Atari 1020 Maintenance Guide
The Atari 1020 Color Printer is an ALPS plotter mechanism with four pens in a rotating holder. Its upkeep is mostly mechanical: pens, the two small motor pinion gears, light lubrication and two adjustments of the pen solenoid. Atari's procedures are in the 1020 Color Printer Field Service Manual (FD100288 Rev. 01).[1] Faults are diagnosed on the Atari 1020 Troubleshooting page.
Preventive maintenance
[edit | edit source]Atari's preventive maintenance for every 1020 opened for service:[1]
- Clean dust and dirt from inside with a dry, soft cloth.
- Remove stains with alcohol or benzene. Do not use thinner, trichloroethylene or ketone solvents, which damage the plastic parts.
- Put one small drop of light oil on the pivot point of the ejector shaft, at the left front of the printer module.
- Put one small drop on the ejection roller, then move the slider unit back and forth a few times to spread it along the shaft.
- Check the actuator and coupling lever adjustment and the pen and paper platen adjustment.
Opening the printer
[edit | edit source]Unplug the adaptor first; Atari warns against any disassembly with the AC power connected.[1]
- Slide the top cover back to free its tabs from the bezel, lift it off and remove the paper roll.
- Turn the printer over and remove the two front rubber feet. The rear feet are glued on.
- Remove the two machine screws under the feet and the three other screws.
- Turn the printer the right way up and separate the upper case from the lower case by lifting the back of the upper case slightly.
- Pull the lower front of the bezel forward to free its hooks from the upper case, and set it aside.
- Set the upper case upside down in front of the lower case and remove the two screws holding the switch assembly, then the upper case.[1]
The upper case carries the buttons and the lower case the board, so the two open like a clam shell; the mechanism connects to the board by a ribbon cable.[2] To lift out the printer module, remove the screw at the right front holding the mounting plate, then disconnect the ground wire from the board.[1]
Pens
[edit | edit source]Load and change pens with the PEN and COLOR buttons. Press PEN to move the carriage to the change position; the silver wheel at the end of the carriage shows which colour goes in each slot. Pull the knurled white pen change lever towards you to pop a pen out, snap the new pen in with its tip in the hole in the silver wheel, press COLOR to move to the next slot, and press PAPER when finished. Holding PEN for more than three seconds sends the carriage home and prints the test squares.[3] Remove the rotary pen holder only when it is empty.[1]
Original pens have almost all dried out. Attempts to revive them have mixed results:
- The Tandy CGP-115 wiki, which covers the same ALPS mechanism, uses water-based dye ink (not India ink, whose pigment clogs the wick and ball), injected with an insulin syringe into the vent holes of new pens. It reports under half its attempts to revive original steel-barrel pens succeeded, after full disassembly and soaking.[4]
- New pens for this mechanism are made by a German medical supplies company.[4]
- Ultrasonic cleaning and refilling failed on one set of 1020 pens. Their owner then made pens from cut-down gel-pen refills in 3D-printed bodies, cutting each refill 2 mm shorter than the original cartridge; ordinary ballpoint refills needed more pressure than the pen mechanism gives.[5] Readers of that write-up report that the cut-down refills run out quickly because they lack the original pens' ink-holding wick.[5]
- Soaking two dried pens in hot water failed to revive them in another repair.[2]
Store pens and ink in metal or glass containers; water and alcohol escape from the ink through ordinary plastic bags and boxes over time.[4]
Motor pinion gears
[edit | edit source]The small nylon gears on the shafts of the carriage and paper feed motors shrink with age and split. A cracked paper-feed gear stops the plotter drawing accurate vertical lines, and a cracked carriage gear stops the pens moving back and forth; one new-in-box 1020 had both gears cracked.[6][4]
| Teeth | Module | Bore | Length |
|---|---|---|---|
| 13 | 0.25 | 1.5 mm | 4.5 mm |
Replacements are machined brass or 3D printed.[4] On the 1020 the paper-feed pinion is the smallest of the three gears on the right; it slides off the shaft and the new one slides on.[6] When pressing on a brass gear, support the motor shaft with a vice with plastic jaws, and keep metal jaws away from the rear end of the shaft, which sits close to the bearing and deforms easily.[4]
Atari's motor removal, if needed: lift off the motor cover with a flat screwdriver, unhook the paper holding roller support plate spring, remove the screw holding the motor, prise the motor out without bending the frame, desolder the jumper between the two motor boards, and desolder the reed switch wires (yellow and grey, carriage motor) or the electromagnet wires (red and black, paper feed motor). On refitting, check that the gears mesh and that the harness is threaded as before.[1] When removing the print head idle gear, move the bobbin gear aside without removing it, and do not cross or unwind its wire.[1]
Pen solenoid adjustments
[edit | edit source]Make both adjustments whenever the electromagnet assembly is replaced.[1]
| Adjustment | Condition | Gap | How |
|---|---|---|---|
| Actuator and coupling lever | Pen fitted, actuator pulled out to the pen-down position | 0.1-0.2 mm between actuator and coupling lever | Set, then tighten the screw holding the electromagnet assembly to the frame |
| Pen and paper platen | Actuator pulled to the pen-up position | 0.6-0.7 mm between pen tip and platen | Turn the stopper screw; anticlockwise widens the gap |
Keep magnetic objects away from the electromagnet assembly.[1]
Paper
[edit | edit source]Load the roll so that it feeds from the bottom, trim the leading edge straight, feed it into the slot at the bottom of the paper well and turn the roller until it appears, making sure it passes under the two brass pinch rollers.[3] The paper is about 4.5 inches (11.5 cm) wide.[7] The right-hand paper holding roller is grooved and the left one smooth, which matters when replacing them.[1]
Related pages
[edit | edit source]- Atari 1020
- Atari 1020 Troubleshooting
- Atari 1020 Capacitor Replacement Guide
- Atari 1020 Documentation
- Recommended Tools
References
[edit | edit source]- ↑ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 Atari, Inc., 1020 Color Printer Field Service Manual, FD100288 Rev. 01, August 1983. Preventive maintenance and adjustments (p. 6-1); case and printer module removal (p. 6-4); electromagnet removal and the actuator and coupling lever adjustment (p. 6-5); pen and paper platen adjustment (p. 6-6); motor removal (p. 6-8); rotary pen holder and stopper click (p. 6-9); idle gears, ejection lever spring and paper holding rollers (pp. 6-10 and 6-11); parts list (p. 7-1). Hosted here as File:Atari 1020 Color Printer Field Service Manual FD100288 Rev 01.pdf.
- ↑ 2.0 2.1 RetroNerd, "Atari 1020 Colour Printer Plotter Repair", 7 January 2024. retronerd.co.uk. Community repair write-up.
- ↑ 3.0 3.1 Atari, Inc., The Atari 1020 Color Printer Owner's Guide (1982), loading pens and changing pens pages. Hosted here as File:Atari 1020 Color Printer Owner's Guide.pdf.
- ↑ 4.0 4.1 4.2 4.3 4.4 4.5 Tandy Tech wiki, "CGP-115", sections on pens, gears, refilling pens and pen and ink storage (last edited 1 August 2026). tandy.wiki. Community reference.
- ↑ 5.0 5.1 drygol, "Atari 1020 Plotter – plotting pens replacement", retrohax.net, 2 February 2024, with reader comments. retrohax.net. Community repair write-up.
- ↑ 6.0 6.1 Jason H. Moore, "Repair an Atari 1020 Printer (30-60 mins)", Atari Projects, 25 August 2018. atariprojects.org. Community repair write-up.
- ↑ Wikipedia, "Atari 1020". en.wikipedia.org.