Atari 65XE Capacitor Replacement Guide

Replacing the original electrolytic capacitors (“recapping”) in your Atari 65XE is essential for long-term reliability and performance. Ageing capacitors can cause power instability, video artefacts, audio noise, or even prevent the machine from starting. Proactively replacing these components helps ensure stable operation, protects delicate custom chips, and cures many “mystery” faults common in vintage Atari 8-bit systems.

Visual Inspection & Failure Signs

Before starting, carefully examine all electrolytic capacitors on the mainboard for:

• Bulging or domed tops – Indicates internal gas pressure and imminent failure.
• Leaking electrolyte – Brown, green, or white crust around the base or legs.
• Corroded or stained PCB areas – Suggests past leakage, especially near the power input.
• Random resets, video glitches, or audio hum – Often traceable to dried-out or high-ESR capacitors.

If any capacitor shows signs of failure, it is strongly recommended to replace all electrolytic capacitors on the board.

Atari 65XE Capacitor List

The 65XE mainboard uses a mix of through-hole and, in later revisions, some SMD electrolytic capacitors. Always cross-check your board’s silkscreen and reference numbers, as minor layout changes exist between European and US models.

Mainboard Electrolytic Capacitors

Atari 65XE Mainboard Electrolytic Capacitors

Ref. Designator	Capacitance	Voltage	Function / Location
C1	2200 µF	16 V	Main +5 V input filter (power smoothing)
C13	470 µF	16 V	+5 V local decoupling (CPU/ASIC area)
C41	100 µF	16 V	Video circuit decoupling
C42	10 µF	16 V	Audio output coupling
C43	10 µF	16 V	Audio input coupling (monitor port)
C44	1 µF	50 V	Video chroma coupling (monitor port)
C45	10 µF	16 V	Reset circuit timing
C46	10 µF	16 V	SIO circuit decoupling
C47	10 µF	16 V	SIO circuit decoupling
C48	10 µF	16 V	SIO circuit decoupling
C49	10 µF	16 V	SIO circuit decoupling
C50	10 µF	16 V	SIO circuit decoupling
C51	10 µF	16 V	SIO circuit decoupling
C52	10 µF	16 V	SIO circuit decoupling
C53	10 µF	16 V	SIO circuit decoupling
C54	10 µF	16 V	SIO circuit decoupling
C55	10 µF	16 V	SIO circuit decoupling
C56	10 µF	16 V	SIO circuit decoupling
C57	10 µF	16 V	SIO circuit decoupling
C58	10 µF	16 V	SIO circuit decoupling
C59	10 µF	16 V	SIO circuit decoupling
C60	10 µF	16 V	SIO circuit decoupling
C61	10 µF	16 V	SIO circuit decoupling
C62	10 µF	16 V	SIO circuit decoupling
C63	10 µF	16 V	SIO circuit decoupling
C64	10 µF	16 V	SIO circuit decoupling
C65	10 µF	16 V	SIO circuit decoupling

Note: Some later 65XE boards (especially “Cost Reduced” versions) may use SMD electrolytic capacitors for some of the 10 µF positions. Replace with equivalent SMD or use carefully-fitted radial types.

Power Supply (External)

The 65XE uses an external 5 V DC power supply (“brick”). If you experience unstable voltages or excessive ripple, inspect and recap the PSU as well. Typical values:

Atari 65XE Power Supply Capacitors (typical)

Capacitance	Voltage	Notes
2200 µF	16 V or 25 V	Main filter (inside PSU brick)

Always open and service the PSU only if you are experienced with mains voltages.

Capacitor Replacement Procedure

1. Disassemble: Remove the case screws (usually five underneath), then gently lift the top case. Disconnect the keyboard flex cable.
2. Remove the mainboard: Unscrew and lift out the PCB, noting the orientation of all connectors.
3. Desolder old capacitors: Use solder wick and/or a pump. Take care not to lift pads, especially on single-sided boards.
4. Clean pads: Remove old flux and any leaked electrolyte using isopropyl alcohol.
5. Install new capacitors: Observe polarity (long lead = positive; silkscreen usually marks negative). Use low-ESR, 105 °C rated parts.
6. Trim leads and solder: Ensure solid, shiny joints. Avoid excess solder.
7. Inspect: Check for solder bridges and correct orientation.
8. Reassemble and reconnect: Fit the board, connect the keyboard, and close the case.

Recommended Tools & Parts

• Temperature-controlled soldering iron (15–40 W, fine tip)
• Desoldering pump and/or braid
• Isopropyl alcohol (IPA) and small brush
• Lead-free or leaded 0.5–0.7 mm solder
• ESR meter (optional, for testing old capacitors)
• Quality 105 °C, low-ESR capacitors (e.g., Nichicon, Panasonic, Rubycon)
• Tweezers (for SMD parts, if present)
• Antistatic wrist strap

Post-Recap Voltage & Ripple Checks

After recapping, verify the main voltage rails with a multimeter or oscilloscope:

Expected Voltage Rails – Atari 65XE (no cartridge)

Test Point	Nominal Value	Acceptable Range	Max Ripple (p-p)
+5 V (mainboard input)	5.00 V	4.85–5.15 V	< 50 mV
+5 V (CPU, RAM, ANTIC)	5.00 V	4.85–5.15 V	< 50 mV
Audio out (monitor port)	–	–	No hum/buzz

If you observe excessive ripple (>100 mV) or unstable voltages, recheck your soldering and consider recapping the external PSU.

Additional Tips

• Check the power brick first! A faulty PSU can damage new capacitors and chips.
• Keep capacitor height below 18 mm to ensure the metal shield fits.
• Double-check polarity before soldering – reversed caps may explode.
• Clean any leaked electrolyte thoroughly, as it corrodes PCB traces.
• Retain original lead spacing (usually 5 mm for 10–100 µF, 7.5–10 mm for 2200 µF).
• If SMD caps are present, use quality SMD replacements or carefully adapt radial types.
• Power up with a current-limited supply or fuse for first test after recapping.

Related Pages

• Atari 65XE Troubleshooting Guide
• Atari 8-bit Power Supply Maintenance
• Atari 800XL Capacitor Replacement Guide