All,

I have a Compaq H3975. I inadvertently plugged a 9 or 12 volt dc power supply into it and "took it out". Nothing works now.

Any suggestions on what I need to repair?

I have a new replacement battery coming, but wondered if there is a internal fuse that must have blown.

tnx

Cowboy47

it might of fried the whole motherboard or at least the power supply
I did this to an old dell (plugged my pda plug into it) and it smoked

My friend and I both did a nice job toasting our first builds due to a rather unsafe power situation a year or two back.

Two of the power couplings from his PSU were burnt beyond what I thought possible.

My observation:
I find the PSU goes first: It has to manage to power, after all, and will either cope with the unsafe power as it passes through, directly affecting your components, or the PSU will die immediately and hopefully the power doesn't get to the rest of the machine. Replace this device immediately, it's very likely the cause (preferably with an ANTEC, very stable and potent stuff... even if it's one of their lower-end models).

After the PSU, the motherboard, a rather sensitive piece of hardware, is most likely to fry. Good idea to replace the battery, like you mentioned. Then, proceeding in likelihood to die; the processor, your video card (especially if it requires a 4-pin or two to power up... dunno if HP's come with PCI Express cards...), then all the other peripherals in no particular order, since I haven't had a problem with power and RAM or hard drives yet.

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