280c Duo KBD troubleshooting INSANITYYYYYYY . . .

[Trash80toHP_Mini]

I got the sucker! I've just gott share this one . . .

jruschme sent me the last of his formidable Duo & Duo accessory collection . . . thanks again, JR! :approve:

. . . and a little problem that came close to knocking me off my mental hobby-horse!

BTW... I'm just curious. Were you able to figure out why I was having trouble with the keyboard on the 280c?

I've got Duos and Duo Guts scattered hither thither and yon ATM. Four are fully assembled, your 280c almost fully assembled, one very partially completed FrankenDuo2300cTB and a bunch of others in parts boxes, in parts and only the great pumpkin knows what else in the rest of the unlabeled boxen as well as PowerDuo, my original 2300c hopefully ensconced in its plastic drawer/box right below the PaladinKBD/TrackBallProtoInputCombo, but there are too many baskets of laundry and MacParts . . .

< climbs over to check . . . nope . . . checks . . . phew! >

. . . PowerDuo is one of the fully assembled ones, along with your 270c, my 250, and an unitentified one with a Color Lid and Clean Top Deck, so it's likely a 2300cTB I've forgotten about! :lol:

. . . got one bong the first time around on that one, no video, and then nada! That one goes on the bench next!

280c KBD degugging results:

editing end of favorite graphics/word processor polishing yielded a no go . . .

random loose KBD candidate #1, contacts erased, no go . . .

random loose KBD candidate #2, contacts erased, no go . . .

Interesting Observations:

the Power Key on the modem doesn't bring up the shutdown dialog box, while the IIgs ADB KBD does . . .

the Shutdown Button on the back works . . .

got an unexpected boot chime after shutdown when I shoved unit back against said KBD, no video output . . .

needed to hit the shutdown key on back and got abbreviated death chimes as I pushed it . . .

Next Step:

replace modem with power board . . .

Preliminary WAG:

partially whack Power Manager IC

The jury is still out, but I'd put money on that WAG . . .

jt

I'd have lost that bet . . . sorta . . .

I discovered the unmarked top plate "PowerDuoTB" was the dead screen 280c I bought with a bunch of other stuff from a member, tried that MoBo . . . no-go . . .

I tried EVERYTHING Last night and this morning, when I wound up with a 280c2300cTB that exhibited the same symptoms with the three different keyboards . . .

8-o the ONLY thing that hadn't changed was the perfectly functioning LCD . . .

Would you believe the problem was in the LCD!!!!!! :?:

snagged a MiniDock, hijacked the Sony 17" test bench MultiScan CRT, unhooked the LCD connector and . . .

:O all was good, the Power Button was even fully functional along eith KBD #2! However, this Cherry (semi-borked) LCD has no place being in a Duo . . . so it'll go into a, yet to be sourced, Classic Shell where it's nefarious KBD/Power Button borkification habits won't bother the 2300c MoBo one little bit!

I've already done a dry run of de-Goitering on a DOA 2300c LCD, so I've disproved the commonly accepted wisdom that a Duo LCD won't fit into a Compact . . .

. . . and there'll be my DeadROM Dock+ board in there with a pair of NuBus Cards too! }

Whew! Now I can relax, shower and head off to work in a much calmer state of mind! :approve: