I don't have a 200 schematic, but someone suggested putting the cap a diode drop below the rail. Worth a try, IMHO.
FWIW, my 2 NEC 8201a Supercap transplants (2011) continue to behave themselves. For anyone tempted, last time I looked there were 5 F / 5.5 VDC supercaps out there... On 9/14/17, Kurt McCullum <[email protected]> wrote: > I had replaced the batteries in both my 102 and NEC 8201 with the > capacitors. The NEC was just starting to corrode at the ends of the battery. > I was thankful I caught it before it moved down to the PCB. The 102 didn’t > really need to be done but I ordered 5 capacitors so I went ahead and did > it. I had my 200 open because the AC adapter port was loose. It would wiggle > up and down and only work part of the time. A simple re-solder solved that > and I decided to swap out the battery with a capacitor while I was in there. > But the 200 power circuit didn’t like the voltage of the capacitor so I just > removed it and run it without backup. I run it 95% of the time off of AC and > if I need to swap batteries without losing the contents I just keep the AC > adapter plugged in and put in fresh batteries. > > > > From: M100 [mailto:[email protected]] On Behalf Of Rick > Sent: Thursday, September 14, 2017 9:14 AM > To: [email protected] > Subject: Re: [M100] model 200 won't power off > > > > Kurt, what led you down the path of needing/wanting to change out the > battery? > > I haven't cracked this one open yet so I have no idea what the physical > condition of the battery is. It did readily charge up though with no > fussing. I would think after all this time I would have too little voltage > going on here versus too much. (Assuming a previous owner hasn't fiddled > with it yet.) > > Rick > > _____ > > My 200 didn’t want to power down when I swapped the battery for a super > capacitor. Too much voltage so it never shut off. Just two lines across the > screen. I ended up removing the super capacitor and now run it without a > backup battery. That solved my problems. The power circuit is very sensitive > to voltage. > > > > Kurt > > > > > >
