Can dead battery cause hard disk trouble?

[onlyonemac]

UPDATE:

Yesterday I tried booting my mac again. It had nothing to do with the battery/hard disk/PSU/capacitor problems-I was testing a boot floppy. I was using the double-flick to boot the mac.

I, as has already been mentioned, was trying to make a system 6 boot floppy (see post 15 June). I never managed to make that disk, but I did make a system 8 floppy which booted fine.

I did, however, notice something interisting with the hard disk. Once, it did stay spun up, but I was in the process of zapping the PRAM, so of course the mac rebooted and the hard drive didn't work. Why does the drive spin once and then not again? I didn't disconnect the power, switch the mac off, change a thing, but yet the second it wouldn't go. On the times, however, when it did eventually spin down (the "bad" startups), I heard a faint rapid "click click click click" noise from the disk, about twice a second. I don't think, however, that that's a sign of stuck heads, as it was running fine 5 seconds before.

Umm... I don't know the correct voltages for each pin on the connecter.

Look up the make and model number on google and find out what the power requirements are.

The hard disk doesn't have a model number printed on it (I just took the cover off the disk, but none of the disk platters said anything on then ). Seriously now, it just says "Apple 3.5 internal HDD", or something like that. I did notice, however, that the power requirements on the disk stated 5 and 12 volts dc. Which wire is which voltage, however, and is there an easy way to find out?

Under no load:
-Blue wire: -4.8v
-Yellow wire: 11.11v
-Orange wire: 5.27v

Under load when powering mac:
-Blue wire: -5.06v
-Yellow: 12.3v
-Orange: 5.1v

Those figures look okay, but...

PSU states 5v, 12v and -5v on sticker. Those voltages look so far out to me that I think it'll damge my logic board with that over-voltage !

[onlyonemac]

UPDATE:

Today I've tried more to fix the mac.

Firstly, I checked the voltage and current going to the drive. The currents are as expected, but the voltages are not. The 5V supply is fine, but, at the point where the drive shuts down, the 12V supply begins to rise (strange as the main PSU doesn't even supply more). If, however, I measure it under no load, it stays at 12V (i.e. it's not rising because of the current drop). Strangly, the drive continues to draw from the 5V supply even when it has stopped.

Secondly, I discovered a very strange thing. When starting up, the speaker emits a very quiet whistling noise, a bit like a jet plane. At first, it rises, then it wobbles a bit in pitch, then, at the point when the drive would have shut down (although the noise is there even without the drive), it starts to slowly lower in pitch, but seems to always remain present.

Are the two issues related or not? And what is causing the 12V supply to rise in voltage?

Please help; don't abandon my topic .

[onlyonemac]

...the 12V supply begins to rise (strange as the main PSU doesn't even supply more)...

Sorry, the 12V supply does not rise, but stays steady when the current drops. It was a fault with my meter (it does that sometimes). I would have done this as an edit, but for some reason there was no edit button.

[uniserver]

why haven't you supplied the main board with 3.6v's? sometimes i come across over sized 3.6v pram batteries i just solder wires to the +/- and then just a dab of goop and stick the battery in another place on the main board.

first things first, get voltage to the pram, if you had other macs i would suggest trying another hard drive, i'm thinking the hard drive is bad, witch is totally common, these scsi drives are old and going bad all the time.

also, try to get more then one mac, then you are enabling some trial and error, with out spare parts you cant do much.

but then you might have to change your user name

[spiceyokooko]

...i'm thinking the hard drive is bad, witch is totally common, these scsi drives are old and going bad all the time.

How can it be a bad hard drive when he can't get it to boot off floppy either? Is the floppy drive bad too? It's possible, but highly unlikely.

The most likely scenario is, (and it's been mentioned countless times and is well documented on this forum) is that the capacitors on the logic board have or are in the process of failing. If the capacitors are indeed in the process of failing, then they will not be able to filter the dc current running through the logic board and that is precisely the reason the hard disk will not spin up - it's not getting sufficient power.

The voltage outputs from the PSU look okay, the reason it's still not booting is because those voltages are getting lost on the logic board due to likely failing capacitors. Replacing the PSU won't make any difference, neither will replacing the hard disk.

I accept the OP doesn't want to accept this as the reason, but there is no other logical explanation as far as I can see.

[onlyonemac]

...i'm thinking the hard drive is bad, witch is totally common, these scsi drives are old and going bad all the time.

How can it be a bad hard drive when he can't get it to boot off floppy either?

It does boot off the floppy-I once said that it was "Sad Maccing", that was my bad boot floppy, not the drive. Floppies are the only thing that give my mac life!

...the reason the hard disk will not spin up - it's not getting sufficient power.

Disk does spin up, the problem is that it spins down again before the mac can boot. Please review the boot timelines posted on the 10th of June.

The voltage outputs from the PSU look okay, the reason it's still not booting is because those voltages are getting lost on the logic board due to likely failing capacitors. Replacing the PSU won't make any difference, neither will replacing the hard disk.

Um... there is no voltage lost on the logic board. Please review the voltages posted on the 1st of July-ignore, however, the statement of the 12V rise, as this was a meter error.

[spiceyokooko]

Please review the boot timelines posted on the 10th of June.

No thanks, I'm done with this thread.

I've tried to help you as much as I can but you're not listening to anything and think you know best - good luck with getting it fixed.

I know when I'm wasting my time.

[onlyonemac]

UPDATE:

Over the past few days, I've found out more information which may or may not help to diagnose the problem.

Three or four times, the hard disk has spun and and stayed spun up. The mac booted quite fine, and, once running, there were no problems. I made various system backup floppies, which I can boot it from, and it did that fine. The disk was like it always was. I did some warm restarts and, as long as the disk kept spinning, it kept working.

But, as soon as I switched the mac off, only five seconds later the disk would not stay spun up. On the times when it doesn't work, there is a quiet "click-click, pause, click-click" noise coming from the drive, about twice a second.

Why does the drive sometimes work perfectly and then not at all? And what is making the feint clicking noise?

[mcdermd]

I think you know the answer by now.

[IPalindromeI]

If it's clicking, s***'s dead. Drive is a goner. Replacement.

[onlyonemac]

I think you know the answer by now.

I'm not going to waste my time doing something without knowing if it's going to work. Something which will work 100%-fine, but not wasting money on something which doesn't actually help in the end.

If anyone can proove this to me, then maybe I'll consider it. But, for as long as there's an "if"-no go. I am prepared to keep my mac working, but my budget is tight, so I can only spend money on things that'll solve the problem for certain (once you've wasted money on something that doesn't work, you can't get it back).

[Cory5412]

Capacitors, even whole power supplies, and whole hard drives for these old things are generally fairly inexpensive. If you can't afford to buy a new PSU (or a recapped one) for your machine in order to troubleshoot this issue, then you should sell or recycle the machine and use a more modern machine which is less likely to have little electrical components failing.

If you're not willing to troubleshoot this issue (and unfortunately for many people starting with their first old Mac, who only have one Mac so far, or who are reducing their collections) this does often involve "buy another Mac" or "buy some spare parts" then I don't see how it'll be possible to make a determination as to which part is failing (presuming it's only one) and suggest a specific course of action.

As IPalindromeI says-- that shenanigans is dead. The hard disk almost certainly needs a replacement, and even if you buy one and find out it is the power supply, having a spare hard drive is never a bad thing.

[Bunsen]

Something which will work 100%

No-one can give you the guarantee you are looking for. You've been given the best advice this experienced community has to offer. Either try it, or don't. Asking the same question over and over isn't going to change the answer.

[onlyonemac]

Firstly, sorry about the late reply-I've been unwell, so I was keeping off the family computer so as not to "infect it with viruses"!

Could this be related?

I have been running off of a RAM disk from time to time. It works quite well, and I can run my favourite programs from floppy. That was until the morning two days ago .

I switched it on, waited for the hard disk to click and spin down, then popped my floppy in as usual. It started, the RAM disk loaded, then as soon as the RamDisk INIT was supposed to eject the floppy, the machine froze. So I reformatted the boot disk using an image of a good version (I assumed this one to have become corrupted-I change settings sometimes).

Then, of course, the hard disk decides to go, so I use that insted (without testing the boot floppy yet). I load the program-no problem. I open the file (file's not corrupt-tried other files too, and they also had a problem) and the program quits/crashes. Afterwards the Finder's menu bar is all greyed out, and when I open a menu, I get all sorts of red, green and blue smudge underneath!

Could these both be signs of RAM trouble, and could that be linked to failing capacitors?

Even stranger, it booted fine from the RAM disk, and loaded the file, soon afterwards, and hasn't shown trouble again since then .

[techknight]

REPLACE The capacitors... period... story ended...

[onlyonemac]

REPLACE The capacitors... period... story ended...

I have now. It fixed the RAM problem, the sad maccing and the whistling through the speaker. However, the hard drive still spins down after power up, and it doesn't seem to ever work (although only time will tell). Once, it did the other thing where it would play half the death chime before playing the happy chime and asking for a boot disk (I don't know why it's doing that-anyway).

How could I fix the hard disk trouble? (So far I've tried a PRAM battery and a recap)

[mcdermd]

Get a new hard drive.

[techknight]

if there is data on it you can quickly perform the head un-park trick, but other than that you toss it and buy another one. I recommend the older IBM SCSI drives. I never had one die. I can only say the opposite on the new "deskstar" series though.

[onlyonemac]

Unfortunately, I tried that the other day and my clumsy finger scraped the top platter .