HYDRA
Service Manual
5A-18
Table 5A-6. Ohms Open-Circuit Voltage (2635A)
Range
Voltage
300
Ω
3 k
Ω
30 k
Ω
300 k
Ω
3 M
Ω
10 M
Ω
3V
1.3V
1.3V
3V
3V
3V
Table 5A-7. Ohms HI Troubleshooting (2635A)
Checkpoint
Signal Description
Possible Fault
A3U8 pin 14
Ohms Source
A3U8
A3R10 HI SRC
Ohms Source
A3R10, A3K16, A3RT1, A3Z4, A3Q10
Channel HI
Ohms Source
A3K1 through A3K14, A3U4, A3U5, A3U11, A3U12, A3L1,
A3L2, A3L3
A3U8 pin 23
Ohms Source
A3R11, A3K17, A3R42, A3C32
A3U8 pin 58
Ohms Source filter output
A3U8, A3Q2
5A-14. Digital Kernel Troubleshooting
At power-up, if the display does not light or lights up and fails to report errors or begin
operation, use the following troubleshooting procedures.
To determine the relative health of the MC68302 Microprocessor (A1U1), first check for
a valid system clock (SCLK) at TP11. Use an oscilloscope to check for the SCLK clock
at A1TP11. Look for a 12.288-MHz square wave that transitions from 0 to 5V dc (VCC).
•
If this signal is present, check for a similar waveform at pinA1U25-30 of the FPGA.
If a 12.288-MHz square wave is not presentthere, resistor A1R107 is probably bad.
•
If the SCLK signal (A1TP11) is something other than a 12.288-MHzsquare wave, it
is most likely that the problem is related to thecrystal oscillator circuit (A1U1,
A1Y1, A1C3, A1C8, or A1R2).
If the SCLK signal is good, check the Display Clock (DCLK) output from A1U25-19.
DCLK should have a frequency of 1.024-MHz (period of 976 nanoseconds). The DCLK
signal is not symmetrical; use an oscilloscope to verify that it is high for about 325
nanoseconds and then low for about 651 nanoseconds. The operation of the Display
assembly depends on the DCLK signal. Missing segments, intensified digits, a strobing
display, or a blank display can be caused by a faulty DCLK clock.
•
If the DCLK signal (A1U25-19) is not present but the SCLK signal iscorrect at
A1U25-30, the problem may be that A1U25 was notconfigured correctly at power-
up or A1U25 is defective.
•
If the OCLK signal (A1U25-22) is a 3.072-MHz square wave but the DCLKsignal is
wrong, A1U25 must be defective.
Содержание 2620A
Страница 4: ......
Страница 18: ...HYDRA Service Manual 1 2...
Страница 48: ...HYDRA Service Manual 1 32...
Страница 126: ...HYDRA Service Manual 3 2 3 30 Install the Handle and Mounting Brackets 3 15 3 31 Install the Instrument Case 3 15...
Страница 134: ...HYDRA Service Manual 3 10 Q Y U P J O A D B C V W G K L M E T X H I s25f eps Figure 3 5 2635A Assembly Details...
Страница 140: ...HYDRA Service Manual 3 16...
Страница 172: ...HYDRA Service Manual 5 2 5 28 Failure to Detect Memory PCA 5 29 5 29 Failure to Store Data 5 29...
Страница 234: ...HYDRA Service Manual 5A 34...
Страница 236: ...HYDRA Service Manual 6 2...
Страница 244: ...HYDRA Service Manual 6 10 A4 MP3 A4 H65 MP2 MP66 MP67 2620A 100 s58f eps Figure 6 1 2620A 2625A Final Assembly cont...
Страница 250: ...HYDRA Service Manual 6 16 A4 MP3 A4 H65 MP2 MP66 MP67 2620A 100 s62f eps Figure 6 2 2635A Final Assembly cont...
Страница 254: ...HYDRA Service Manual 6 20 2620A 1601 s63f eps Figure 6 3 2620A 2625A A1 Main PCA...
Страница 258: ...HYDRA Service Manual 6 24 2635A 1601 s64f eps Figure 6 4 2635A A1 Main PCA...
Страница 260: ...HYDRA Service Manual 6 26 2620A 4002 CKT 1 CKT 2 s65f eps Figure 6 5 A2 Display PCA...
Страница 265: ...List of Replaceable Parts Service Centers 6 6 31 2620A 1604 s67f eps Figure 6 7 A4 Analog Input PCA...
Страница 267: ...List of Replaceable Parts Service Centers 6 6 33 2620A 1605 s68f eps Figure 6 8 A5 IEEE 488 Interface PCA Option 05...
Страница 269: ...List of Replaceable Parts Service Centers 6 6 35 2625A 1606 s69f eps Figure 6 9 2625A A6 Memory PCA...
Страница 271: ...List of Replaceable Parts Service Centers 6 6 37 2635A 1606 s70f eps Figure 6 10 2635A A6 Memory Card I F PCA...
Страница 272: ...HYDRA Service Manual 6 38...
Страница 274: ...HYDRA Service Manual 7 2...
Страница 282: ...HYDRA Service Manual 7 10...
Страница 284: ...HYDRA Service Manual 8 2...
Страница 285: ...Schematic Diagrams 8 8 3 Figure 8 1 A1 Main PCA 2620A 2625A 2620A 1601 s88f eps...
Страница 288: ...Schematic Diagrams 8 8 6 Figure 8 1 A1 Main PCA 2620A 2625A cont 2620A 1001 3 of 4 s73f eps...
Страница 292: ...Schematic Diagrams 8 8 10 2635A 1001 2 of 5 Figure 8 2 A1 Main PCA 2635A cont s76f eps...
Страница 293: ...Schematic Diagrams 8 8 11 2635A 1001 3 of 5 Figure 8 2 A1 Main PCA 2635A cont s77f eps...
Страница 296: ...Schematic Diagrams 8 8 14 2620A 4002 CKT 1 CKT 2 Figure 8 3 A2 Display PCA s90f eps...
Страница 300: ...Schematic Diagrams 8 8 18 2620A 1003 2 of 3 Figure 8 4 A3 A D Converter PCA cont s82c eps...
Страница 301: ...Schematic Diagrams 8 8 19 2620A 1003 3 of 3 Figure 8 4 A3 A D Converter PCA cont s83c eps...
Страница 302: ...Schematic Diagrams 8 8 20 2620A 1604 Figure 8 5 A4 Analog Input PCA s92f eps...
Страница 304: ...Schematic Diagrams 8 8 22 2620A 1605 Figure 8 6 A5 IEEE 488 Interface PCA 2620A Only s93f eps...
Страница 306: ...Schematic Diagrams 8 8 24 2625A 1606 Figure 8 7 A6 Memory PCA 2625A s94f eps...
Страница 310: ...Schematic Diagrams 8 8 28...