T60/T61 hybrid has no video output

[Zak]

I just constructed a pair of T60/T61 hybrids. The donor machines were a 14" standard T61p and a 15" T60p. The larger machine (T61 motherboard) works great. The smaller machine (T60 motherboard) doesn't output video either to the internal screen or to an external VGA monitor. Both machines were fully functional at the start of the project.

Are there any known issues with this combination that could cause a problem?

[Binh]

Unlike putting T61 mobo into T60 chassis, when you put T60 mobo into T61 chassis a care must be taken in order to make motherboard and bottom case to sit flush. Otherwise the LCD connector on the motherboard may be a bit lower than normal and you will have a poor contact between LCD cable and motherboard. This experience I got from making two T61 frankenpads (with T60p motherboard)

[Zak]

After additional attempts, Fn+F7 produced VGA output. I don't know why it didn't the first time.

It looks like that is, indeed the problem. The backing plate on the video connector is contacting the frame on the left side and doesn't appear to be fully seated. I've only seen information about the T60 frame needing modification to accept the T61 motherboard, not the other way around. Do I need to file a notch for the backing plate?

The GPU's thermal pad also seems to be barely making contact. It idles around 85C regardless of fan speed, and pressing on the HSF above the GPU results in a ~15C drop. Note: this is with Linux with the open source Radeon driver, which doesn't do any GPU power management by default. It is expected to run hot until I turn on power management. Would I be better off finding a chunk of copper to put in here, or a coin or something?

[Binh]

You need to file exactly two parts of structure frame as in the case T61 mobo into T60 chassis. No more.
Take a look from battery side, are the motherboard and bottom case sit flush to the structure frame?

[Zak]

Looking at it from that perspective, I can see clearly that it is not flush. I don't know how I missed that before. Thanks.

[TuuS]

regarding your heatsink, anytime you install one, not only when parts aren't designed to work together, but even a stock replacement, always make sure you have a proper fit. The gpu platfor often will be mis-aligned. I like to use a small strip of paper and slide it between the platform and die, then using light pressure on the platform it should grip the paper equally on any part of the die, if it grabs easier on one side, that usually means your hsf needs adjustment. When building a frankNpad this is even more important since the chip height may be different then the board that the heatsink was designed for.

Most important is taking your time and making sure everything fits perfect and you should be fine.

[Zak]

Thanks for the input. I should have checked the alignment more carefully when I reassembled. I expect the alignment to be a lot better once I file down the appropriate sections of the T61 frame.

I kept the HSF assemblies with their original motherboards. The T60 HSF has a thick thermal pad for the GPU while the T61 does not, so I figured it would be best to keep them together. I later read that the T61 HSF cools better, which is preferable as the laptop with the T61 motherboard (is there a naming convention for these hybrids?) will be subjected to heavy load more often.

[RealBlackStuff]

(is there a naming convention for these hybrids?)

FrankenPad, some spell it FrankNpad.

[Zak]

Yes, I got that part. I was asking for a way to name the specific laptops, as I have two here - for example, using the donor motherboard first (making the higher-spec unit a T61/T60).