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I won a local auction for an Apple Lisa!!!

Started by berskyboy, August 22, 2026, 11:21:06 AM

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berskyboy

#120
Yesterday at 12:04:22 PM
Quote from: sigma7 on Yesterday at 05:20:40 AMExcellent; to see how it behaves compared to the other one, try these measurements again using the diode test mode:


Diodes   Fwd, Rev            Description       Measurement
{BA, BB}   0.13, inf   CR20a, CR20b      BA: 0, OL BB: 0,OL
{DA, DB}   0.30, 0.37   CR25, CR23        DA: OL,OL DB:
.
I stopped because should I put Q1 and Q2 back into the PSU?

And for each of Q1 and Q2 now out of circuit, also measure

Q1
Red to Black         
Lead 1 to Lead 2.       0       
Lead 2 to Lead 1        0.1

Q2
Red to Black         
Lead 1 to Lead 2        0.8
Lead 2 to Lead 1        0.6

sigma7

#121
Yesterday at 01:33:42 PM Last Edit: Yesterday at 01:43:14 PM by sigma7
Quote from: berskyboy on Yesterday at 12:04:22 PM
Quote from: sigma7 on Yesterday at 05:20:40 AMExcellent; to see how it behaves compared to the other one, try these measurements again using the diode test mode:

I stopped because should I put Q1 and Q2 back into the PSU?

No, make these measurements with Q1 and Q2 removed, but that is a good question.

QuoteDiodes  Fwd, Rev            Description      Measurement
{BA, BB}  0.13, inf  CR20a, CR20b      BA: 0, OL BB: 0,OL
{DA, DB}  0.30, 0.37  CR25, CR23        DA: OL,OL DB:

And for each of Q1 and Q2 now out of circuit, also measure
Q1
Red to Black         
Lead 1 to Lead 2.      0       
Lead 2 to Lead 1        0.1

Q2
Red to Black         
Lead 1 to Lead 2        0.8
Lead 2 to Lead 1        0.6

Are those measurements using a "diode test" function? From the readings I'd guess it was a resistance mode.

So I can peruse the manual, what is the brand and model of DMM you are using now?
Warning: Memory errors found. ECC non-functional. Verify comments if accuracy is important to you.

berskyboy

#122
Yesterday at 02:52:45 PM
Quote from: sigma7 on Yesterday at 01:33:42 PMAre those measurements using a "diode test" function? From the readings I'd guess it was a resistance mode.

So I can peruse the manual, what is the brand and model of DMM you are using now?

Here's a photo of it. ASTrOAI CM2KOR
https://www.dropbox.com/scl/fi/2giwzufwhe0l051stcxix/ASTrOAI.HEIC?rlkey=b7got1wh776cwtdchmoxarybb&st=i8ld7461&dl=0

that was in diode mode.

sigma7

#123
Yesterday at 02:57:02 PM Last Edit: Yesterday at 03:03:12 PM by sigma7
Quote from: berskyboy on Yesterday at 02:52:45 PMHere's a photo of it. ASTrOAI CM2KOR
https://www.dropbox.com/scl/fi/2giwzufwhe0l051stcxix/ASTrOAI.HEIC?rlkey=b7got1wh776cwtdchmoxarybb&st=i8ld7461&dl=0

that was in diode mode.

Test CR18 on the component side (one end still disconnected from the board) in both directions using the diode test mode.

Note the manual says on page 17 that to enter Diode Test mode, you have to press the "Func" button after rotating the switch to the diode test/continuity position. When in that mode, the diode symbol will be shown in the display.
Warning: Memory errors found. ECC non-functional. Verify comments if accuracy is important to you.

berskyboy

#124
Yesterday at 03:04:53 PM
Quote from: sigma7 on Yesterday at 02:57:02 PMTest CR18 on the component side (one end still disconnected from the board) in both directions using the diode test mode.

CR18 in diode mode
OL, OL

CR18 in resistance ohm mode
33.4, 0.45

sigma7

#125
Yesterday at 03:07:04 PM
Quote from: berskyboy on Yesterday at 03:04:53 PM
Quote from: sigma7 on Yesterday at 02:57:02 PMTest CR18 on the component side (one end still disconnected from the board) in both directions using the diode test mode.

CR18 in diode mode
OL, OL

Did you see the edit I made that says "Note the manual says on page 17 that to enter Diode Test mode, you have to press the "Func" button after rotating the switch to the diode test/continuity position. When in that mode, the diode symbol will be shown in the display."?

If not, try the test again in diode test mode.
Warning: Memory errors found. ECC non-functional. Verify comments if accuracy is important to you.

berskyboy

#126
Yesterday at 03:11:55 PM
thank you for that

CR18 in diode mode
0.462V, OL

sigma7

#127
Yesterday at 03:14:23 PM
Quote from: berskyboy on Yesterday at 03:11:55 PMthank you for that

My pleasure.

Test Q1 and Q2 again, out of circuit, use the diode test and check all 6 permutations:

Red to Black
Lead 1 to Lead 2
Lead 2 to Lead 1
Lead 1 to case
case to Lead 1
Lead 2 to case
case to Lead 2
Warning: Memory errors found. ECC non-functional. Verify comments if accuracy is important to you.

berskyboy

#128
Yesterday at 03:27:49 PM
Quote from: sigma7 on Yesterday at 05:20:40 AM
DiodesFwd, Rev        Description
{BA, BB}0.13, infCR20a, CR20b
{DA, DB}0.30, 0.37CR25, CR23
.
TransistorsRed-BlkDescription
{1-2, 4-5}1.25Q4, Q3 c-b
{2-1, 5-4}0.62Q4, Q3 b-c
{1-3, 4-6}0.70Q4, Q3 c-e
{3-1, 6-4}1.89Q4, Q3 e-c
{2-3. 5-6}0.64Q4, Q3 b-e
{3-2, 6-5}infQ4, Q3 e-b

And for each of Q1 and Q2 now out of circuit, also measure

Red to Black
Lead 1 to Lead 2
Lead 2 to Lead 1


Now my new measurements:


Diodes  Fwd, Rev            Description      My Measurement
{BA, BB}  0.13, inf  CR20a, CR20b      BA: 0.126, climbing BB: 0.126,climbinng
{DA, DB}  0.30, 0.37  CR25, CR23        DA: 0.26, 0.277 DB: 0.267, 0.260

Transistors    Red-Blk    Description. My Measurement:
{1-2, 4-5}    1.25    Q4, Q3 c-b.  0.775, 0.767
{2-1, 5-4}    0.62    Q4, Q3 b-c.  0.572, 0.566
{1-3, 4-6}    0.70    Q4, Q3 c-e.  0.661, 0.681
{3-1, 6-4}    1.89    Q4, Q3 e-c.  1.583, 1.585
{2-3. 5-6}    0.64    Q4, Q3 b-e.  0.612, 0.618
{3-2, 6-5}    inf    Q4, Q3 e-b.  1.712, 1.725

Q1
Red to Black       
Lead 1 to Lead 2.    0v       
Lead 2 to Lead 1      OL

Q2
Red to Black       
Lead 1 to Lead 2      0v
Lead 2 to Lead 1      0v

berskyboy

#129
Yesterday at 03:31:55 PM
Quote from: sigma7 on Yesterday at 03:14:23 PMTest Q1 and Q2 again, out of circuit, use the diode test and check all 6 permutations:

Red to Black
Lead 1 to Lead 2
Lead 2 to Lead 1
Lead 1 to case
case to Lead 1
Lead 2 to case
case to Lead 2

Q1
Red to Black
Lead 1 to Lead 2 0v
Lead 2 to Lead 1 OL
Lead 1 to case 0v
case to Lead 1 0v
Lead 2 to case 0v
case to Lead 2 0v

Q2
Red to Black
Lead 1 to Lead 2 0v
Lead 2 to Lead 1. 0v
Lead 1 to case 0v
case to Lead 1 0v
Lead 2 to case 0v
case to Lead 2 0v

sigma7

#130
Yesterday at 04:18:45 PM
Quote from: berskyboy on Yesterday at 03:31:55 PM
Quote from: sigma7 on Yesterday at 03:14:23 PMTest Q1 and Q2 again, out of circuit, use the diode test:
Q1
Red to Black
Lead 1 to Lead 2 0v
Lead 2 to Lead 1 OL

Check this again, if it is a short circuit, it should be bidirectional.

With Q1 and Q2 and CR18 still out of circuit, do these again using the diode test (we are looking for additional problems):

Diodes    Fwd, Rev    Description
{AA, AB}0.46, infCR18, CR19
{BA, BB}0.13, infCR20a, CR20b
{CA, CB, CC, CD}0.5, infCR1, CR2, CR3, CR4
{DA, DB}0.30, 0.37CR25, CR23
{EA, EB}0.38, infCR26, CR24
{FA, FB}0.41, infCR22, CR21
.
Transistors
Red-BlkDescription
{1-2, 4-5}1.25Q4, Q3 c-b
{2-1, 5-4}0.62Q4, Q3 b-c
{1-3, 4-6}0.70Q4, Q3 c-e
{3-1, 6-4}1.89Q4, Q3 e-c
{2-3. 5-6}0.64Q4, Q3 b-e
{3-2, 6-5}infQ4, Q3 e-b
Warning: Memory errors found. ECC non-functional. Verify comments if accuracy is important to you.

sigma7

#131
Yesterday at 04:20:34 PM
Oh maybe you just did that... wait while I review
Warning: Memory errors found. ECC non-functional. Verify comments if accuracy is important to you.

sigma7

#132
Yesterday at 04:27:33 PM
Quote from: sigma7 on Yesterday at 04:20:34 PMOh maybe you just did that... wait while I review

Most looks good.

Quote from: berskyboy on Yesterday at 03:31:55 PM
Quote from: sigma7 on Yesterday at 03:14:23 PMTest Q1 and Q2 again, out of circuit, use the diode test:
Q1
Red to Black
Lead 1 to Lead 2 0v
Lead 2 to Lead 1 OL

Check this again, if it is a short circuit, it should be bidirectional.

With Q1 and Q2 and CR18 still out of circuit, do these again using the diode test (we are looking for additional problems):

Diodes    Fwd, Rev    Description
{AA, AB}0.46, infCR18, CR19
{CA, CB, CC, CD}0.5, infCR1, CR2, CR3, CR4
{EA, EB}0.38, infCR26, CR24
{FA, FB}0.41, infCR22, CR21
.
Check the following again with the daughterboard removed:
Transistors
Red-BlkDescription
{3-2, 6-5}infQ4, Q3 e-b
Warning: Memory errors found. ECC non-functional. Verify comments if accuracy is important to you.
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