(for testing Macintosh® LC, LC II, Classic II computers)
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CONTENTS:
1. NEW FEATURE: "TstMd via ADB"
2. Parameter RAM Problems
3. ERRATA for CPU Tests, Vol. 2, Troubleshooting Guide
4. Performa™ 200, 400 Computers
5. Video Patterns, Macintosh LC and LC II
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1. NEW FEATURE: "TstMd via ADB" — A Remedy for Incomplete Test Manager Entry!
Occasionally, a Macintosh LC II or Classic II computer may enter Test Manager mode by itself upon power-up. When this occurs, there is a chance that it will enter Test Mode “incompletely.” You can recognize this state by the following symptoms:
• "TstMd" will report that the CPU is in Test Manager mode,
-AND-
• "cpuID" will function correctly,
-BUT-
• "ROMck" and other logic tests will lose communications and ask you to “Check prior UUT functions.”
Because of the possibility of incomplete Test Mode entry, Apple® recommends re-entering Test Manager mode by using the new function "TstMd via ADB" whenever the computer enters Test Mode by itself upon power-up. (This function was added to the ROM pack too late to be documented in the Troubleshooting Guide for "CPU Tests, Vol. 2.")
To use "TstMd via ADB":
• If the Apple TechStep ADB1 and modem cables are connected to the computer, simply choose "TstMd via ADB" from page 3 of the HOME menu. (The computer can be in any state, off or on, when you choose “TstMd via ADB.”)
• If the ADB1 or modem port cable is not connected:
a) Switch off the Macintosh computer and Apple TechStep.
b) Connect the Apple TechStep ADB1 and modem ports (and any other ports you wish) to the corresponding Macintosh ports.
c) Switch on Apple TechStep, identify the CPU, and go to page 3 of the HOME menu.
d) Choose “TstMd via ADB.” Apple TechStep will issue a Reset command, and then an NMI command, via the ADB port.
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2. Parameter RAM Problems
Corrupted P/RAM can prevent an otherwise healthy Macintosh computer from booting. The computer enters Test Mode when switched on, but will either pass all Apple TechStep tests (LC) or enter Test Mode incompletely and prevent the tests from running (LC II, Classic II). Here’s how to diagnose and fix this situation.
FOR MACINTOSH LC: Computer will not boot but passes all tests:
To solve this problem, run the DESTRUCTIVE P/RAM Test as follows:
a) Choose "P/RAM" from the Logic menu. Choose "2-Destructive" from the P/RAM menu. If the test passes and reports "P/RAM erased," P/RAM should now be clear.
b) Run all Apple TechStep tests to verify that the computer is functional. If all tests pass, restart the Macintosh. If the computer boots normally, the problem was corrupted P/RAM and is now solved.
(Although testing is not complete at this date, we believe that this note applies also to the computers covered by CPU Tests, Vol. 1: Macintosh II, IIx, IIcx, SE, SE/30, and Classic.)
FOR MACINTOSH LC II AND CLASSIC II: Computer enters Test Mode by itself, and Apple TechStep tests lose communication:
In the Macintosh LC II and Classic II computers, corrupted data in the Parameter RAM can cause the computer to enter Test Mode “incompletely” when switched on. In this case, you will not be able to run the Destructive P/RAM test to erase the P/RAM until you re-enter Test Mode using the "TstMd via ADB" function.
a) With all power off, connect ADB1 and all other cables between Apple TechStep and the CPU.
b) Use TstMd via ADB to enter Test Manager mode.
c) Run all possible Apple TechStep tests.
• If all tests pass, run the P/RAM (Destructive) test. Then reboot the computer. If it boots normally, the problem was corrupted P/RAM data and is now solved. If the computer still does not boot, follow the troubleshooting procedures in the Technical Procedures.
• In very rare cases, after entering Test Mode using "TstMd via ADB", you may still find symptoms of incomplete Test Mode entry ("cpuID" functions correctly but ROMck tells you to “Check prior UUT functions”). This means that "TstMd via ADB" was unsuccessful, probably because of logic board problems. Replace the logic board.
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3. ERRATA for "CPU Tests, Vol. 2: Troubleshooting Guide"
Page 10, Manual Entry into Test Manager mode (Macintosh Classic II Computers Only):
Replace steps 2 and 3 with the following:
"2. As soon as you hear the boot tone, press the non-maskable interrupt (NMI) switch. (This switch has an interrupt icon. It is the rearmost of the two programmer’s switches.)"
Page 56, “RAM:Long”, “RAM All Tests” Warning Screens
Instead of the two warning screens shown in the Troubleshooting Guide, you will see a single warning screen as follows:
Test is 22min/MB
Can’t STOP test.
Use AC Adapter!
1-Start 2-Cancel
Remember that these tests will stop when any failure occurs. If they find a failure, they may take much less than the full 22 minutes per megabyte.
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4. Performa 200, 400 Computers
You can use "CPU Tests, Vol. 2" to test the Apple Performa 200 and 400 computers. For the Performa 200, use the Macintosh Classic II tests; for the Performa 400, use the Macintosh LC II tests.
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5. Video Patterns, Macintosh LC and LC II
The Video Patterns menu for Macintosh LC and LC II allows you to choose a "Gray/Color (4-bit)" pattern. This pattern displays green, blue, and “red” (actually magenta) stripes on a color monitor attached to the computer being tested.
Note that the “red” stripes in this pattern will actually appear magenta or pink.
Apple, the Apple logo, and Macintosh are trademarks of Apple Computer, Inc., registered in the U. S. and other countries. Performa and Apple TechStep are trademarks of Apple Computer, Inc.
