Atari 130XE General Maintenance

Atari 130XE

This is the maintenance guide for the Atari 130XE, and the reference for the rest of the XE line: the 65XE and 800XE pages cover what differs on those machines and refer back here.

Part numbers and the colour adjustment are from Atari's parts list and production test instructions for the 130XE. The power supply description, connector pinouts, disassembly and self test are from a 2016 reproduction of Atari's field service manual, with Sams' service data as a cross-check.

Power supply

The 130XE takes +5 V DC from an external supply through a 7-pin DIN socket, J7 (Atari part C061838). Pins 1, 4 and 6 are +5 V, pins 3, 5 and 7 are ground, and pin 2 is the shield. Atari's supply for the XL and XE machines is part C061982, rated 5 V DC at 1.5 A; the manual reproduction gives its output as 5 V ±5 %, so a healthy reading is 4.75–5.25 V.

The rectifier and regulator are inside the supply, not on the board. The reproduction draws it with a fuse F1, transformer T1 (115 V or 230 V AC in, 9 V AC out), bridge rectifier D1, a 4700 µF capacitor C1, an LM78S05 regulator U1 and a 100 µF output capacitor C2.

• Measure the supply's output before plugging it into the computer, every time you bring an unknown machine into service. Sams' method: unplug it from the computer and measure between pins 3 and 1 of the plug.
• If a supply has failed, check the computer for a short at J7 before fitting a replacement. With the power switch S1 on, check for a short between pins 3 and 1 of the socket; if there is one, repair it first.
• The FAQ reproduces B&C ComputerVisions' notes on the four versions of the C061982 supply. It says the solid black "ingot" version can damage the computer if it fails and is not switched off quickly, and advises disconnecting it if hum bars appear on the screen.
• A replacement supply must deliver regulated 5 V DC on a 7-pin DIN plug wired as above. The FAQ notes that a supply with a higher current rating than specified is usable and often preferable, because it runs cooler.

Opening the machine

This is the reproduction's sequence; Sams gives the same steps.

1. Turn the console upside down and remove the four screws holding the bottom cover to the top cover.
2. Turn it right side up, lift off the top cover and carefully disconnect the keyboard cable.
3. Remove the seven screws holding the shielded board, and lift the assembly out.
4. Unbend the seven shield tabs to separate the top and bottom shields from the board.

When reassembling, keep the adjustment holes in the shield clear, and make sure the locating stakes in the bottom cover go into their holes in the board before tightening anything. The keyboard is held to the top cover by four screws.

Cleaning

Case and keys

• Atari's own care instructions for the XE family: turn the system off before cleaning, clean only the outside with a soft, slightly damp, lint-free cloth, and do not use cleansers, abrasives or solvents.
• Keycaps can be removed and washed in mild detergent, then dried completely before refitting.

Board and connectors

• Disconnect everything before opening the case.
• Remove dust from the cartridge slot, the expansion connector and the board with a soft ESD-safe brush or clean, dry air.
• Clean oxidised contacts with isopropyl alcohol or a contact cleaner.
• Reseat socketed chips.

Connectors to inspect

Atari 130XE external connectors

Connector	Atari designation	Notes
Power	J7, 7-pin DIN (C061838)	+5 V on pins 1, 4 and 6
SIO	J1, 13-pin (C012995)	+5 V/ready on pin 10, fed through ferrite bead L10 on Atari's schematic; pin 12 not connected
Monitor	J2, 5-pin DIN (C070033)	Luminance, ground, audio, composite video, chrominance
Cartridge and expansion	J4, dual 30-pin and 14-pin (C070064)	+5 V on cartridge pin 13 and expansion pin 7
Controllers	J5 and J6, 9-pin D (C019062)	Pin 7 +5 V, pin 8 ground
Keyboard	J8, 24-pin (C061793)	24-conductor foil cable

Check the solder joints on J7 and the power switch S1, which carry all the machine's current.

Keyboard

The 130XE has a 62-key full-stroke keyboard connected to the board by a 24-conductor foil cable. Handle the cable by its stiffened end and do not fold it.

• Clean and reseat the keyboard connector before suspecting POKEY. Sams gives one erratic key as "clean the key" and a dead group of keys as POKEY U22.
• The keyboard matrix is drawn in the manual reproduction as figure 2-15, with the lines numbered by pin of connector J8; use it to tell whether a fault is one key, one row or one column.
• The self test's keyboard screen shows which keys are responding.

Video output

• The monitor socket gives composite video, separate luminance and chrominance, and audio, and does not go through the RF modulator. If the RF picture is poor, try the monitor socket.
• The reproduction specifies the modulator's output as 1–2 mV into 75 Ω, on channel 3 at 61.25 MHz ±0.5 MHz or channel 2 at 55.25 MHz, with a 5.5 MHz sound carrier. 5.5 MHz is the PAL sound spacing; for NTSC channels 2 and 3 Atari's 800XL manual gives 4.5 MHz.
• The modulator (A1, Atari C070000) is a sealed can listed as a single part; the two board capacitors feeding it, C204 and C205, are 0.1 µF ceramics.
• If colour is wrong or absent, adjust it before diagnosing: see below.

Colour adjustment

The colour control is R38, a 500 kΩ preset (Atari C023030-04). Atari's production test instructions say it can be reached through a hole in the bottom of the housing, and set it with the production test cartridge's video test: adjust until the smaller bar inside the colour tuning bar disappears. Sams' method, without the cartridge, is to switch on and adjust R38 for a blue screen on the monitor.

Periodic checks

1. Measure the power supply before connecting it, particularly after storage.
2. Run the self test: with no cartridge and no powered disk drive, hold OPTION while switching on (or type BYE at the BASIC prompt), run MEMORY, AUDIO VISUAL and KEYBOARD, and exit with SYSTEM RESET. The self test does not go into attract mode, so do not leave a test screen on a CRT for long.
3. Inspect the electrolytics. There are eleven on the board; see Atari 130XE Capacitor Replacement Guide. Look for bulging, weeping and discoloured board around C1, C2 and C3 near the power switch.
4. Reseat socketed chips and clean the cartridge slot.
5. Wait at least ten seconds between switching off and on again, and switch off before inserting or removing a cartridge, as Atari's instructions say.
6. Store the machine somewhere dry.

Related pages

• Atari 130XE
• Atari 130XE Capacitor Replacement Guide
• Atari 130XE Troubleshooting Guide
• Atari 65XE General Maintenance
• Capacitor Failure Symptoms
• Recommended Tools