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General discussion

Overheating, Shutting Off, Re-wireing???

Nov 23, 2004 5:45AM PST

I have a Compaq Presario 1235 Laptop that has been in and out of 3 shops over a 2 year period and I am about to part it out unless I can get some help on the Forum. Im in Mexico and the first shop thought it was a memory problem but couldnt fix it. The second shop said it was the hard drive but after replacing the hard drive it had the same problem. The third shop with an American tech has put several hours into it and says that the fan is not cooling the systen suffiecntly and it shuts down after a few minutes when it gets hot. He says he can fix it If he could figure out another way to wire the fan? So I am assuming that something on the motherboard is burnt out and he needs another access point to rewire or direct current to the fan. If any one has any idea on what can be done I would appreciate it. Although it is an older laptop it probably only has a 100 hrs of use. Thanks, Dan diverdan007@yahoo.com

Discussion is locked

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What's the issue?
Nov 23, 2004 5:59AM PST

"it shuts down after a few minutes when it gets hot."

Does it shut down withing a few minutes of getting hot?

-or-

Does it shut down within a few minutes?

Here's a thought. Boot a DOS diskette. Does it run longer?

Why the thought? I'm finding pests, spyware, bad software, more that run the CPU at full tilt and some laptops can not do that. Booting to DOS is a test I use to see if something it running the CPU at full tilt.

Yes I have more ideas, but your post was light on the details of OS and more.

Bob

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As always Thanks Bob...
Nov 23, 2004 10:06AM PST

Ill check with the Tech and try to get more details. Thanks again-Dan

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Re: As always Thanks Bob...
Nov 23, 2004 11:17AM PST

Well heat could certainly be an issue. Manufacturers design these computers with everything they need in the way of power and cooling. So I can't imagine that the fan would be insufficient to cool the computer unless, as you say, something is burnt out.

My gut is to say that the power supply is too low on wattage. But in a lapop it runs on batteries so it doesn't have to have a power supply. But it could be that the power delivery system is bad, or the battery is going bad.

That's something. You say it's old but hasn't had much use. Well how old is old? The battery could simply be bad.

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possible...
Jan 26, 2005 12:17PM PST

Diverdan

I hope you are still looking for answers, because I may have a few for you... First off, yes, it could be overheating. I recently decided to completely mod out my 1235 and it has become quite the project. First off, let me mention that I never had a heat problem when I was running win98, however I notice that xp seems to run warmer. I upgraded the processor so mine handles xp better, but I would imagine that if you installed xp the temp would rise. Secondly, the fan is really only a fixture that serves very little purpose in the original state. I have experimented with mine and noticed no correlation between the temperature and when the fan turns on. In fact my system used to freeze up because it was so hot, and the fan never kicked on. Last, the heat dissipation from the k6 that you have installed is hindered by design. First the amd design has a 1mm aluminum plate over the dye with a thermal adhesive holding it on... second the presario 1235 is cooled by a solid block of aluminum with a thermal pad on it which is screwed to an aluminum plate which spans across the bottom of your keyboard. The thermal pad which sits on the processor is extreemly ineffecient, and the block serves to spread the heat.
Your fan runs on a 5v power supply. the nearest 5v power supply is the usb just to the side of it. Be warned that the connections are very small and heat can damage them easily... (I know, I did and had to install a voltage regulator to fix it) So solder with care. If you still have the original k6-2 266 processor, running the fan constantly should help enough to keep your system stable. If you upgraded to a newer OS you may want to go back to win 98 (at least to see if it helps).
This website should give you the info you need on the usb wiring.
be warned! to do this is to have yourself, or the tech completely disassemble the laptop as the usb connections are on the bottom of the MB!

http://www.usbman.com/Guides/BelkinMotherboard_cable_assembly.htm

also, this is the only semi-detailed manual for the 1235 that I have been able to find.

http://h18027.www1.hp.com/athome/support/msgs/1230-50/

I hope this helps and if you would like to see the mods I did or just the wiring into the usb (which I did mess up I will admit) email me at cubadew@yahoo.com. I think you will find the mods interesting as I completely rebuilt the system to have an active cooling system with an additional 2 more fans and two custom built heatsinks connected by a heatpipe cooling my 400mhz k6-III+ processor.

good luck

cubadew

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Second fan socket
Jan 27, 2005 8:51PM PST

There is a second fan socket on the right side of the board thats not used on this model. Extend the fan wires and plug it in here and it will run full tilt while the machine is on. you could also wire this through a thermistor to run the fan acording to ambient temp of the CPU. Passive cooling for most laptop CPU's is 85C so you'd want a cooler or lower temp therm to glue to the top of the CPU (off to the side of the heatsink) Around 100 degrees F would keep it cool.. Run Memtest 86 from boot..(Google,download, install on floppy).. This will tell if the onboard 32 megs is having faults. If it does these have been known to be nothing more than a bad solder joint.. Good luck!

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where?
Jan 27, 2005 9:40PM PST

I dont mean to seem critical... but where is this connection? I just went and looked because I never noticed it and it would have solved a ton of wiring issues that I had to delegate to a voltage regulator. I have a couple pics of a presario 1235 MB if you want to look at them.
Seriously, if you think there is a second connection I really do want to know where it is. Is it unused and therefore has no plastic base, or is just marked as a connection but is really only 2 solder points? If it exists, I could really use it in the mod Im working on.

if you want to look at the pics just drop me a line, I really am interested in this second socket.

thanks
Cubadew

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Incorrect model apologize
Jan 29, 2005 7:14AM PST

My mistake I was looking at a 12XL board these do have a second unused fan socket directly off the power supply that carry a 5V constant supply. Ive used these before to run a fan on oldr mod jobs much like you are doing now.. You emailed and Yes I'd like to see the pics of your creation.. Always like looking at the ingenuity of others!