Fluke Comprehensive Service Manual for the 8842A Portable Multimedia Player

8842A

Instruction Manual

PORT BIT

	Table 6-25. I/O Port Configurations
CONFIGURATION				CONFIGURATION
Static		Read/Write	PORT BIT	Static	Read/Write
Dynamic				Dynamic

PO-0

PO-1

PO-2

PO-3

PO-4

PO-5

PO-6

PO-7

P2-0

P2-1

P2-2

P2-3

P2-4

P2-5

P2-6

P2-7

NOTES:

OUT OUT OUT OUT IN IN IN IN

IN

IN

IN

IN

IN

IN

IN

IN

Address

Address

Address

Address

IN

IN

IN

IN

IN

IN

IN

IN

IN

IN

IN

IN

P1-0

P1-1

P1-2

P1-3

P1-4

P1-5

P1-6

P1-7

P3-0

P3-1

P3-2

P3-3

P3-4

P3-5

P3-6

P3-7

OUT OUT OUT OUT OUT OUT OUT OUT

IN

IN

IN

IN

IN

IN

Clock serial

Data

Data

Data

Data

Data

Data

Data

Data

IN

IN

IN

IN

IN

IN

Clock Serial

∙Due to external hardware conflicts, the following bits are NEVER driven by the Out-Guard μC in ANY diagnostic mode: P0-4,5,6,7; P2 (all bits); P3-1,2,3,4.

∙P3-6 is the 4 MHz clock for the NEC7210 IEEE chip (U901).

∙P3-7 is programmed as the serial output, and constantly transmits hex 55 every 820 μs at 62,000 baud in all four diagnostic modes. This causes the front panel error message.

6-71. True RMS AC Troubleshooting (Option -09)

6-72. SERVICE POSITION

To provide easy access to the True RMS AC PCA and the Main PCA, the True RMS AC PCA can be placed in the specially provided service position as follows:

1.Remove the case from the chassis using the Case Disassembly procedure provided earlier in this section.

2.Release the four nylon latches that hold the True RMS AC PCA in place by pulling the latches upward. (See Figure 809-1E in Section 8.)

3.Disconnect the red ac input lead from both the True RMS AC PCA and the Main PCA.

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