Powerbook not waking

It will often wake ok, but on other occasions pressing a key turns the sleep light off, but the screen remains black.
Daniel Cohen wrote on :

My friend's Powerbook Titanium (so fairly ancient, and with a dead PRAM battery) has lately developed a bad habit of not always waking from sleep.

It will often wake ok, but on other occasions pressing a key turns the sleep light off, but the screen remains black.

Does anyone know the cause and cure of this. It shouldn't be a PRAM battery issue, as that is long-standing and this is new. The PB is running on mains power, and is on 10.4.9

Jolly Roger replied on :

On 2007-06-01 10:50:03 -0500, danspam@redacted.invalid (Daniel Cohen) said:

My friend's Powerbook Titanium (so fairly ancient, and with a dead PRAM battery) has lately developed a bad habit of not always waking from sleep.

It will often wake ok, but on other occasions pressing a key turns the sleep light off, but the screen remains black.

Does anyone know the cause and cure of this. It shouldn't be a PRAM battery issue, as that is long-standing and this is new. The PB is running on mains power, and is on 10.4.9

Your statement that it shouldn't be caused by the PRAM battery being "dead" is incorrect. This is exactly the type of problem failing PRAM batteries are known to cause.

Keep in mind batteries don't just die - they gradually lose their ability to maintain a charge over time. It's not a black or white thing. Also keep in mind each time you put your computer to sleep, the system attempts to store certain settings in PRAM. The system expects PRAM to be maintained by the PRAM battery until it's needed again. A failing PRAM battery will result in PRAM data corruption. <-- Read it again. It's perfectly conceivable and even expected that as a PRAM battery decays, the contents of PRAM will get less reliable over time. When you next wake up the computer, the system attempts to read the contents of PRAM. The system expects this data to be correct, and uses some of the settings it read from PRAM. Reading PRAM doesn't just fail gracefully if the battery is dead. Whatever corrupt data happens to be there is read by the system. Sometimes the system can detect that values are incorrect, and sometimes not. Due to the unpredictability of the corruption, it's a hit or miss kind of thing.

Why the aversion to replacing the battery?

Daniel Cohen replied on :

Jolly Roger jollyroger@redacted.invalid wrote:

On 2007-06-01 10:50:03 -0500, danspam@redacted.invalid (Daniel Cohen) said:

My friend's Powerbook Titanium (so fairly ancient, and with a dead PRAM battery) has lately developed a bad habit of not always waking from sleep.

It will often wake ok, but on other occasions pressing a key turns the sleep light off, but the screen remains black.

Does anyone know the cause and cure of this. It shouldn't be a PRAM battery issue, as that is long-standing and this is new. The PB is running on mains power, and is on 10.4.9

Your statement that it shouldn't be caused by the PRAM battery being "dead" is incorrect. This is exactly the type of problem failing PRAM batteries are known to cause.

OK. I just reckoned the battery had been gone so long that this could not be the cause of a new problem.

It's almost a relief to know that this could be the issue rather than something new.

Keep in mind batteries don't just die - they gradually lose their ability to maintain a charge over time. It's not a black or white thing. Also keep in mind each time you put your computer to sleep, the system attempts to store certain settings in PRAM. The system expects PRAM to be maintained by the PRAM battery until it's needed again. A failing PRAM battery will result in PRAM data corruption. <-- Read it again. It's perfectly conceivable and even expected that as a PRAM battery decays, the contents of PRAM will get less reliable over time. When you next wake up the computer, the system attempts to read the contents of PRAM. The system expects this data to be correct, and uses some of the settings it read from PRAM. Reading PRAM doesn't just fail gracefully if the battery is dead. Whatever corrupt data happens to be there is read by the system. Sometimes the system can detect that values are incorrect, and sometimes not. Due to the unpredictability of the corruption, it's a hit or miss kind of thing.

Why the aversion to replacing the battery?

No actual aversion, just Cost and hassle.

Cost because I have at last managed to find (and have now purchased) a battery at a reasonable price, most of the sites I looked at gave battery cost at around $80 for that machine.

Plus cost of getting someone to replace the battery. I might try it myself to save the cost, I do have the instructions. But there's quite a bit of disassembly needed, I think it's on the edge of what I can do, any harder and I definitely would not want to try it.

greg.r.mc replied on :
If you cannot find a replacement battery for $5 or so you are not looking very hard. I know that there are places selling them for $80 but they only sell to those who are either very well to do or not interested in spending a little time looking around for an honest deal. They problem I see is that they make themselves look like crooks when they overcharge so grossly.
Daniel Cohen replied on :

greg.r.mc@redacted.invalid wrote:

If you cannot find a replacement battery for $5 or so you are not looking very hard. I know that there are places selling them for $80 but they only sell to those who are either very well to do or not interested in spending a little time looking around for an honest deal. They problem I see is that they make themselves look like crooks when they overcharge so grossly.

that price is right for desktop PRAM batteries which seem very standard, but not for laptop ones, i think

Jan Flora replied on :

In article 1hz5nsd.ukocweu1v22vN%danspam@redacted.invalid, danspam@redacted.invalid (Daniel Cohen) wrote:

greg.r.mc@redacted.invalid wrote:

If you cannot find a replacement battery for $5 or so you are not looking very hard. I know that there are places selling them for $80 but they only sell to those who are either very well to do or not interested in spending a little time looking around for an honest deal. They problem I see is that they make themselves look like crooks when they overcharge so grossly.

that price is right for desktop PRAM batteries which seem very standard, but not for laptop ones, i think

I bought a brand new PRAM battery for my PB on ebay for $7.