PB 160

[itownian]

So I just received this 160 as a castoff from a friend's closet. It is my first pre-G3 mac. I am pretty psyched to get it working.

The boot chime happens. Repeatedly. With the machine turning itself off and on.

Would anyone who's seen this issue before care to comment? Any advice would be greatly appreciated.

 

[MacMan]

This seems to be the day for it! I'm going to refer you over to a thread on the RetroMacCast website that has been covering exactly the same problem with a 165c (architecturally very similar to the 160): (link)

 

[Byrd]

Pull the battery out, and leave it plugged in with mains power on for a couple of hours.

I've come across a few PB 1x0s like this that haven't been used for several years, seems to be an issue with the battery having too low a voltage to charge and "kick over" the Mac at startup. Once removed, and the PRAM battery charged for a little while, you can plug the battery back in.

If this fails, time to take her apart, and reseat the RAM and processor card.

JB

 

[equill]

A quick invitation to your PB 160 to re-savour life must include resetting the PMU. Remove the AC adapter (always from the PB first, and then the wall outlet), then the system battery, and then allow the PB some 10min. of self-reflection and time to reset its logic board.

With two toothpicks or paperclips, simultaneously hold in the two recessed (interrupt and reset) switches, on the rear beside the power switch, for 10sec or so. Then connect only the AC adapter (always powered on from the wall before connection to the PB) and see whether it will boot. If it does, leave the PB connected to the mains after shutdown, but now with the system battery in place. In this way you ascertain the PB's ability to boot without hindrance from a poor battery, and then give the battery a chance to recharge (for at least 24hr), and when the system battery reaches close to full voltage (7.5VDC), the internal backup battery will begin to recharge.

Nail this to your 'frig. door for future reference.

de

 

[itownian]

Okee, so this has solved the problem of the repeated restart. But it never gets to the smiling mac. Chime, and then endless blank screen. The hard drive whirs and clicks softly for about a minute and then steady blankness. Perhaps I should now reinstall OS 7.1? Maybe even a new hard drive? Hmmm.

 

[tmtomh]

My guesses: a loose connection inside the PB, or else a dead HD.

M

 

[equill]

You get a chime, so POST is successful. What form does the 'endless blank screen' take? No activity at all? Grey raster? Pointer present or absent? You hear (the PB 160's IBM drive cannot be missed when it spins) the HDD, but do you hear read activity? Are the contrast and brightness sliders hard left? Have you a boot Disk Tools floppy disk prepared and ready? You rilly, rilly orter poke around these forums to learn about the startup sequence of 68K Macs, the milestones and when they are reached, what Happy Mac and Quizzical Floppy are on about, and what you need in the way of larger hammers and big guns for troubleshooting. Go on. You know you want to do it.

de

 

[itownian]

The screen now faintly has steady lines at the top and bottom each approximately 4 (or6) pixels from the edge. There are also grid-like cones within this short screen border at top and bottom. Seven narrow points and wider ones between. And the screen flickers faintly and only intermittently with pale lines across it's main body, showing a six by four grid. Is this the "grey raster?"

I hear read activity in the drive.

The sliders are indeed hard left.

I do not, however, have a boot Disk Tools floppy. Perhaps I'll go look for such. . .

 

[itownian]

Okay. So now I have a set of bootable install floppy disks (with disk tools). I just don't know how to boot up from them! My mac career started with CD booting back in 1998. . .

How can I boot from these disks?

 

[register]

The sliders are indeed hard left.

Then you might try to slide both sliders hard right. Both sliders hard left turns out the backlight and sets contrast to minimum. Try to set the backlight to max. intensity and fiddle with the contrast slider. Some of these machines need to get readjusted after some minutes of use, or the screen contents become unreadable.

The PB 160 contains a 3 Volt Lithium cell, soldered onto the little board containing the speaker and backlight controls. This battery will be dead, most likely, causing some kind of amnesia when disconnecting the power adapter and the removable battery. After you managed to boot the system successfully, you might consider to fix this issue. The machine is very well engineered, but please make sure to take precautions to avoid damage through electrostatic discharge. The CMOS devices on the board do not like to be exposed to more than a very few volts. If you want to use a multimeter, make sure to use one with a maximum test voltage around just 1 Volt. Some multimeters use higher testing voltages, and might fry the motherboard just by checking a line. I verified this on a motherboard and a backlight control board as well, sadly.

But before attempting to dismantle the PowerBook (with a tutorial), get it up an running. Shut the computer down, put the disk labeled "Install me first" into the floppy disk drive and switch the computer on

 

[equill]

The backup battery (it is more than a mere PRAM-maintaining battery) that I mentioned above is on the interconnect board, as register also noted. It is a secondary battery (ie, rechargeable), but it may very well be depleted. Take heart, however, for my first 160's BU battery had been uncharged for upwards of a dozen years, but still recovered when the main battery reached roughly 6.8V, so you too can do it. The BU batteries are rugged. They have to be, because their main job is to shut down the PB gracefully when the system battery runs out of puff, and even then they are designed to maintain the contents of memory for up to 24hr while you get to a mains outlet or replace the system battery with a charged battery.

The 160 has an FSTN (passive) display. Set contrast to full (hard right), and then gradually move brightness to the right. At the first sign of a desktop, stop. (One of the weird screen effects may indicate that the top-of-display menu bar is present, which is a good sign.) Gradually decrease contrast to find the black screen point, and then increase contrast again to restablish the desktop image. Fiddle incrementally with contrast and brightness to optimize the image.

The foregoing assumes that the PB has booted to the desktop. With an unknown hard drive this may not be certain, so a Disk Tools floppy is a better tool for this work. The DT floppy can also check your hard drive for condition, reinitialize it for installation of a new System, and so on.

The base RAM of a 160 is 4MB. If that is all you have (ie, no RAM expansion card plugged into the processor daughter-card) you don't have much room to move, but System 7.1, or an installation of 7.1.3 retrofitted with elements from System 7.5, can work very well in 4MB. The weirdo screen effects that you see may very well be abolished by breaking, cleaning and remaking the daughter- to mother-board contacts, the inverter to display connection, the RAM expansion card to daughter-card connection (if you have an expansion card), and so on. B&W rather than 4 or 16 greys may be set at the moment, and that will exacerbate the weirds. Pay special attention to the seating of the ribbon cable from daughter card to the upper case half. Its 'memory' of past folding can pull the connector out if you are not on your guard.

The Disk Tools floppy should also boot the PB. Either insert it before startup (after resetting the PMU, as above), or immediately after the POST chime. The floppy drive is polled before the hard drive as a potential boot volume. If you can get to the desktop this way and 'see' the hard drive also mounted on the desktop you are well on the way to success.

de

 

[itownian]

I have received my OS 7.1 floppies. The disk tools have failed to boot the machine. The PMU reset procedure as well, have failed to allow the boot from floppy. I have a new battery and power brick. Currently I am mucking about, looking within the hardware.

I am at a loss, however, for how to proceed. I'll attempt to reseat the connectors and boards.

It sure would be pleasing to play with this thing, and make it boot, etc.

Advice is truly appreciated.

 

[tomlee59]

Many possibilities:

1) The floppies are at fault. Remember: The 160 needs a System Enabler (131, according to Apple) to boot from 7.1. If your set of floppies does not include this enabler, that would be a problem.

2) Your floppy drive is at fault.

3) Some mysterious hardware failure awaits discovery.

 

[equill]

Have you asked your friend whether the PB was working when it went into the closet? If it was not, whether the fault was known? Had it then, or since, been an organ-donor? There is so much that could be a terminal fault that no-one who has not the PB in his hands could guess at. The advice that you have received so far is premised on the idea that the PB is capable of working. If you can get hold of the Apple Service Source document used by AASPs of the time you can at least discover whether all of its parts are present, and whether there are gross disabilities that you haven't yet reported. Does the floppy drive sound active with a disk in it? If it doesn't boot the PB, how are you getting the floppy disk out?

Are you still getting the repeated POST chime with the new battery and AC adapter? Are you getting any chime now? If the PB does not have an essential component that you do not yet know to be missing, you have a ready-made reason for its present behaviour. If the daughtercard or the inverter board, as examples, are missing, you could speculate from the outside forever as to the cause of the problem. That is why you must look at the PB's insides and tally its contents, check the connections, and close it knowing that everything is mechanically ready to go, if not electrically. Your foray inside must also include an inspection of condition: general cleanness and freedom from corrosion and gunk, especially around the battery contacts in the battery bay and on the MLB. Dead shorts and missing traces contribute nothing to the PB's function.

Having given your PB a working battery and adapter, a valid startup volume and a PMU reset, but not been rewarded with startup, you are now faced not with troubleshooting but with rescue from disaster. As the bloke on the spot, only you can see what may be wrong, so you have to get the data to recognize the problem and formulate a response. We at a distance can only encourage you to persist until you are successful, or reach a terminal impasse.

de

 

[equill]

tomlee59

A propos of nothing, have you only recently taken to showing your locus vivendi, or do I misremember that the field was formerly blank? I'm not suggesting that the locus is unexpected but that I noticed its presence only a moment ago.

de

 

[tomlee59]

Equill -- It is indeed a recent addition, made in response to a request over at the Trading Post. As for vivendi, it's perhaps more like nerdendi...(or is it a first-conjugation verb? I defer to you, sir!)

 

[itownian]

Equill - I suppose I'll be persisting.

The repetitive restart trouble has cleared. That seemed to have been related to the PMU and/or faulty power supply brick. The startup chime now brings grey death. The floppy drive does make some clicks and whirs for the first minute or so, but nothing further. I took apart the 'book earlier and found a pristine looking situation, like new. The previous owner was an older Cornell prof., who very likely was quite careful and conservative with his little computer of sixteen years ago. The display cable is quite supple and correctly connected; I was too cautious to unseat the daughter card from what I suppose is the mother board. I don't know where to look for the RAM on the board, and could not find any information by google.

tomlee59 - Thanks for the system enabler clue, I'll see what can be arranged regarding that. And the floppy drive, of course. (and other fun hardware failure!) Suppose I'll be needing a parts machine. ;-) And to interject (latinus nerdus sum): vivendi is the gerund, living/nerd-ing...

Cheers!

 

[equill]

With the bottom case half in the position that it would be when fully dressed, the daughter card attaches to the MLB on the left side of the PB. A RAM expansion card (vide supra. Now see what you Latinists have started ...) attaches to the DC at its rear edge, just inboard of the video-out port and video-up ribbon. If you don't see this third plane or layer, and there is an empty connector next to the video-up connector, you are blessed with only the on-board RAM: 4MB. Not fatal, but mildly inconvenient. There is a complete guide to Mac RAM (as at 2000) here. It is not the latest, but the penultimate. Natheless, the info. about PB160 and friends is adequate, as is the diagram. As for the familial relationship between cards in a PB, take heart. The 165c has a cousin card for RAM expansion.

The enabler can be found on the second floppy disk of System Update 3 (for System 7.1) with all other enablers then known to mankind. Iterum vide supra.

de

 

[tomlee59]

And to interject (latinus nerdus sum): vivendi is the gerund, living/nerd-ing...
Cheers!

Around these parts, "to nerd" is a valid infinitive, so "nerding" is really what I meant. Arma nerdumque cano...