Another HP playing up at a crucial moment.

[Loose rivets]

It's an old one, but to pick this moment! Karma again.

W7 on HP Pavilion 640n

1.5 gigs


It's been a good old workhorse, but just after the wife's Laptop failed, we came in to find the PC cycling with fan on full. Drive lights, including both CD/DVD, sequencing in turn and generally looking like it had gone scatty.

Powering down and rebooting, it seemed to be okay, but then I noticed it came on when the power was turned on in the mornings. Always, it's had to be started with the blue button. Power button contacts seem to be working normally.

Can't see an option in the BIOS to account for this, but really under stress now with the wife leaving for the UK - needing to print tickets etc., and this is the hub.

Worse, it shuts down several times after starting. A blue screen full of text shows something about memory being dumped - I think. Too quick to really see much. Tried to photograph it, but never does it when I'm waiting.

I'm open to it being two issues. But it would be an incredible coincidence. The later being malware of some sort? But why would it get better after a while?

I have security essentials and that's it.

This AM. BIOS battery replaced.

Changed the memory around. I gig in 0 and the half gig in slot 1.

Changed the half for new, but don't have another 1 gig. (Too expensive cos it's old tec.)


Cleaned out and fired up, but just the same.


Any ideas would be welcomed.

[hellsbrink]

Take battery out, power up on mains only, let us know what happens.

[rgbrock1]

Loose:

Seeing the machine is rather on in the years have you checked the insides for dust bunnies/dirt bombs?

Our PC was exhibiting similar issues. I opened her up and found quite a cake of dust around the processor heat sink and cooling fan. Vaccumed it all up and away she went.

Works fine now.

[Loose rivets]

Take battery out, power up on mains only, let us know what happens.


Oh my goodness, it's changed into a PC!! :}


Yep, blew it out in the garage today. Not too bad. Done reasonably regularly.

Memory now totally swapped with no benefit.

I'd typed about this amout when it crashed. So darn annoying, just can't read what's on the mass of data on the screen.

Is there anywhere that failure data is stored?

Could there be any link between the fault and starting without the power button being pressed? Still think coincidence, but I don't know.

EDIT I'd been running on Safe Mode for 40 mins or so. But I'd just started HDD Led. A smashing little Drive indicator I've used for years. Only other thing I did was to increase the screen res from 800 X 600 - I don't know if that makes a difference to the driver used while in Safe Mode.

[Milo Minderbinder]

I'd suggest you have a power regulation problem
Either the PSU is playing up, or the CPU voltage regulator capacitors on the motherboard are leaking / failing

[Loose rivets]

Looking at them, I'd take that seriously. Are the c's soldered right the way through? In the days of multi-layered boards, I don't dare guess what I'm going to find.

[Milo Minderbinder]

yes - the pins should go right through the board

You can usually see when wet caps start to go - the tops begin to bulge and often leak, with brown streaking. The boards are usually repairable if you have the skill and steady hand ( I don't...)

[Loose rivets]

Thanks for the suggestion. No biggie if I can't get it going, cos the lead I got for the Laptop will do 3.5" drives.


Well, the C's certainly need changing. The cross pressure splits are caked in brown goo and it would be easier to get data off the disc without messing with the USB lead.

Amazing, until you mentioned it, I was so used to seeing brown takky stuff on old C's that it looked natural. I grew up with Hunt's capaciters.:oh:

Once I've got the Rivetess on her way to the UK, I'll have a bash at that.

Discarded about a thousand old C's last trip home. Even the schools don't want electronics stuff now. Mind you, most of them were older than computing, let alone this computer.

Now all I've got to do is reconfigure the Foxconn PC that I used for NetFlix. Just don't watch telly anymore, so I've got this knocktogether.

Trouble is, it's going to take a day to get everything like home - assuming something else doesn't . . . oh, it has. Me anglepoise has gorn limp.

[Milo Minderbinder]

Probably fake Chinese capacitors

The story goes that a Chinese guy working in japan pinched the recipe for the capacitor powder, took it back to China where it got bootlegged and was used for making millions of fake caps
Only problem was the Japanese had guessed he was a problem and had fed him a fake recipe....
Its been a serious problem for quite some time. One reason to be very leery about ANY mission-ciritical electronics kit where you don't know the provenance of EVERY component

https://en.wikipedia.org/wiki/Capacitor_plague


edit
Wiki says Taiwan, not China and suggests its legit - but faulty - sources in Taiwan are the problem. This is at odds with "received wisdom" in the industry, which suggests its fake Chinese mainland parts which have flooded into the market which are the problem

[Loose rivets]

It always astonished me why Hunts capacitors lasted so long. If it had their name on it, we changed them faulty or not. Even if not faulty at the time, they soon would be.

I'll have a bash at the board when the dust settles from the Rivitess' departure.

[Milo Minderbinder]

If you can solder it shouldn't be too difficult

Word of warning though if it fails
Motherboards are cheap, assuming you can get one of the correct socket type
However HP, like Dell, try to make assembly cheap by using multi-pin connector blocks for the front panel leads. However the layout is often non-standard and you may need jumper leads to match them to a new motherboard. In the past I've been reduced to cutting the blocks down to individual leads with a scalpel....

Often the USB and front panel audio are non-standard layout as well

Only place I know to buy these is Maplin (in the UK) possibly someone like Farnell may have them in the USA

[Loose rivets]

Having a terrible time here with the 'new' computer. Had to format D drive to get rid of my beloved old WP 8. Would not save new files. Just can't change to Word mid edit.

It took FF with it, but fortunately there's not too much on the disc yet.

It may be I'll have a bash at the old HP sooner rather than later, but it doesn't owe me anything. Nice drive in it though. Barracuda. Transformed the machine. I may put it in as a secondary drive when I'm done. (ESDI.)

I'll start a new thread about drives shortly, as the WD one in the 'new' machine sounds like a drunk in a bucket factory and is noticeably slower than the Barracuda even though it's on a SATA interface. As I say, new thread for that one.

Solder? Hah! One thing I do know, I can't re-ball a :mad: Nvidia chip. Well, not after it's been glued to the MB. That was an HP fix I would guess.

[Loose rivets]

Well, thanks Milo for the suggestion about the caps. I wish I'd got them from the link above, but the ones I ordered were 10v as opposed to 6.3. Given the voltage across them is less, I'm hoping I haven't shot too high.


Fitting them was a :mad:tch! Really difficult to clean out the holes. Solder is not what it was and nothing seems to flow anymore. I had the iron up to 430.

Finally, I did what the guy said, and cheated. a .8 mm drill in one of those watchmaker's screwdrivers, has helped me many times. (just the shaft pulled out, and the bit glued in.) I only resorted to this when all other tricks had failed.

The swarf was very iffy, but finally they were drilled. This is when things got really tough.

The lack of flow - heat too low, or just the chemistry I don't know but it really looked like an idiot had done . . . oh . . .

Anyway, it's been on 'soak test' for 30 hours or so, and so far, so good. As the man said as he fell past the first floor.

[Milo Minderbinder]

How's it doing with the new caps after a month?

[Loose rivets]

Well, it ran for some time thanks, and then, wooed by the greater power of the one I'm using, I stopped testing it. Your post made me turn it on.

The fans made that noise they do when starting, a bit like the sigh of a satisfied woman, and then back to silence . . . a sound unlike any woman I know. It's sitting there with my favorite desktop picture, unencumbered by the clutter of Windows mechanisms.


I suppose I could have just said, Fine, and thanks for your help, but the sun is over the yardarm. ;)