Recent content by nnn

Thanks you techknight. That was what I was afraid of. Given that PMGR chip is pretty unique and surface mounted chip, I will have to leave this as non-working computer for now.

I washed the board (rinsed with distilled water as well as IPA) and let it dry for almost 3 days. When I powered it on with the bench power supply (supplying 6V and max of 1.3A), it resulted in the same symptom as before (except there is a slight noise when I turn on the computer). As...

Thanks for the detailed diagram and questions. Here are responses to your questions: 1. I used the bench power supply (picked up from Amazon) to power the computer by clipping directly on to battery terminals. I used couple of Q-tips to ensure that microswitch in the battery compartment is...

Thank you wymtb. I missed that post and that looked really promising. However, I have followed the instruction provided by Siliconinsider but no change in the symptom. Black screen and no chime.

Thank you moldy for your reply. I checked the voltage in C16 capacitor + side and it shows 5V. Also checked bottom 11th and 18th pins on the hybrid board per attached picture (pins I checked are circled) and they both showed 5V. This was done based on photo by Mc128k in one of his old post...

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...