Schematics for HP/Compak NX9110 Notebook Main Board

You'll never find one; these devices are not serviceable at the component level and all accessible documentation will, at best, give you only a subassembly-level guide.

In many cases, if you have standby voltage present on the board and it won't fully power up for some reason, the signals in question will trace back to a slave micro that manages power and other misc. functions. It's usually an 8-bit micro. In modern machines this is often an all-in-one chip containing the keyboard and pointing device interface also. Often the "no switch on" decision is being made internally to that slave micro based on other inputs, the state of which you have to infer.

I'd try hotwiring the regulator "on" and see what happens - given that the board is garbage already. However I've rarely been successful at fixing component-level problems on laptop mainboards; without design intent information, everything has to be analyzed from first principles.

Schematics don't exist outside of the development engineering organization. Even the service manuals don't have them.

Alf Katz wrote:

A company named SAMS used to reverse engineer electronic devices and then make a schematic for it as well. I recall they did this for many computers back in the 80's. I don't know if they are still around. As they went back for decades for TVs and radios. I should still have my SAMS schematics for my Commodore VIC-20. I have my Commodore SX-64 (first color luggable) schematics straight from Commodore themselves. Ah... things isn't like this anymore, eh?

Technology to do this has become much easier. There's software now that will take as input standard X-rays of a PCB and create a netlist from that more or less automatically.

The reason it's not done commercially any more is because the information is useless. 99% of the time even if you can work out which part is actually faulty, this merely leads you to "Replace ASIC that isn't available off the shelf". And the debugging time, at $85 per hour or more, rapidly approaches the $500 cost of a new machine.

Hello Bill Do you have by any chance a circuit diagram for the English made Commodore C64. I have 3 faulty C64 and one complete working and one without sound. Want to tackle them sometime in the future. Greetings Bert

You are talking about "Sams Photofacts", and they were not reverse engineered, they were based on information voluntarily supplied by manufacturers. They were the source of information used by repair shops for TVs, radios, stereos and car radios. They did some computers and some monitors back in the 1980's.

They've been around since 1946 and are still in business:

But you won't find schematics of laptops, in fact I don't think you will generally find computers at all.

snipped-for-privacy@gmail.com wrote:

Really? Sams Photofacts claims reversed engineering like I said.

I have the service manual for a Commodore SX-64 in storage, which is electronically the same. But 8-bit computers like the Commodores are easy to repair even without a schematic. See:

No sound is usually the SID chip, 6581

Yeah I know, isn't that something? I started having trouble when things came out with muli-layer boards. I guess it is called progress! :(

Still being done ... see the experts...

"APR" >

Hahahaha... I have some Roswell control panels I need to have reversed engineered. They sound perfect. Thanks again! :D

Not quite. No sound is often the power supply. The only things on the C64 board that require the 9VAC are the audio and a passthrough to the user port. Not all flavors of the C64 PSU put out 9VAC, so mixing and matching the PSUs can lead to no sound.

Oh okay, I stand corrected! Thanks zwsdotcom ;)

notebooks,

Commodore released manuals with schematics for their 8088 and 80286 IBM clones. I had originals of each, about 10 years ago.

notebooks,

I don't know why I didn't think of this before, as I have used the FCC website before. But supposedly anything with a FCC number, had to file a schematic with the registration. I never thought about computers, but I have gotten schematics for other devices before. Might be worth a shot.

The second one takes you to the search page, I hope.

No longer true, one need only file a block diagram describing process flow and voltages. MB schematics for computers have been deemed proprietary.

Not strictly true. The full information is still in the filing. Certain information can be kept off the public record as a trade secret (exactly what you can get classified this way depends on how well your lawyer can dance).