Air 820-00165-A schemati and boardview
Thanks for the schematic and boardview philsurmac
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