PowerBook 540C Problem

[blackbird]

I have a blackbird that stopped working on me. Everything was great and yesterday i started it up and nothing. No start-up chime and black screen. I reset the power manager and nothing. Does anybody have a clue of what might be wrong? Thanks.

 

[wally]

Check if the power connection block on the right rear to the AC adapter has a cold solder joint by pressing and wiggling the connector while trying to start up. Also wiggle and really seat the IEC AC cord into the adapter brick, there are a few particular power cords in my house that are a loose fit on the power pins of the brick and fake me out sometimes. If you have two adapters swap in the other and try it. My three blackbirds will start from AC alone with both batteries removed, and even if I fake out the cover closed switch to pretend that it is stuck. If you have test gear hold the open power connector end slot down and see if you get around 14.3VDC across the top pair and 16.6VDC down the right pair. Then if necessary pull the keyboard and check/clean/resecure the flex connections. If still no joy you might consider a keyboard swap from your other blackbird as a test.

 

[Forrest]

Could be a dead PRAM battery. The computer will startup with a dead PRAM battery, but the screen brightness and contrast default to 0 - you need to use the buttons to increase both on bootup.

 

[blackbird]

It's some kind of internal issue. I've tried two different AC adapters that work and nothing. I know the computer is getting power from the adapter because it actually turns on (I can hear it and the CAPS LOCK key lights up). However, I don't get the chime or anything. It's not the HD cuz it doesn't have the blinking question mark it's just a black screen. I tried increasing the brightness but nothing.

Anyone have some other suggestions?

 

[wally]

Swap hard drives with your other blackbird, and see what happens on each!

 

[The Macster]

It's some kind of internal issue. I've tried two different AC adapters that work and nothing. I know the computer is getting power from the adapter because it actually turns on (I can hear it and the CAPS LOCK key lights up). However, I don't get the chime or anything. It's not the HD cuz it doesn't have the blinking question mark it's just a black screen. I tried increasing the brightness but nothing.

The dead Duo that I have is a bit like this - the caps lock key lights up but there is no sound, no chime, no life from the screen - I thought at first it must be a power issue, but hooking up an external screen and floppy drive showed that the machine is actually working, just someone's had the hard drive out of it and the screen must be dead. So I would try an external screen to see if your PB's screen (or the connection to it) is dead; however looking at my 520 it seems as though the display connector is a very weird one, so you may well not have the correct adapter for it.

 

[blackbird]

I swapped HD and nothing. Now I'm going to try swapping the screen. I think I have a spare one around. Wish me luck. In the meantime please keep the suggestions coming. Thanks.

 

[wally]

If the speaker is turned down my 540c chime does not sound. If it was just a dead display that was not dragging down the rest of the machine you should hear one heck of a lot of disk seeks as the rest of the machine boots up independent of the display. Once the machine is fully up you can turn it off without a working display just by hitting the on/off power button once and then hitting return to select the default. You are lucky to have another similar machine to do swaps, the processor/memory swap is an easy one to try. Just be sure to take the usual static electricity precautions and touch metal on both machine grounds before removing and moving parts from one machine to another, and if you have to set parts down somewhere grounded foil or conductive foam is best. In swapping displays go gently on the plastic trim parts, it is easy to break off the various little tabs that hold everything together. If you do break off pieces save them, they can be reattached by a welding or adhesive process later. If just the backlight is faulty or is turned off, I can see the screen displaying the desktop of my 540c (just barely) if I hold a 60W desklamp 45 degrees to the side and also place my eye near the lampshade and look at light reflected back towards the lamp.

 

[equill]

The backup (not purely a PRAM) battery of the PBs 100 and 500, at least, is intended to have power enough (50-odd mAh) to allow graceful exit to sleep, and maintenance of the contents of RAM for up to 24hr, when the main battery runs out of puff. For this purpose they are rechargeable, and remarkably rugged. I've had a dead-flat backup in a PB 160 recover full function after an estimated 12 years off the AC adapter.

But there's a catch. (There always is.) Backup batteries do not begin to recharge before the main batteries reach nearly full terminal voltage. (Nota bene: not full capacity, so if even a battery with 30-50% of original capacity reaches about 7V (100s) or 10V (500s), the backup can charge. Then the four-fingered salute No 1 can be effective in resetting PRAM and restoring the notion of startup to the PB. How to get the backup to charge? Leave the PB on the adapter for anything up to a week, checking startup ability at intervals. This certainly works for the NiCd 100s, and can usually work for the NiMH 500s, despite the interference of their stupid intelligent batteries. And no, it doesn't work if the main battery is left out.

For the 500s remember also four-fingered salute No 3: control-option-command-power. It stops them instantly, and not gracefully as power first, count five, then return, does. In case you are wondering, four-fingered salute No 2 is shift-option-command-delete, inviting Start Manager to bypass the usual startup hard drive in favour of something else (eg a CD-ROM drive) on the (usually) SCSI bus.

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[blackbird]

I swapped out the daughter card and the RAM Module and that seemed to do it. So I guess the memory was corrupted. Thanks for all the advice. javascript:emoticon(':beige:')