Question Bad HP Pavilion Battery Cable?

[hachep]

I have tried to replace the battery in my HP Pavilion 15z-aw000. (Yeah, this is a really old consumer-grade laptop, but I'm trying to keep it going just a little bit longer and use it as a portable household terminal; the display is 1920x1080 and is still in really good shape!)

It appears that the AC adapter charges the battery: I was able to get the computer to boot up the first time after disconnecting and reconnecting the battery.

After opening up the case and connecting the battery, I was able to power up the laptop once, and even load the latest HP diagnostics (from a USB device) and run initial battery diagnostics which said that the battery had some charge, and needed calibration.

However, after that initial connection and diagnostics pass, the laptop will not power up unless the AC adapter is connected.

Further attempts to run the HP diagnostics for the battery terminate with an error saying that there is no battery. This is strange, because I can get the laptop powered up with the AC adapter connected, and then unplug it, and the laptop stays on.

Also, the white power light continues blinking whether the device is plugged into AC power or not.

Because the white light is still blinking, and the battery is connected, I am thinking that the problem is with the cable connecting the battery to the motherboard: there is enough charge to power that light, and the fact that it is blinking indicates that the motherboard has "concluded" that there's so little battery charge left that it's not worth booting up. Also, there is the indication in the diagnostics software that there is no battery connected. Might this be due to nothing coming back from the battery's management hardware on the SMBUS connection?

I am a complete neophyte with this battery management hardware, but am I at least on the right track in thinking that I should try to replace the battery-to-motherboard cable?

 

[stonecarver]

I have tried to replace the battery in my HP Pavilion 15z-aw000. (Yeah, this is a really old consumer-grade laptop, but I'm trying to keep it going just a little bit longer and use it as a portable household terminal; the display is 1920x1080 and is still in really good shape!)

So just a little foggy on if you HAVE replaced the battery.

If you have than I would at least test with a different power brick. Correct you currently can boot the laptop with power brick but it might be getting weak throwing in the extra amps to charge the battery.

If you feel your battery is getting charged test the battery with a volt meter after an all night charge. Before you boot laptop.
Put the battery in laptop let it try to boot laptop without power brick, shut down and pull the battery and get a second reading of the battery on the volt meter.

If battery volts are now low with a quick booting of laptop. It's a bad battery. If volts are still reading as a fully charged battery that yes need to turn to laptop it's self as the issue.

 

[hachep]

So just a little foggy on if you HAVE replaced the battery.

If you have than I would at least test with a different power brick. Correct you currently can boot the laptop with power brick but it might be getting weak throwing in the extra amps to charge the battery.

If you feel your battery is getting charged test the battery with a volt meter after an all night charge. Before you boot laptop.
Put the battery in laptop let it try to boot laptop without power brick, shut down and pull the battery and get a second reading of the battery on the volt meter.

If battery volts are now low with a quick booting of laptop. It's a bad battery. If volts are still reading as a fully charged battery that yes need to turn to laptop it's self as the issue.

Yes, I have replaced the battery (the original was turning into a puffy pillow.)

I don't have a voltmeter, but the battery did get charged: the HP diagnostics claimed that it had a full charge when I started trying to diagnose this situation, and the latest figure is 71%. This was after letting it charge overnight (for at least 12 hours.)

The laptop does initially boot when the battery is disconnected, and then reconnected: after that initial reconnection, when I run the HP diagnostics, the battery passes the diagnostic test, which reports a full charge.

I have been doing all of this with a new power brick.

It is after that initial battery reconnection, when I depress the power button again, that the laptop refuses to start up.

(Was trying to avoid throwing more cash at this if possible, but if I need to get a voltmeter, I guess that is what I must do.)

 

[hachep]

I should add that this is the second "after market" battery I have tried this with.

Am I having a motherboard/smbus issue?

Getting a multimeter lined up to do the due diligence on the power brick and voltage feed into the laptop, at least; testing the batteries themselves seems to be a tricky business if one does not know what each of the pins does (i.e., which pin/wire is used for communication on SMBUS, and which one needs to be pulled to ground in order to trigger the battery to "switch on" power, etc.)

It's not looking good for my old Pavilion, I guess...

Should I be considering a motherboard replacement (iffy at best) or purchasing another used laptop, e.g., a used Dell Latitude-class or Lenovo Thinkpad T-class?

 

[stonecarver]

Can you try this. If it's the battery to motherboard. Pull the battery, unplug the power brick and get a Q-tip with rubbing alcohol and clean the contacts on the motherboard where the battery mounts up power to system. See if battery starts to function like it should.

 

[hachep]

Can you try this. If it's the battery to motherboard. Pull the battery, unplug the power brick and get a Q-tip with rubbing alcohol and clean the contacts on the motherboard where the battery mounts up power to system. See if battery starts to function like it should.

Just tried that, and... well, now I feel pretty foolish.

I think part of my problem all along has been due to my failure to fully insert the battery end of the battery-to-motherboard cable into the socket on the battery.

This occurred to me after I had pulled out the cable and took a closer look at how it fit into the motherboard's socket versus how it was fitting into the battery's socket.

The battery cable for this Pavilion laptop is a ten-wire affair, part 856351-001; you can see a picture here:
https://www.amazon.com/Suyitai-Connector-Replacement-856351-001-DD0G34BT011/dp/B08XJQWRFN

So, it's a small, fiddly little thing. There's a socket for one end on the motherboard: a male socket with ten needle-fin pins nestled inside (so there's no exposed conductors to clean like there are in a ribbon-cable kind of connection.) There is a corresponding socket on the battery.

It finally occurred to me that I was not sinking the battery-end connector into the battery socket as fully as the motherboard end's connector was sunk into the motherboard socket, and when I tried to route the cable and secure it, the battery end was not making full contact into its socket.

So, I'm trying again to give it a charge (the white battery light is blinking with the power brick plugged in) and I will see if the battery starts to function properly after the charging light switches to a solid white light.

I suppose I still could have a sub-standard battery; or my previous attempts to operate with a pathologically loose connection may have so badly bungled-up the smart-battery circuitry that it can't operate correctly now...

 

[hachep]

Update:
The battery cable is now firmly plugged into its socket on the battery.

What HP does not make explicit is that sometimes it is necessary to use the power button to perform what they call a "hard reset" of motherboard battery management state.

In my case, it was necessary to do this after reattaching the battery and plugging in the power adapter.

So, it would seem that the battery-replacement procedure is approximately as follows:

1. remove the lower-case screws (there is one hidden under some rubber foot which must be peeled up)
2. go through with the fugly procedure of removing screws AND prying the lower case cover off the bottom half of the computer with a what is basically a thin nylon guitar pick; take care not to damage anything (yeah, sure, you won't break off any of the plastic tabs on that bottom case shell when you do this over and over...)
3. replace the battery, ensuring that the battery-end of the battery-power cable is plugged into the socket on the battery: no conductors should be showing if the battery-end of the cable is firmly plugged into the socket; the charging light on the power jack may start blinking white after about 15 or 20 seconds
4. replace the lower case shell onto the computer; this is another headache on its own, nearly as bad as getting the computer case opened up in the first place, complete with loud pops and snaps as you press the lower case back down into that flimsy plastic shell;
5. plug the charging cable back into its port; the LED light next to the port may still be blinking white
6. press and hold down the power button: the laptop will come on briefly and then shut back down; keep the power button pressed down for at least 15 seconds (this is what causes a reset of the motherboard's state)
7. after releasing the power button, the power LED light next to the charging port should start blinking amber, and this means that the laptop has started charging the newly installed battery

(I think I have that sequence correct...)

The important thing seemed to be to leave the power brick plugged in when performing the "hard reset" by holding down the power button for the right duration; my guess is that this allows the motherboard circuitry/programs to sense both the presence of the just-attached battery and the power-supply, and start routing power to the laptop battery.

After doing this, I was able to start up the laptop, reset the date and time in BIOS setup, and then boot up the diagnostics (from a USB drive) and the diagnostics detected the battery.

I let the laptop try to charge the battery overnight (at least six or seven hours) and then started up the diagnostics to see if the battery was still detected; it was.

So, I was able to start a power diagnostic cycle, and both the power brick and the battery PASSED, which allowed me to move to a battery calibration cycle:

1. take up to three hours to discharge the battery until the laptop shuts down
   (this only took about an hour in my case)
2. leave the laptop shut down for about 6 hours
   (during which the power LED blinks white, which indicates a "battery too low to continue without charging" state, iirc)
3. reconnect the AC power brick and wait 4 hours
   (presumably to give the battery time to re-charge)
4. turn the computer back on again

I shall post another update after I have confirmed that the fresh charge happened properly, and that the motherboard is still communicating properly with the smart battery.

LESSONS LEARNED, AND A DIATRIBE
HP could have at least published more specs and pointers about resetting the battery-charging state with that "hard-reset-via-extended-power-button" press, instead of keeping this knowledge obscured in their forums, etc.

But then people would try to replace these batteries themselves--even before HP stopped producing the batteries, and the laptop itself for that matter--instead of being pushed into shopping for another consumer-grade machine designed to break down and cook itself to death within a couple of years...

This motivated me to refresh the thermal paste between the laptop's APU/CPU and heatpipe; it occurrred to me that such a thing was way overdue, even after modest use over the past eight years. (And please don't scoff/laugh! I was forced to think about such things after building a desktop PC from components for the first time in many years...)

My eyes are now (re-)opened: consumer-grade laptops make me sick to my stomach. Heat is the eternal enemy with these things. After building a new desktop machine from component parts, I am reacquainted with such issues, and laptops have fallen in my estimation: too many compromises to make them my sole computing environment any more. This will be my recommendation to everyone I know: get a desktop unless you absolutely must have the portability of a laptop, and get ready for the many compromises.

In the future, my next laptop (if there is one) will definitely be:

• business-class
• Dell or Lenovo (kind of soured on HP at the moment)
• one-to-three generations old
• running Debian Linux, or a derivative thereof...

I'll get back down off my soapbox now.

Also, let the buyer beware: planned obsolescence is a (somewhat sickening) game many play with their customers. Forums like this are a potent antidote to this practice, and provide people with a way around or through, to avoid being ripped off. We can help each other out and also keep natural human greed in check.

I hope this helps someone else saddled with one of these nightmare-to-maintain HP Pavilion laptops. They are otherwise decent tools, if they are treated gently (pretty flimsy case and screen hinges.)