1. AN INTRODUCTION TO TROUBLESHOOTING Troubleshooting is usually to easy; vaned symptoms appear depending on points of failure. This section decribes two procedures which may allow easier troubleshooting and subsequent repair: 1. Check-out procedure Objective: To guide the user through a problem isolation process when symptoms do not indicate a specific component malfunction. Fault isolation level: Repair by ;unit replacement, repair can be accomplished with a basic knowledge of computer hardware. 2. Unit repair flowchart Object: To guide the user through a component level repair process. Allow component-level repair of an individual faulty unit. Fault isolation level: Component level- Requires an advance knowledge of computer hardware engineering, and electronic. General troubleshooting procedure * First, isolate and replace the faulty unit according to the check-out procedure, each time a unit is replaced, to make sure the new unit is not faulty. This procedure will prevent confusion with a problem caused by a poor connector contacts. * Second, isolate and replace the faulty component in the unit according to the unit flowchart or the troubleshooting table. Step 1 Step 2 ---------------- ---------------- ( Check-out ) ---\ ( Unit repair ) ( procedure ) ---/ ( flowchart ) ---------------- ---------------- Repair by unit repair at com- replacement ponent level NOTE 1) All checks indicated on the flowchart must be made. Should any unit or component be replaced disregarding any check, the newly installed one might be damaged. NOTE 2) Whenever you are lost in the repair procedure, return to the entry and restart the procedure. NOTE 3) When no exit is found, during a diagnostic procedure (e.g., the test procedure has resulted in repeating a diagnostic loop), proceed with the repair according to the trouble table. 2. TEST PROGRAM The test program provides tests for the ten functions listed in Table 1. It allows either one of the following two execution modes: * AUTO Mode In this mode, the program automatically performs a six test cycle. If desired, the cycle may be repeated up to 99 times. The number of cycles may be selected after loading the program. This mode is suitable for an aging test after repair or a test on a problem of very low reproducibility. * MANUAL Mode The manual mode allows the user to select any one test from those listed in Table 1 and is an aid to component troubleshooting. 1 Table 1: Functions tested by the program ---------------------------------------- No. Tested Function ---------------------------------------- 1 RAM CHECK 2 BUZZER CHECK 3 RS,SER CHECK 4 LCD CHECK 5 MCMT CHECK 6 DIP-SW READ CHECK 7 KEY BOARD CHECK 8 ANALOG INPUT CHECK 9 BARCODE CHECK 10 CLOCK CHECK 2.1 REPAIRING TOOLS Table 2, lists necessary repair tools which are available from EPSON. Table 2: REPAIR TOOLS QTY ------------------------------------------------------- 1 Test program 1 2 RS-232C interface mini-wrapping connector 1 3 Serial interface mini-wrapping connector 1 4 Microcassette tape 1 5 Cable assembly (P/N B778400201) 1 6 DC regulator or dry-cell battery 1 7 Low-resolution barcode reader 1 2.3 LOADING THE TEST PROGRAM Set the POWER switch ON and load the program. After the above preparation, the following menu will appear on the LCD pannel. --------------------------------------------------- | TEST PROGRAM MENU MODE Ver 1.0 | | | | 1 : AUTO | | 2 : MANUAL | --------------------------------------------------- 2.4 SELECTING A TEST MODE In the responce to the menu, key in "1" or "2", respectively, to select the AUTO or MANUAL test mode. * AUTO mode When the AUTO mode is selected ("1" is keyed in), the prompt: --------------------------------------------------- | CHECK COUNT ? | --------------------------------------------------- should appear. Specify a number of test cycles to be run by responding with a number from 1 to 99. RAM, buzzer, RS-232C interface, serial interface, LCD unit, microcassette tape drive and DIP switche test make up one test cycle. When the AUTO mode is selected, this cycle is repeated according to the number of times specified in the response to the prompt. 2 * MANUAL Mode --------------------------------------------------- | TEST PROGRAM SELECT | | 1.RAM CHECK 2.BUZZER CHECK | | 3.RS,SER CHECK 4.LCD CHECK | | 5.MCMT CHECK 6.DIP-SW READ CHECK | | 7.KEY BOARD CHECK 8.ANALOG INPUT CHECK | | 9.BARCODE CHECK 10.CLOCK CHECK | --------------------------------------------------- Select a test by keying in the number preceding the test. When the test is completed, the display stops. To repeat the test again, press the apace bar, otherwise, press the RETURN key. To stop the test after the keyboard check has been selected, key in "Break". * If any error message appears, refer to section 2.6 2.5 TEST RUN PROCEDURE AND DISPLAY INFORMATION This section describes the procedure for running the individual tests and display information given by them. ---------------------------------------------- | | | MEMORY & V-RAM CHECK | | | ---------------------------------------------- (1) RAM Check The RAM and V-RAM check tests are performed in succession and the following messages are displayed when the tests are completed. ---------------------------------------------- | RAM CHECK END !! | | VRAM CHECKING !! | | VRAM CHECK END NOW !! | ---------------------------------------------- (2) Buzzer Check * The buzzer sounds for approximately three seconds. * The buzzer further sounds at two different tones and then the following is displayed: ---------------------------------------------- | BUZZER OK ? | ---------------------------------------------- * Adjust the sound level and do another check. (3) RS-232C and Serial Interface Check Step 1: Insert the RS-232C interface and the serial interface connectors, which are connected according: Serial interface RS-232C interface ---------------- ----------------- 4 shorted to 5 6 shorted to 7 2 shorted to 3 2 shorted to 3 4 shorted to 5 shorted to 8 (The sockets are labeled on the PX-8 case.) 3 Step 2: Key in "3" for the test menu (TEST PROGRAM SELECT). The RS-232C and the Serial Interface Check will be selected. The program runs the RS-232C interface test first, displaying the following information: --------------------------------------------------- | RS232C CHECKING | | RS232C CHECK END NOW | --------------------------------------------------- Step 3: The program then runs the serial interface test and display the following information: --------------------------------------------------- | HIGH SPEED SERIALING | | HIGH SPEED SERIAL END NOW !! | --------------------------------------------------- Step 4: These messages indicate the end ot the test. (4) LCD Check * The entire LCD panel display is reversed. * The LCD panel dispaly is reversed every other dot and then the black and white conbination is reversed. * The LCD panel display is reversed every four dots and then the black and white conbination is reversed. * The following character pattern appears, and the test ends. --------------------------------------------------- | ***** CHRAGENE TEST | | !"#$%&'()*+,-./0123456789:;<=>?@ABC...XYZ... | --------------------------------------------------- (5) MCMT (Microcassette Tape Drive) * The following prompt appears: --------------------------------------------------- | SPEAKER ON ? (Y/N) | --------------------------------------------------- If speaker sound output is desired, depress "Y" (YES); if not, press "N" (NO), and the next prompt will appear as follows: --------------------------------------------------- | IS THIS TAPE INITIALIZE ? (Y/N) | --------------------------------------------------- Examine the tape and respond with "Y" to this prompt if the tape data may be destroyed. Otherwise, key in "N". * A Rewind/Fast Feed and Read/Write check test are performed after the following information message is displayed: --------------------------------------------------- | MCMT CHECK (REWIND, F.F & READ/WRITE CHECK) | --------------------------------------------------- * The third prompt appears as follows: --------------------------------------------------- | WRITE TAPE INFORMATION TO THIS TAPE ? (Y/N) | --------------------------------------------------- * The test ends with the following information message: --------------------------------------------------- | WRITE DATA & STOP | | HEAD OFF | --------------------------------------------------- 4 (6) DIP SW Read Check The following information is displayed: ------------------------ | 87654321 | DIP switch SW4 elements 1 - 8 | INITIAL=00101111 | Element setting | 00101111 | ------------------------ * Make sure that the DIP switcj setting agrees with the following table. DIP Switch Settings ------------------------------------------------- | Character set specification | 1 2 3 4 5 6 7 8 | |-----------------------------|-----------------| | ASCII (USA) | 1 1 1 1 0 1 0 0 | | French | 0 1 1 1 0 1 0 0 | | German | 1 0 1 1 0 1 0 0 | | English | 0 0 1 1 0 1 0 0 | | Danish | 0 1 0 1 0 1 0 0 | | Swedish | 0 1 0 1 0 1 0 0 | | Norwegian | 0 1 1 0 0 1 0 0 | | Italian | 1 0 0 1 0 1 0 0 | | Spanish | 0 0 0 1 0 1 0 0 | | HASCI | 0 0 0 0 0 1 1 0 | | Japanese(Japanese language) | 1 0 0 0 0 1 0 0 | | Japanese(kana) | 0 0 0 0 0 0 0 0 | | Japanese(touch 16) | 1 0 0 0 0 0 0 0 | ------------------------------------------------- (7) KEYBOARD CHECK Step 1: Select your keyboard type by responding with the number following the specification of your unit. The following display prompt will appear: -------------------------------------------------- | THEN DSP DATA KEY-IN !! | -------------------------------------------------- Step 2: In responce to the above prompt, key in characters to be displayed in the following order: 1- ESC 13- 1 25- 7 37- 49- F 61- ; 2- PAUSE 14- TAB 26- Y 38- 50- C 62- . 3- HELP 15- 2 27- 8 39- BS 51- G 63- : 4- PF1 16- Q 28- U 40- 52- V 64- / 5- PF2 17- 3 29- 9 41- 53- H 65- RETURN 6- F3 18- W 30- I 42- CTRL 54- B 66- SHIFT 7- PF4 19- 4 31- 0 43- A 55- J 67 \ 8- PF5 20- E 32- O 44- SHIFT 56- N 68- GRAFT 9- [ 21- 5 33- - 45- S 57- K 69- CAPS LOCK 10- ] 22- R 34- P 46- Z 58- M 70- SPACE 11- INS 23- 6 35- ^ 47- D 59- L 71- CTRL 12- DEL 24- T 36- @ 48- X 60- , When the key data entry ends, the following prompt appears. -------------------------------------------------- | ONCE MORE KEY-BOARD CHECK ? (Y/N) | -------------------------------------------------- 5 Step 3: If the keyboard check, part 2, test is desired, respond with "N" to this prompt. Otherwise, key in "Y". The above part 1 test will be repeated. * The program enters the part 2 test and displays the following prompt: --------------------------------------------------- | KEY-BOARD CHECK Part 2 | | PUSH KEY-IN !! | --------------------------------------------------- Step 4: Key in the same characters as randomly displayed, following the above prompt. Step 5: To terminate the test, key in "break". The program will end the test leaving the following information message: --------------------------------------------------- | KEY-BOARD CKECK Part 2 END !! | --------------------------------------------------- (8) Analog Input Check Step 1: Connect a DC voltage regulator (output voltage range should be from 0v to +2.0v) and a dry-cell battery. Use the cable assembly P/N B778400201 acccording to the instructions in section 2.5 - 3. * The program displays the connected voltage at an accuracy of 0.02v. Step 2: When a DC voltage regulator is used, compare the displayed value with the reading. If a dry-cell battery is used, measure and cmpare its voltage. (9) Barcode Check * The following is displayed: --------------------------------------------------- | INPUT | --------------------------------------------------- Step 1: Read the barcde pattern using a reader. * If the pattern and read data agree, "OK" appears on the LCD panel. (10) Clock Check * The following prompt appears: --------------------------------------------------- | TIME SET ? (Y/N) | --------------------------------------------------- Step 1: If you would like to set the time, respond with "Y" to this prompt; otherwise, key in "N". *When "Y" is keyed in above, the time setting guide message is displayed: ---------------------------------------------------------- | INPUT DATA Year/ Month/ Day/ Hour: Minute: Sec/ Week | | Week Data Code | | Sun:00 Mon:01 Tue:02 Wed:03 Thu:04 Fri:05 Sat:06 | ---------------------------------------------------------- Step 2: Key in the date and time as follows: year,month,day,week,day,hour,minute, and seconds. * The set time should be updated every one second. 6 2.6 TEST PROGRAM MESSAGES The test program displays a message on the LCD panel when it terminates normally. When any malfunction is found, a diagnostic code indicates the problem area. Major error messages are explained in the following: (1) Return codes from slave CPU6303 --------------------------------------------------- | EPSP ERROR !! XX | --------------------------------------------------- The slave CPU operation being performed when an error occurs is indicated on the LCD panel as a one-byte "XX" return code. The following table lists all the available return codes and summarizes their meanings. Device Code Meaning ---------------------------------------------------------------------- SYS | 00 | Normal processing termination SYS | 01 | Break ACK: | | Indicates that a break took place. SYS | 02 | Command error: | | Indicates that a command has been input which is | | not included in the defined system. SYS | 03 | Communication error: | | Indicates that a command is received when data | | was to be received/sent or vise versa. 2CD | 11 | Illegal size: | | Indicates that a screen-over occured which is | | attributable to an illegal size specification. 2CD | 12 | An undefined graphic character was used. 2CD | 13 | An alphabetic character code was used. Or, an | | attempt was made to define any other than that | | for alphabetic character. MCT | 41 | Head error: | | Indicates that the head failed to operate normally. MCT | 42 | The tape stopped during processing. MCT | 43 | Write protect error: | | An attempt was made to write a tape with no | | write protect pin. MCT | 44 | Data error: | | Indicates that the data could not be determined | | to be either 1 or 0 because the data pulse is | | wider or narrower that the standard value. MCT | 45 | CRC error. MCT | 46 | Block mode error: | | A block whose identifer is other that that | | specified. ESPS | 61 | A linkage failed. ESPS | 62 | Communication error: | | Overrun or framing error. ESPS | 63 | Timer over. BEEP | 71 | Beep already in progress: | | Indicates that a BEEP or MELODY was attempted when | | another BEEP or MELODY was already in progress. ---------------------------------------------------------------------- 7 (2) Ram error message: --------------------------------------------------- | ERROR !! ADDRESS ****H | | WRITE DATA **H READ DATA **H | --------------------------------------------------- D-RAM compare error - Written and read-back data did not agree. --------------------------------------------------- | ERROR !! BEFORE ADDRESS ****H | | SAVE DATA ** READ DATA **H | --------------------------------------------------- D-RAM compare error - The RAM test was attempted on a program area (including OS, TPA, and RAM files) no read/write test is allowed. --------------------------------------------------- | VRAM ERROR ADDRESS ****H | | WRITE **H READ **H | --------------------------------------------------- V-RAM compare error - Written and read-back data did not agree, (3) RS-232C and Serial Interface error message --------------------------------------------------- | RS232C CHECK TIME OUT !! | --------------------------------------------------- RS-232C transmission/reception failure- DIR > DSR, RTS > CTS > CD, TXD > RXD. --------------------------------------------------- | RS232C ERROR TRNSMIT ****H RECIVE ****H | --------------------------------------------------- RS-232C transmitted/received data failed to agree. --------------------------------------------------- | ERROR CODE ** | --------------------------------------------------- RS-232C error XX occured: 08-Parity error 10-Overrun error 20-Framing error --------------------------------------------------- | HIGH SPEED SERIAL I/O ERROR !! | | TRANSMIT DATA ****H RECIVE DATA **** H | --------------------------------------------------- Data transmitted/received via the serial interface failed to agree. (5) MICROCASSETTE error messages --------------------------------------------------- | MCMT INITIALIZE (READ ERROR) TIME UP !! | --------------------------------------------------- Microcassette tape initialization failure - possibly a machanical fault. 8 --------------------------------------------------- | MCMT WIND &F.F. TEST CHECK COUNT **** | | RESULT COUNT **** | --------------------------------------------------- Tape count (photo-reflector output) error during rewind/fast feed. --------------------------------------------------- | MCMT READ/WRITE CHECK HEAD ERROR !! | --------------------------------------------------- Read/write head loading/unloading failure. --------------------------------------------------- | MCMT READ/WRITE CHECK TAPE STOP ERROR !! | --------------------------------------------------- Tape feed failure during read/write - the reel stops rotating. --------------------------------------------------- | MCMT READ/WRITE CHECK ERROR !! | | RDC ERROR !! CORE ** | --------------------------------------------------- Read/write error - possibly an abnormal tape feed speed or improper read/write pulse width. --------------------------------------------------- | MCMT READ/WRITE CHECK READ ERROR !! | | READ ** WRITE E5 | | BLOCK COUNT **** TO **** | --------------------------------------------------- Compare error - written and read-back data failed to agree. --------------------------------------------------- | THIS TAPE CAN'T WRITE | | CHANGE ANOTHER TAPE !! | --------------------------------------------------- Write failure. --------------------------------------------------- | LET'S CHANGE THE MC-TAPE | --------------------------------------------------- Read failure. --------------------------------------------------- | ONCE MORE KEY-IN !! | | KEY-CODE ERROR !! | --------------------------------------------------- Key entry code mismatch - a key code other than the specified one was input. Up to five key entry retrials are allowed. (6) Barcode error message --------------------------------------------------- | FOUND ***** | | BARCODE ERROR CHECK ERROR | | TRY ONCE MORE !! | --------------------------------------------------- Barcode pattern read failure. 9 3. UNIT LEVEL TROUBLESHOOTING When trouble-shooting a faulty unit, first find the entry routine for that unit from the entry table. In such a case where there are more that one symptom is observed and symptoms vary during the course of troubleshooting, make it a practice to enter troubleshooting procedures according to the symptom that occurred first. Notes on using the flowcharts: 1) The troubleshooting flowcharts do not necessarily include all information required for troubleshooting such as check modes,etc. Thus, the flowchart context and trouble symptoms should be closely examined. 2) I troubleshooting flowchart instructions lead you into a loop or to the end of a procedure and the problem is not resolved, refer to the schematic drawings or procedeed by troubleshooting according to the following procedure. Step 1: Replace the faulty unit with a good one and make sure that the faulty unit is really malfunctioning. Step 2: If the problem is difficult to reproduce or occurs so briefly that it is hard to examine the symptom, vary the supply voltage according to the following instructions. (a) Disconnect the battery from the battery connector CN2. (b) Prepare a variable (0-10)DC voltage regulator and make sure that the output is turnrd off. (c) Connect the regulator to the CN2 connector in place of the battery. (d) Adjust the regulator output voltage to +5V. (e) Turn the regulator output on. After the above setup is completed, vary the regulator output in a range from 4.8V to 6.0V and examine the unit operation at each voltage level. If this voltage margin test is successful, maintain the voltage and proceed with troubleshooting, using the check-out procedure and troubleshootng flowchart. 10