SECTION 10

MAINTENANCE & TROUBLESHOOTING

10.1 MAINTENANCE
  10.1.1 Power Supply
  10.1.2 Cables
  10.1.3 Probe Tip Assembly
10.2 TROUBLESHOOTING
10.3 PARTS LIST

10.1 MAINTENANCE

Maintenance of the EM-Series Diagnostic Emulator has be minimized by the extensive use of solid-state components throughout the instrument. There are only three areas where you need concern yourself with maintenance.
• Power Supply
• Cable
• Probe Tip Assembly
These are discussed in the following paragraphs. In addition, a troubleshooting chart follows, with section references for this manual.

10.1.1 POWER SUPPLY

The power supply provieds the necessary voltages to operate all of the logic contained within the Operator's Station, as well as the POD assembly. The power supply is a regulated supply that is adjustable via the potentiometer located on the regulartor PC board within the operator station. The +5 volt supply can be checked by using a Digital Volt Meter (DVM) and applying the ground probe to pin 12 of the ZIF PROM socket and the prositive probe to pin 24 of the ZIF PROM socket. The voltage can be adjusted with the potentiometer on the PC card.

To access the regulator PC card, remove the four exposed screws on the bottom of the Operator Station and then remove the top cover. The regulator PC card is located on the right-hand side of the instrument, with the potentiometer in the uppermost corner. Adjust the potentiometer to deliver 5.00 ± .05 VDC. If you cannot adjust the potentiometer to this specification, contact the Applied Microsystems Corporation Technical Services Department.

10.1.2 CABLES

The interconnect cables are the most vulnerable area of the instrument due to constant flexing during insertion and extraction. First, inspect the cables for any obvious damage, there may be broken wires within the cables (usually located close to the ends). A broken wire within the cable will cause the instrument to run erratically or intermittently if the cables are flexed during the "RUN" mode. By swapping the cables in question with a known good set of cables, you can easily isolate the faulty cable. The parts list at the end of this section contains cable part numbers if you need to order replacements.

10.1.3 PROBE TIP ASSEMBLY

The Probe Tip Assembly is the small DIP header assembly that plugs into the target system CPU socket. The most obvious area to inspect is the 40-pin adapter as the pins can be broken during insertion or extraction. If one of the pins should be inadvertently broken, you should replace the complete 40-pin adapter.

NOTE:

The 40-pin adapter can be protected by installing a CPU socket (male-female) onto the 40-pin adapter. If a pin is then broken on the CPU socket, it is easier to replace because of its common usage.

You should also inspect the probe tip assembly to see if any of the 1/8 watt resistors have been broken.

NOTE:

Due to the close physical tolerance surrounding the 1/8 watt resistors, we recommend that they be returned to the factory for repair.

10.2 TROUBLESHOOTING

Troubleshooting microprocessor-based equipment can be a complex process, due mainly to the complex nature of several peripheral devices, such as the data and address lines. To assist you in identifying the faulty PC card or possibly a component, your emulator is equipped with diagnostic test routines. The diagnostic programs are described in Section 7; if you need to perform any specific test, you should refer to the decription in Section 7. Before starting troubleshooting procedures, be sure that interconnect cables are installed properly in a compatible target system, with power applied to both the target system and the emulator.

The most common problems encountered are listed in Table 10-2. We recommend that you contact the Technical Services Department of Applied Microsystems Corporation if you experience any problems that do not fall within this range of items.

NOTE:

We do not recommend a component-level repair in the field, unless performed by a qualified service engineer.

Table 10.2 Troubleshooting

SYMPTOMPOSSIBLE CAUSESSECTION
Target system1. Faulty interconnect cables10.1
runs eratically2. Intermittent contact on*
  Probe Tip Assembly PC Card
3. Broken pin on 40-pin adapter3.3 10.1.3
4. Power supply out of adjustment1.4
5. "Hold-tites" on Probe Tip Assembly*
  missing (for connection to 40-pin adapter)
6. Broken resistor on Probe Tip Assembly10.1.3
7. Option switches set improperly9.2
8. RAM Overlay switch on but memory not programmed5.4

  *Call Applied Microsystems (Technical Services Department)
**Check Target System

Table 10.2 Troubleshooting

SYMPTOMPOSSIBLE CAUSESSECTION
9. Control PROMS on keyboard need to be reseated7.4 (D-D)
10. Emulator and target system not compatible1.1
11. Faulty address of data buffer7.1 (A-4)
  (see Code Function A4 and B2)7.2 (B-2)
Emulator will not1. Option switches for character9.2
communicate overformat set incorrectlly
RS-232 line2. Baud rate set incorrectly9.3
3. Target system requires a "null"9.1
  modem cable (pin 2 and pin 3 of9.3
  RS-232 connector reversed)
Target system will1. Cables plugged in wrong3.3
not run2. Power supply out of adjustment1.4
3. Faulty interconnect cables10.1
4. Broken pin on 40-pin adapter10.1.3 3.3
5. Broken pin on interconnect cable connector*
6. RAM Overlay switch on, but memory not programmed5.4
7. No clock in target system3.3
8. No power (+5 volts) in target system**
9. Option switches set improperly9.2
10. Emulator and target system not compatible1.1
11. RUN key bad*
12. Constant target reset3.3
13. Target system has one or more**
  DMA devices requesting the bus
  (Example: Bus Req line = True)

*Call Applied Microsystems (Technical Services Department)
**Check Target System

10.3 PARTS LIST

The following parts are avilable for you to order:

Part Number
40-Pin Adapter210-11410
Short Cable Set600-11284
Long Cable Set600-10653-01
Key Switch510-10128
Hex Display370-10009