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The tho halves of the case are welded, so brute force is required to open it. The vise seems to be the best way to open power bricks, just clamp the brick near the junction point and apply pressure. once you are inside, you need to desolder a little "tab" holding the bottom shield, then you...

Quick Update: I installed a 2A fuse, powered it up and it didn't blow!, But I have no output. once I get some free time, I will see if some other component or track failed

Hello! I recently scored a couple of PowerBook 540c, together with three power bricks! When I plugged the first one, I heard a loud POP! noise coming from the power supply. I decided to open it using the vise and and after desoldering the bottom shield, I quickly found out what happened...

150uH is the inductance value recommended in the LT1070 datasheet for a 5V to 12V DC-DC Boost Converter They also recommend this inductor, but it is way bigger than the one mounted on the portable. But in the inductor's datasheet, they also specify a "C" size that matches with the size of...

I usually recommend Fluke Multimeters, but they are quite expensive, about 100€ for an entry level auto-range model. If you are on a budget, you can get a UNI-T or Mastech for less than half the the price of the Fluke. just make sure they are auto-ranging meters. some meters are also able to...

I have never opened a Macintosh Portable Power Supply (because I don't own one), but I think it is repairable. You can also tweak a PowerBook 100 PSU to work with a portable, there is a current adjustment trimmer inside. I'll send you a PM (in Italian) soon

Ciao! Why do you think that the inductor is bad? is it open? usually it is very hard to measure inductance with a multimeter. It might lead you to think that the component is shorted. From what I remember, the inductor is part of a DC-DC "Boost"converter circuit, the main chip is a LT1070...

How do you hook it up? I see two macs in the photos Do you have the software that comes with it? can you make an image? thanks again!

Amazing! What does it do?

Do you have a schematic for it? just to locate the two GLU pins. also, which pins (on the LTC1040CN) should I probe? EDIT: the switches are indeed connected to the two pull-up resistors (on the bottom of the PCB), those resistor are connected to VCC (+5V?, I checked continuity using the VCC...

A friend gave this to me, he found it in a stash of scrap boards Do you know what this card is/does? Thanks!

I moved the resistor to the two pins of the LTC1040, but the system still shows the same problem! the system does that only when powered from the right side of the connector. if I plug only the left one, or both of them, it shows no signs of life.

I soldered a 1 Meg resistor on pin 16 and 18 (on the bottom of the PCB), but it still shows the same problem

Thanks, once I get some free time I'll check the hybrid and the two caps. Yes, the unit has been completely recapped

if you need to measure a limited amount of current, you can put a resistor in series with the load and measure the voltage across it, you can then get the current flowing thru the load by using the Ohm's law.

There is no difference in powering the system with or without the cable. when the system is completely off, it draws almost next to nothing (like 0.02A), when i push both the reset and NMI buttons, it goes to 0.4A, when is showing something on the display is between 0.4 and 0.7A EDIT: here is...

the creaking sound was produced only after the sad mac. i don't know why. currently the backlight is non connected, I haven't made the cable yet (a I guess I'll need you help for that) right now I have no drives connected to it. after the screen clears, the current drops from 0.6A to 0.1A...

Thanks to snuci I was able to fix the display cable! But I am still stuck on the same problem described in my previous posts I made a video showing the issue, it's here. (it's starting to look like the Giant from Halt And Catch Fire)

Great, thanks! the connections between the flat cable connector and CN1 do match, the numbering is the same, because CN1 is designed for another type of cable (flat ribbon), it has the even numbered pins on one side and the odd numbered pins on the other. the first and last two numbers are...

That is great!, thanks! the best thing you could do is to make a table showing which pin of the Logic board adapter plug (the blue bit that goes from the white flat cable to the orange cable, first pic below) goes to which pin of the display (second pic below, the empty CN1). before making the...