1987 Macintosh Plus (Platinum)

Kai Robinson

TinkerDifferent Board President 2023
Staff member
Founder
Sep 2, 2021
1,153
1
1,162
113
42
Worthing, UK
1 to 3 = 1.5Meg
2 to 4 = 1.5Meg
5 to 7 = 1.5Meg
5 to 8 = 1.5Meg

All measured in circuit :/
 

RetroTheory

Tinkerer
Oct 17, 2021
77
118
33
That makes no sense to me, even if it's the wrong coil they should not be the same. I can send you a tested flyback if you want
 

RetroTheory

Tinkerer
Oct 17, 2021
77
118
33
Damn, unless they are rectified coil output , have you tried a diode test across the pins either way, it's the wrong coil anyway but might explain why you are not getting continuity and may explain the cap popping
 

Kai Robinson

TinkerDifferent Board President 2023
Staff member
Founder
Sep 2, 2021
1,153
1
1,162
113
42
Worthing, UK
Did a bit more measuring:

between pins:

1 + 4 = 1.5 ohm

1 + 5 = 1.5 ohm

2 + 3 = short

2 + 7 = short

2 + 8 = short

3 + 7 = short

3 + 8 = short

4 + 5 = short
 

RetroTheory

Tinkerer
Oct 17, 2021
77
118
33
Better and much worse, there should be no connection at all between 1 and 5 for a start . Not to mention the rest .
 

Kai Robinson

TinkerDifferent Board President 2023
Staff member
Founder
Sep 2, 2021
1,153
1
1,162
113
42
Worthing, UK
@techknight dug this up in the discord:

Screenshot 2022-05-23 234932.jpg
 

Stephen

BetterBit
Staff member
Founder
Sep 5, 2021
200
245
43
San Francisco
From two known-good analog boards (in-situ):

IMG_3039.jpg
"TAI-HO TH1565" flyback on a 630-0102 Analog Board

  • 1 to 3 = 0.4 Ω
  • 2 to 4 = 0.8 Ω
  • 5 to 7 = 4.3 Ω
  • 5 to 8 = 1.4 Ω

  • 1 + 4 = .9 Ω
  • 1 + 5 = O.L.
  • 2 + 3 = .7 Ω
  • 2 + 7 = 17.56K Ω
  • 2 + 8 = 4M Ω (some fluctuation)
  • 3 + 7 = 93K Ω (some fluctuation)
  • 3 + 8 = 3.5M Ω (some fluctuation)
  • 4 + 5 = 3.5M Ω (some fluctuation)

IMG_3040.jpg

Unmarked flyback on a 630-0102 Analog Board
  • 1 to 3 = 0.7 Ω
  • 2 to 4 = 0.8 Ω
  • 5 to 7 = 4.2 Ω
  • 5 to 8 = 1.5 Ω

  • 1 + 4 = 0.8 Ω
  • 1 + 5 = 3.5K Ω (some fluctuation)
  • 2 + 3 = 0.8 Ω
  • 2 + 7 = 20M Ω (some fluctuation)
  • 2 + 8 = 10M Ω (some fluctuation)
  • 3 + 7 = 3.5K Ω (some fluctuation)
  • 3 + 8 = 3.5K Ω (some fluctuation)
  • 4 + 5 = 3.5K Ω (some fluctuation)