Powerbook 140 Issues

[Johnnya101]

Hi all,

Got the charger for my 140. Plugged it in and pressed the button...

Bongs, boots to dark blue screen, hard drive spins up, everything shuts off, black screen, hard drive spins up, speaker clicks, continues.

Caps?

I removed the battery and tried again. Same thing.

 

[Unknown_K]

Have the correct voltage and amperage power brick?

 

[Johnnya101]

Its a "Macintosh Powerbook AC Adapter"

Output DC 7.5 V

2.0A

Someone told me this was the one I needed.

 

[Unknown_K]

If it is the same one as the 170 unit they are unreliable junk.

 

[Johnnya101]

It is the same. I measured output voltage and got 7.85 V. Reset the PMC or whatever its called, same thing.

Why are they junk? Any replacements that are new or more reliable?

 

[maceffects]

If memory serves they have capacitors in them that are no subject to fail. However, cheap aftermarket ones have their own issues. As long as the output is right then it shouldn't be an issue with the power adapter.

 

[Johnnya101]

Im going to stick with this one for now. 7.85 V output vs the supposed to be 7.5 V shouldn't be causing this, correct? Within .5-1 it should be okay?

 

[Unknown_K]

Voltage under load is what you need to measure, which is hard to do. I think I rigged up some SONY power supply with the correct tip for my machine (have a dead Apple PS I should pop open and replace the caps someday).

Remove the HD and try booting (since that would be a significant load on the system).

 

[bibilit]

Your problem is coming from the display, not from the Logic board side.

Psu voltage is correct with no load.

All those units (140/145/170...) have the same problem, the back of the LCD is populated with capacitors leaking all other the board.

9 x 3.3 uf 33 volt and two 100 uf 25 volt IIRC, two small caps are also present in the inverter board (4.7 uf / 16v)

I have repaired a lot of them, the display will have a blue/grey hue until the caps have been removed and replaced.

 

[Johnnya101]

Ok, thats what I figured! I thought it would display something, but I guess not. I knew it had something to do with caps when I found out changing the brightness or contrast did nothing.

Ill take it apart once Unknown gets the caps in for recapping. The hinge needs to be heated up and melted together, and the thing needs a deep clean.

 

[Rajel]

Ouch, yeah the screen caps on these are baaaaaadddd
Every one of the caps around the LCD on my PB160 was leaking onto the pcb. Swapped out and good as new.

 

[Johnnya101]

Rajel, are the caps the same you think?

 

[Ferrix97]

If you have a dark screen with no (or very little) contrast control it's almost always the caps.

As for the ticking noise, it's possibile that the head inside the hard drive is stuck.

I have videos that show how to solve both problems on my Youtube channel

https://youtu.be/9YhiiOUWu64?t=4m7s

https://youtu.be/XP-fWaDbv5s

The power supply will need new caps soon, but I don't think it's the problem this time.

 

[Johnnya101]

Hi Ferrix,

Theres no clicking. The hard drive is fine, and spins up and down. The SPEAKER clicks. Like an obvious speaker noise...

The power supply will need recapping too? Will that let it be reliable from now on? Can you even open them without damaging them?

 

[Rajel]

The caps are likely the same or similar. Ferrix''s videos are what I used as a guide for doing my 160.
The speaker does click when the audio system kicks on and off, it's off most of the time and turns on only when playing audio.

 

[Ferrix97]

That ticking coming from the speaker might be the power supply that turns on and off (with the old caps it's pretty unstable). But in this case the hard drive should stay off or follow the ticking.

I also have a (quite old) video on my channel where I open the power supply by applying pressure on the lower side to crack the two halves clean.

https://youtu.be/LxG3NO0jy9U

If the board is cleaned properly and all the capacitor are replaced with good quality ones, it'll probably last forever.

If you don't wan't to deal with all of this, you can also pick up a Playstation One power supply and change the connector at the end. They are more reliable and easier to obtain.

Unlike the Macintosh Portable, PowerBooks have a moderately robust power supply circuit. I've seen them run with 12V power supplies without issues (as they have the same plug and most eBay sellers and such don't check the specs), they also have minot reverse polarity protection in form of a diode (that might short).

 

[Johnnya101]

Eh sounds like it would be easier to send this off to the person recapping my board too, I like t keep it somewhat original. Besides, best to fix it then abandon it.

It kina sounds like that shutting off, but it shuts off right at the same time each boot... So.... I don't really know. I thiink just recap everything.