Apple Scribe Printer Troubleshooting Guide
Fault-finding for the Apple Scribe Printer, from section 4 of Apple's Apple Scribe Printer Technical Procedures. Apple's method is to make the initial checks, run the self-test, and work through the symptom tables, replacing one module at a time and putting the original back if the replacement does not cure the fault. Every repair must pass the self-test. If a symptom is not in the tables, Apple's instruction is to replace the logic board, which "can cause the greatest variety of symptoms".[1] Adjustments and lubrication are on Apple Scribe Printer General Maintenance.
Initial checks
[edit | edit source]Inspect before testing:[1]
- Power cord: cracked insulation, signs of burning, kinks from bending, a missing earth pin.
- Case: burn marks, signs that the owner has opened it, cracks in the case, paper tray or cover from a drop.
- Ribbon cassette: missing, used up or torn ribbon; broken ribbon drive cable.
- Print head: damage; head cable fitted wrongly.
- Platen: dirt or damage, labels stuck to it, paper or labels stuck in the feed path.
Then load paper and run the self-test: hold LINE/FORM FEED while switching on. The printer should print a repeating alphanumeric pattern.[1] The loopback test, which also checks the ROM, RAM and serial lines, is described on Apple Scribe Printer#Self-test and loopback test. To run either test with the cover off, defeat the cover interlock switch, to the left of the SELECT and LETTER switches, with a wedge of rolled paper or another non-metallic object.[2]
SELECT lamp codes
[edit | edit source]| SELECT lamp | Error | Corrective action, in order |
|---|---|---|
| Flashes slowly | Paper end | Load paper; paper inserted too far to the right; clean the paper detect sensor; logic board; mechanism assembly (faulty paper detect sensor) |
| Flashes rapidly | Ribbon end | Remove and reseat the ribbon cassette; fit a new cassette and press SELECT; mechanism assembly (faulty out-of-ribbon sensor); logic board |
| Three rapid flashes, pause, three more | RAM check | Logic board |
| Two rapid flashes, pause, two more | Home position (left margin) | Check that the nut on the left drive belt pulley is not overtightened; check the carriage belt tension; mechanism assembly |
| One flash, pause, one flash | Loopback test | Check that the loopback connector is fitted firmly; logic board |
| Flashes very fast, printer does nothing | No error condition | Replace the ribbon; logic board |
| Lit steadily, carriage does not move | Check the baud rate DIP switch setting; interface cable; logic board |
Print quality
[edit | edit source]| Symptom | Corrective action, in order |
|---|---|
| Print is light | Paper type suitable; DIP switch setting suits the paper; new ribbon cassette; ribbon drive wire connected and drive pulley turning; print head clean; print head gap; print head; ribbon drive wire; logic board |
| Print is dark | DIP switch setting suits the paper; print head; logic board |
| Density varies on any paper | New ribbon cassette; ribbon feed mechanism (mechanism assembly if faulty); ribbon drive wire |
The print head gap is 3.5 mm ±0.5 mm. A head too far from the platen prints uniformly light; too close, it prints too black with a grey smear. Uneven vertical lines away from the left margin come from wrong drive belt tension; a slight unevenness at column 0 is normal.[3] Both adjustments are on Apple Scribe Printer General Maintenance.
Abnormal operation
[edit | edit source]| Symptom | Corrective action, in order |
|---|---|
| Control panel keys do not work | Control panel cable connector CN7 firmly on the logic board; control panel; logic board |
| Prints with no paper loaded | Clean the paper detect sensor; mechanism assembly (faulty sensor); logic board |
| Carriage hits the end of its travel | Nut on the left drive belt pulley not overtightened; drive belt tension; home position switch (mechanism assembly if faulty); connector CN8 firmly connected; logic board |
| Carriage moves to the centre and stops at switch-on | Load paper and/or a ribbon cassette; logic board |
| Carriage moves to the right at switch-on and stops | Logic board |
| Head taps the platen once at switch-on and the printer does nothing | Logic board |
| Head taps the platen once at switch-off and the printer does nothing | Logic board |
| Head engages the platen and stays there | Logic board; check the print head after replacing the board |
| Carriage jumps once at switch-on, then nothing | Logic board |
| Platen roller feeds backwards when power is removed, printer does nothing | Logic board |
| Carriage jumps about at switch-on, then stops | Logic board |
Before blaming the printer
[edit | edit source]- Paper is the first suspect for poor print: Apple's procedures say the Scribe works best with smooth bond paper and that the paper should be examined first and the best bond paper used for tests.[4]
- The DIP switches 5 and 6 set the density for paper or transparencies; a wrong setting gives light or dark print.[4]
- Software written for the ImageWriter may not support every feature; some programs, such as AppleWorks, need a Scribe driver.[5]
- The loopback test does not test the handshake (DTR or XON/XOFF) circuits, so a printer can pass it and still fail to handshake with the computer.[2]
Related pages
[edit | edit source]References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Apple Computer, Inc., Apple Scribe Printer Technical Procedures, Section 4, Troubleshooting, pp. 4.1-4.15 (PDF pp. 40-48), hosted as File:Apple Scribe Technical Procedures.pdf; described at Apple Scribe Printer Documentation. Source for: testing with the Apple II Peripherals Diskette; the initial checks; the self-test; the equipment list (Phillips and flat-blade screwdrivers, needle-nose pliers, ruler, loopback connector, IC extractor 918-0017, tension gauge 077-0014); how to use the symptom tables; the SELECT lamp error patterns; the symptom tables for error conditions, print quality and abnormal operation.
- ↑ 2.0 2.1 Apple Scribe Printer Technical Procedures, Section 1, Basics, Printer Self-Test and Loopback Test, pp. 1.6-1.7 (PDF pp. 7-8).
- ↑ Apple Scribe Printer Technical Procedures, Section 3, Adjustments, pp. 3.3-3.7 (PDF pp. 37-39).
- ↑ 4.0 4.1 Apple Scribe Printer Technical Procedures, Section 1, Basics, Paper Requirements, p. 1.5 (PDF p. 6).
- ↑ Apple Scribe Printer Technical Procedures, Section 1, Basics, Configuration Requirements, p. 1.3 (PDF p. 4).