Editing Apple Silentype Troubleshooting Guide

<templatestyles src="Template:StyledTable/styles.css" />
[[File:Apple Silentype rear label.jpg|thumb|360px|The rear label of a Silentype, naming Trendcom as the maker and warning to connect the cable only to the Silentype interface (photo: Christian Brockmann)]]
Fault-finding for the '''[[Apple Silentype]]''', from Apple's ''Silentype Printer Technical Procedures'' and the 1980 owner's manual. Apple's own repair limit was module level: its troubleshooting chart names the head cable, print head, deserializer card, platen, paper bearing assembly, paper drive motor and the belt and cord adjustments, and says to send the printer back to Apple if those do not cure it.<ref name="tp-ts">Apple Computer, Inc., ''Silentype Printer Technical Procedures'', Troubleshooting, p. 4.1 (rev. Feb 86, PDF p. 19), hosted as [[:File:Apple Silentype Technical Procedures.pdf]]; described at [[Apple Silentype Documentation]]. Source for: testing the Silentype with the Apple II Peripherals Diskette; the troubleshooting chart of symptoms and probable causes; returning the unit to Apple if the listed actions do not repair it.</ref> Adjustments and parts are on [[Apple Silentype General Maintenance]].

== The ERR message ==
From BASIC, the printer can report a serious problem by disconnecting itself and making the Apple print ERR on the screen. This usually means the Silentype cannot find its left margin.<ref name="man">Apple Computer, Inc., ''Silentype Printer Operation and Reference Manual'', 030-0095-00 (1980), Appendix A, Diagnostic Error Message, p. 44 (PDF p. 49), hosted as [[:File:Apple Silentype Operation and Reference Manual 030-0095-00 1980.pdf]].</ref>
# Disable the printer: press RESET, type PR#0 in BASIC, or type 0 Ctrl-P in the Monitor.
# Check that nothing blocks the print head's path.
# Check that the interface card is seated and the printer cable is plugged in properly. A badly installed printer can cause the message.
# If the printer still reports ERR, it needs service.

The left margin is found by the left margin switch, which connects to the deserializer card: one wire on early (non-EMI) printers, two wires on EMI printers.<ref name="tp-emi">''Silentype Printer Technical Procedures'', Take-Apart, Replacing the Deserializer Card, p. 1.11 (PDF p. 12), and Modifications, pp. 5.1-5.4 (PDF pp. 20-23).</ref> An EMI deserializer card fitted to a non-EMI printer without Apple's jumper modification gives an uneven left margin.<ref name="tp-emi" />

== Diagnostics ==
Apple's tests are on the Apple II Product Diagnostics disk, under CARD TESTS, then SILENTYPE TEST, with the interface card in slot 1. Answer N to the alignment prompt to reach the other tests.<ref name="tp-dx">''Silentype Printer Technical Procedures'', Diagnostics, pp. 3.1-3.5 (PDF pp. 15-18).</ref>

{| class="wikitable styled-table" style="width:100%; text-align:left;"
|+'''Silentype tests on the Apple II Product Diagnostics disk'''<ref name="tp-dx" />
! Test !! What it does !! What to look for
|-
| Align print head || Prints H's from margin to margin in both directions || Even left and right margins; smooth head travel. Uneven margins: adjust the Dacron cord. Uneven movement: adjust the drive motor belt.
|-
| Firmware || Checks the ROMs on the interface card || Reported on screen
|-
| RAM || Checks the RAM on the interface card || Reported on screen
|-
| Margin switch || Reports the state of the left margin switch || Reported on screen
|-
| Head movement || Moves the head back and forth || Smooth movement both ways
|-
| Line feed || Sends a line feed || Paper leaves squarely, without wrinkles or creases
|-
| Print head dot integrity || Prints one line for each of the seven head dots || Every line present
|-
| Print intensity || Prints six lines at eight intensities || A smooth range of darkness
|-
| Bidirectional registration || Prints parallel vertical lines in both directions || Lines within one dot of each other
|}

The troubleshooting section adds that the Silentype should be tested with the Apple II Peripherals Diskette, described in Apple's Multi-Product Diagnostics Technical Procedures.<ref name="tp-ts" />

== Troubleshooting chart ==
{| class="wikitable styled-table" style="width:100%; text-align:left;"
|+'''Apple's Silentype troubleshooting chart'''<ref name="tp-ts" />
! Symptom !! Probable causes, in order
|-
| Some dots do not print || Head cable; print head; deserializer card
|-
| One or more dots print all the time || Deserializer card
|-
| Wrong characters printed || Deserializer card
|-
| No head movement, or erratic movement || Belt tension adjustment
|-
| Print intensity test fails || Deserializer card
|-
| Will not print in both directions || Cord tension adjustment
|-
| Unreadable characters or none, though the head moves || Print head; platen assembly; deserializer card
|-
| Paper does not advance properly || Paper bearing assembly; deserializer card; paper drive motor
|}

== Things to check first ==
* Apple's manual says to use only specially treated thermal paper, fed under the roller, with the roll's bearings in the deepest notches.<ref name="man2">''Silentype Printer Operation and Reference Manual'', Checking the Paper, pp. 3-4, and Appendix A, Replacing the Paper, p. 43 (PDF pp. 8-9, 48).</ref>
* Old printouts that have darkened are not a printer fault: Apple notes that thermal paper darkens and becomes unreadable after several months.<ref name="man2" />
* A pink stripe on the paper edge means the roll is nearly finished.<ref name="man2" />
* Another card with a C800 ROM in the slot numbered one below the Silentype card can make the Apple send output to the wrong card.<ref name="man3">''Silentype Printer Operation and Reference Manual'', Plugging in the Interface, p. 5 (PDF p. 10).</ref>
* A platen fitted upside down, or a printer powered while loose in its base, can short and damage it; see [[Apple Silentype General Maintenance#Safety]].<ref name="tp-ta">''Silentype Printer Technical Procedures'', Take-Apart, Replacing the Print Head, p. 1.7, and Replacing the Deserializer Card, p. 1.11 (PDF pp. 8, 12).</ref>

== Related pages ==
* [[Apple Silentype General Maintenance]]
* [[Apple Silentype]]
* [[Apple Silentype Documentation]]

== References ==
<references />

{{Navbox-AppleVintageAccessories|state=collapsed}}

[[Category:Apple Vintage Accessories]]
[[Category:Apple Troubleshooting Guides]]
[[Category:Troubleshooting Guides]]