• Updated 2023-07-12: Hello, Guest! Welcome back, and be sure to check out this follow-up post about our outage a week or so ago.

More PB180 trouble

So I fixed the 180’s short circuit issue yesterday, but it is still not booting with no sound and only staticky garbage lines on the active matrix screen. (this is after powerring it up in the chassis as well). Any possible causes?5BEE27DD-8640-40C1-830D-B559A29F562F.png
 
This only happens after plugging in to a known good AC adapter, then pressing the power button. The reset button usually rearranges the line pattern (it tends to “move down” a few pixels) and the interrupt button does nothing. I have removed the PRAM battery, as I have read that 180s boot without one.
 

desertrout

Well-known member
Thanks for detailing your repair journey! These 180's are great machines, imo.

So, a few simple things pop to mind:
- perform a power manager reset (let system sit without power for 3-5 minutes, then press and hold the reset and interrupt buttons at the same time for 5-10 seconds, then reconnect PSU and boot)
- verify all inter-board connections are solid
- verify the display cable is good (continuity check) and seated well
- ensure all corrosion / residue is removed (I noticed in the other thread a lot of battery crust on the main board - may need a vinegar scrub or bath)
- is the grounding strip at the battery interconnect in place? I noticed in the other thread that the rest of the battery interconnect was missing, and memory serves that a solid ground connection there is important...
 
Hi, thank you very much for the follow up! I've tried the steps above and unfortunately there seems to be no change in the behavior. I've removed the grounding strip for this minimal "bench test" (so as to rule out corrosion around/on it), but I have tested the PB fully assembled as well. Wiggling boards, etc, checking continuity, and reassembling the whole "apparatus" has no effect either.

The power supply (EU model) is not refurbished but works; I have measured the voltage and it also works perfectly with a PB150 for hours on end. If I might add, the display contrast and brightness sliders are fully functional. Other things I've done include removing and replaced the floppy drive w/ its flex cable, and installed/uninstalled a RAM expansion card.
 

desertrout

Well-known member
Sorry for the late response... I haven't been at my desk much. OK - which power supply are you using? If it's the ADP-17AB 'Low Power' model intended for the 150 it may not have enough jam for the 180 - Apple ultimately recommended the 24W model (7.5 / 3.0A, M5652), or at the very least the M5651 that came with it.

But I'm not convinced that's the issue. Could be a bad display, could be a bad interconnect board or cable... it's usually at this point you need to break out the oscilloscope, but we don't have schematics for these models... I wish I could provide more direction.
 
Hi, just got back and did a little more testing, unfortunately without success. I've got a 3A adapter that originally came with a PB170.
 
Top