HP TX2500 CPU woe

November 3, 2010 4:27 PM

My HP tx2500 recently conked out with a blink code 1 (replace CPU). I've replaced the CPU and reapplied thermal paste + copper penny shim to the GPU, to no avail. Could I do anything else before buying a new laptop?
posted by ntartifex to Computers & Internet (5 answers total)

Whether to try further depends on how much you are willing to spend to fix it. Possible problems at this point are that the replacement CPU is bad or you have a bad motherboard (two bad CPUs are less likely than one bad motherboard). Most likely, it's the motherboard. You could always try swapping a memory stick or power supply if you think one of them could be throwing the issues. Motherboards are going for $125 or so on Google Shopping.

Because you've already attempted work on it, HP would likely charge a minimum of $398+tax for a repair (assuming you are in the US, more in Canada) and possibly $698+tax to fix it. I didn't see any recall notices, but because you've attempted repairs the tablet won't be covered under a recall notice. The repair depots will notice the penny shim and thermal grease. HP repairs are $398 for one major, $698 for two majors; both the CPU and motherboard count as majors.

Credentials: have worked quite closely with HP's laptop repair centers in the past.
posted by Mister Fabulous at 5:45 PM on November 3, 2010

Best answer: The TX2500 series seems to be a bit prone to overheating.

After researching I have found a few reasons and possible solutions to this.


Problems:

The heatsink for the CPU is shared with the GPU, ergo, if one is overheating it may cause issues with the other.

HP has chosen a foam pad heat sink for the GPU, this makes overheating issues quite common in this line.


Solutions:

Ensure that the heatsink fan and heatsink unit itself are both completely free from dust and dirt.

Clean the processor and heat sink from old thermal compound using a suitable cleaning product.

Apply a SMALL amount of fresh compound to the processor and GPU and spread THINLY evenly.

Place the copper shim on the GPU and apply another small amount of thermal compound. This will ensure a good heat transfer from the GPU to the shim and then to the heatsink unit.


DO NOT UNDER ANY CIRCUMSTANCES USE A SHIM ON THE CPU. If you did this with the second CPU you may have blown it as well as the GPU on the mobo, as neither would have been transferring enough heat to the sink. A good thermal compound is all that is needed on the CPU (I like Artic Silver 5).

Using a copper shim is fine for the GPU as replacing the pad is advisable, however, using a penny for this purpose is not ideal as there MUST be a good contact between the GPU and heatsink and pennies do not have a completely flat surface. Buy a copper shim from eBay and some Arctic Silver 5.

Sorry to bear bad news but, there is a real chance that you now have two dud CPUs and a dud GPU on the mobo. Hopefully this is not the case.
posted by Don't_deceive_with_belief at 8:12 PM on November 8, 2010

Just a further note.

If the GPU on the mobo is the issue, there is a process called "reballing" which may help. Some specialists offer this service and kits are also available, although it is a meticulous process requiring a degree of skill and focus.

Hope some of this helps.
posted by Don't_deceive_with_belief at 9:24 AM on November 9, 2010

Response by poster: Hey all, a quick update on the situation. I attempted repairs as described (pretty much what Dont_deceive_with_belief said), to no avail. Reasoning that occasionally, throwing money at a new product is the best solution, I bought the tm2t with some seasonal discounts and cannibalized the old tx2500 for amusing parts.

While I mourn for my trusty old tx2500, the shiny is keeping me consoled.
posted by ntartifex at 10:48 AM on December 1, 2010

Response by poster: PS. As a happy aside, the tm2t fan does not attempt to roast my leg through convection.
posted by ntartifex at 10:49 AM on December 1, 2010