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Home Forums 68kMLA 'Non-working' M0001A — #3
Post #3 by equill
Source Forum68kMLA
CategoryHardware
Post DateThu, 12 Jun 2008 - 10:36
Original URLhttps://68kmla.org/bb/threads/non-working-m0001a.13489/
Post
The Plus arrived today. I have to guess that it is a platinum Plus, by its colour (very little yellowed) and serial number. Its particulars are:

Macintosh Plus 1MB

Serial (on the case bottom rather than beside the brightness control): E9133BUM5880X, ie, 13th week of 1989

Bezel: 810-0379-A

Keyboard: M908M0110A0830, ie, contemporary with the Plus, and the correct model

Mouse: M906M010097103, ie, also contemporary, and the correct model

MLB: 820-0174-D (1986-87), 630-4122-A

Power/sweep board: 630-0108 International 240VAC

ROM: 342-0341 HI, 342-0342 LO (1986-87)

RAM: 2 x 256kB 120ns (Apple-branded, with TI chips), 2 x 1MB 70ns (Dated 1992, Mitsubishi chips). R8 had been clipped, correctly. R9 was never present.

CRT: Clinton 825-4002-A

FBT: Lifon E94167

Oscillator: Fox 15.667200MHz

Battery: an original Eveready 523, showing 0.14V

The Mac has only minor yellowing, on (presumably) the side exposed to natural light. Inside there was a thin film of dust on the top surface of the CRT and floppy drive. For the rest, it might have come out of the factory only this year. There were no gouges along the case seams, and the RFI shield was present and shiny clean, with only the prints, of whomever made the RAM upgrade, on it.

I replaced all the RAM with four identical 8-chip 1MB SIMMs containing Mitsubishi 80ns chips, and removed and reseated the ROM chips. No capacitor leakage or swelling was to be seen.

It had been sold as 'not working' perhaps because of its behaviour at startup: chime, raster, Sad Mac with 0300FF in a mixed black and grey screenful of short, thick vertical bars. It is the first time in my life that I have seen a hardware error (bad byte-write in memory test) accompany Sad Mac in a Macintosh.

The Plus came with Mac Plus Owner's Guide, SE/30 Owner's Guide, Rodime 20 Plus external HDD (in a style like that of the Apple HD20), Rodime Software User's Guide, and Setting Up Your Macintosh Plus.

Pics when I make the time to take them, and I mean make the time. There isn't any just lying about.

de

mp.ls