[NTLK] MessagePad 100 (OMP H1000) Flickering/glitching
Erik Johnson
apple.newton at retro.network
Sun Oct 7 03:42:22 EDT 2018
Oh good my message made it!
> Wow. How cool! This is the type of information that usually makes my
> day. Or, to be more precise, the days in at least the coming two
> weeks :-)
...
> If replacing C51 will always fix this problem, you can proudly say
> that you've done a lot towards keeping the Newton platform alive and
> kicking. And you'll have saved not only your Newton, but many others
> all over the world, starting with the three that are currently within
> my reach.
Please let me know how it goes! I'm still not sure why after all my
searching I found no mention of these by anyone except a vague
"probably" reference to "capacitors" on 68kmla. I have a dead MP110 on
its way too, but it has known battery damage. I'll see about that...
> C51, by the way, is part of the LCD boosting circuit. The power to
> operate the LCD is generated by a step-type chopper-system converter
> around IC 18. In a nutshell, this converter generates 28 Volt from
> the battery voltage. C51 is at the end of it. It is supposed to
> stabilize the LCD supply voltage. I'd assume that the display would
> behave exactly the way you described if this voltage isn't steady.
I figured it was part of some booster because of the mechanical ticking
noise it was making, much like an inductor being pounded. And its
proximity to a beefy inductor under there :)
- Erik
More information about the NewtonTalk
mailing list