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M/75 Dead, My Explorations in Board Level Repairs, P/75 as main?

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So last night I was playing Hoyle Soliatire on my NEC Versa M/75 and of course somewhere along the lines I had to move, screen shifted, and then the computer shutdown and would not come back up, acting fully dead. So I guess it's time to do some board-level 486 autopsy. Kind of a shame, that was my favorite one, but I guess the P/75 has not been getting enough "love" lately so I'll tune that one and tweak that one, plus give it a chance to be a FreeDOS beast, and maybe also bring the 40EC back into action as well.

That said, I've really been batting 100% on these electronics repairs lately, at home, at work, in the far I've fixed the headlamps in my truck, a CRT Television is well on it's way to being fixed (a very very nice Mitsubishi from 1989), and my NEC laptops do need some TLC in that area as well.

The P/75 needs the least, CMOS battery issues. Probably should just get a 2450 battery holder off E-bay and call it good. It's had trouble storing settings the whole time I've had it, and right now it's using a CR2302, I just don't think it has enough juice for that.

The M/75 is going to need power circuit autopsy. Likely a component got burned, shorted, or broken. I'm a bit rough on SMD's when I work on them but maybe I can get it. If I can't figure it out it becomes a parts unit and the P/75 will take over as the main (looks like it'll be time for me to restore the other two batteries then - that Pentium PRocessor EATS batteries).

The 40EC does have some power demons of it's own. I did some diagnostics earlier this year and the original power board was bad, again, probably short or break in the circuit somewhere via bad component or some kind of failure - however, I have a glimmer of hope in that there is a SMD fuse on that board so I can fix the original board. Turns out the original motherboard is just fine (!!) - so I have a spare, so that's nice. It's running fine as/is but the battery circuit seems a little, uh, cranky and just pretends the battery is full all the time. The screen is also washed out (it's actually the M/75's original screen), so I might put the original screen back in if I Can't get the M/75 working again.

I'm seriously tempted to pick up a FOURTH one off e-bay, just because I have so much invested in this laptop range and I have special skills now at getting these NEC Versas to run like monsters. There's a 50EC on there right now for $34.99, I'm going to stalk it till it gets cheap, then do all the same stuff I did to my 40EC to it if I decide to get it as it's the same hinge issue they always have. Then slap in a Seagate Momentous 80GB drive like the others.

The P/75 might make a better main though the more I think of it. The audio is SoundBlaster compatible, it can record digital audio, the 800x600 pixel screen is better for web surfing and the hinge and overall structure seems a lot stronger than the 486 Versas - odd since it's the same design. The battery life may be shorter, but I don't really use the batteries that much anyway, plus the performance mirrors the M/75 pretty much.

So we'll see where this goes. I'm tempted to maybe make the M/75 the Windows 95 laptop once fixed as it uses WSS, either that or DOS 7.1 with a modified WFW311 setup on it, because the P/75 has things more like I want them for a FreeDOS system.

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