I have recently got a Macintosh portable (M5120) that did not come with a hard drive or a correct power adaptor (It did come with a original battery but it outputs 1.5V so it appears to be dead).
Previous owner told me that he used one of his existing plug to power it up and it would sometime boot up to a disk with a question mark and other times, it would not boot. Unfortunately, I found out that he used a plug that outputs 24V and 1.2A.
I recapping all capacitors (some caps showed sign of minor leakage but I didn’t notice any damage to traces) then used bench power supply to power the computer from the battery compartment pins (6V with max of 1 amp). When I turned on the computer, I get a black screen and no chime (floppy drive is disconnected). When I turn on the computer with the floppy drive connected then it would make a single click sound (I believe sound is coming from the speaker) and black screen. Symptom is the same whether I connect the 9V battery or not. When the computer is powered on, the power supply shows 6V and 0.17A.
I also replaced a mosfet (Q1) with another IRF9Z30 as I thought it was shorted but replacing it had no effect.
I read number of mac portable repair posts but nothing with the symptom that I am seeing. Could this be problem with the SWIM chip or the Hybrid board?
Just thought to ask the forum to see whether there is any hope in getting this computer up and running.
Previous owner told me that he used one of his existing plug to power it up and it would sometime boot up to a disk with a question mark and other times, it would not boot. Unfortunately, I found out that he used a plug that outputs 24V and 1.2A.
I recapping all capacitors (some caps showed sign of minor leakage but I didn’t notice any damage to traces) then used bench power supply to power the computer from the battery compartment pins (6V with max of 1 amp). When I turned on the computer, I get a black screen and no chime (floppy drive is disconnected). When I turn on the computer with the floppy drive connected then it would make a single click sound (I believe sound is coming from the speaker) and black screen. Symptom is the same whether I connect the 9V battery or not. When the computer is powered on, the power supply shows 6V and 0.17A.
I also replaced a mosfet (Q1) with another IRF9Z30 as I thought it was shorted but replacing it had no effect.
I read number of mac portable repair posts but nothing with the symptom that I am seeing. Could this be problem with the SWIM chip or the Hybrid board?
Just thought to ask the forum to see whether there is any hope in getting this computer up and running.