Powerbook 170 - Chimes of Death and Garbage On Screen At Boot

[warmech]

Title really says it all - picked up a cheap PB170 that powers up, but gives the boot chime followed by the ol' two sets of error chimes. That's all fine and dandy, except there's also garbage on screen (seen below). I've done some research and checked the PSU (it outputs the correct voltage under load), removed the memory expansion, and given the board a good cleaning, but have seen no improvement. The battery was leaking, but the logic board showed zero signs of corrosion (thankfully). I also pulled the four RAM ICs to check for toasted pads and, curiously, found one on the top side of the PCB. I bodged a wire from the corresponding via to the pin on the chip, but still no improvement. Is it safe to say this board is just toast?



Additionally, if it is just toast, would the following images be indicative of a bad screen or a bad logic board? There are a couple of cheap 170s on eBay in crap shape, but otherwise working. If these are just screen issues, I may just grab one of them and swap the logic boards out. Thoughts?

 

[3lectr1cPPC]

All I can say about your 170, knowing next to nothing about troubleshooting things like this is that my 170 shows that screen for a few seconds after cold booting. (Booting after it's lost power, dead PRAM battery obviously). Of course, mine then begins to boot and act as normal, but yours isn't. Maybe something wrong with the reset/PRAM? Again, not really knowledgeable about fixing it, just thought I'd add a note that 170s do show that screen after losing PRAM info.

About the 170s in the photos, the bottom one appears to have tunnel vision in the bottom sides of the screen. Not sure about the lines, but that's definitely a problem that unit has.

 

[bibilit]

I agree, this patern is the usual one when booting.
So screen looks ok

 

[Byrd]

The PB170 will boot without RAM module (to a paltry 2MB onboard), have you tried this, and also reseat and clean the CPU daughtercard - check fuses as well.

 

[warmech]

The PB170 will boot without RAM module (to a paltry 2MB onboard), have you tried this, and also reseat and clean the CPU daughtercard - check fuses as well.

Yes to all, unfortunately. Other than the fuse on top of the CPU card, are there any others?

 

[bibilit]

Still thinking you have a broken trace somewhere

 

[AndyO]

My 180 has a similar problem. It gives a startup chime, then either the screen begins mostly black and slowly comes up, after which it boots (twice) and gets to the desktop, or it gives the startup chime, then the chimes of death. The screen remains blank however.

I have found that if I follow the reset procedure in the service manual (unplug power for several minutes, then press both reset buttons simultaneously for 10 seconds, then apply power and press the power button) it then boots.

It'll then run happily for hours, but when shut down, will always then go back to the chime and then chimes of death next boot up.

That 'garbage' screen in the first photo is what I see on my 145B for a second or so each time, and my 1400cs too, if I recall, so I don't think that's an issue. It looks like the 170 is simply not getting beyond the initial POST.