Hello, just purchased a late 2009 iMac A1311 EMC 2308 as project, it's not the first iMac I repair for hobby, but it's my first 2009 model.
This iMac don't turn on, no fans, no HD, but the first diagnostic LED in the logic board is on, so I suspect can be the PSU or the logic board the culprint, but I want to be sure, because if I change the PSU and the faulty one is the logic board or viceversa, the fix will cost more than the actual value of a working iMac of same model beause I have to change some parts like LCD cables.
I fixed on the cheap before some faulty iMac PSUs changing the capacitors, but no swollen tops on this one, so **MAYBE** is the logic board the defective one.
I followed this guides, with no success
[post|136618]
[post|280015]
[post|268443].
As far I done the folowing:
* Reset the SMC
* Checked the button battery on logic board
* Checked the voltages on PSU
* Checked the voltages on logic board
I got some weird values, so I want to know if someone know the correct voltages for the PSU and logic board power pins. I have this values on a spreadshet, hope someone can help me to figure out whats wrong with these values.
[image|1484032]
=== Update (06/15/2018) ===
@oldturkey03 thanks for your answer, I already had measured ther logic board test points, and that is what had me confused, if you look at the values I obtained, no all where what you read on the manuals, but now that I saw again the image you uploaded, realized that I was measuring the pins in the wrong order. Measuring again in the right pins, the voltages are more coherent, I can be sure about the logic board is faulty
[image|1484077]
Hello, just purchased a late 2009 iMac A1311 EMC 2308 as project, it's not the first iMac I repair for hobby, but it's my first 2009 model.
This iMac don't turn on, no fans, no HD, but the first diagnostic LED in the logic board is on, so I suspect can be the PSU or the logic board the culprint, but I want to be sure, because if I change the PSU and the faulty one is the logic board or viceversa, the fix will cost more than the actual value of a working iMac of same model beause I have to change some parts like LCD cables.
I fixed on the cheap before some faulty iMac PSUs changing the capacitors, but no swollen tops on this one, so **MAYBE** is the logic board the defective one.
I followed this guides, with no success
[post|136618]
[post|280015]
[post|268443].
As far I done the folowing:
* Reset the SMC
* Checked the button battery on logic board
* Checked the voltages on PSU
* Checked the voltages on logic board
I got some weird values, so I want to know if someone know the correct voltages for the PSU and logic board power pins. I have this values on a spreadshet, hope someone can help me to figure out whats wrong with these values.
[image|1484032]
+
+
=== Update (06/15/2018) ===
+
+
@oldturkey03 thanks for your answer, I already had measured ther logic board test points, and that is what had me confused, if you look at the values I obtained, no all where what you read on the manuals, but now that I saw again the image you uploaded, realized that I was measuring the pins in the wrong order. Measuring again in the right pins, the voltages are more coherent, I can be sure about the logic board is faulty
Hello, just purchased a late 2009 iMac A1311 EMC 2308 as project, it's not the first iMac I repair for hobby, but it's my first 2009 model.
This iMac don't turn on, no fans, no HD, but the first diagnostic LED in the logic board is on, so I suspect can be the PSU or the logic board the culprint, but I want to be sure, because if I change the PSU and the faulty one is the logic board or viceversa, the fix will cost more than the actual value of a working iMac of same model beause I have to change some parts like LCD cables.
I fixed on the cheap before some faulty iMac PSUs changing the capacitors, but no swollen tops on this one, so **MAYBE** is the logic board the defective one.
I followed this guides, with no success
[post|136618]
[post|280015]
[post|268443].
As far I done the folowing:
* Reset the SMC
* Checked the button battery on logic board
* Checked the voltages on PSU
* Checked the voltages on logic board
I got some weird values, so I want to know if someone know the correct voltages for the PSU and logic board power pins. I have this values on a spreadshet, hope someone can help me to figure out whats wrong with these values.
[image|1484032]