Amiga 1200
Rev 1D.4 / Rev 2B (AGA) — 32-bit AGA wedge mainboard
Complete Diagnostic Flowchart: Amiga 500/600/1200 Boot Color Code, Chip RAM & Audio/Video Isolation (Commodore Amiga 500 (Rev 3/5/6A) / A600 / A1200)
Summary
Every factory Amiga 1200 carries 12 surface-mount electrolytic capacitors that leak corrosive electrolyte onto the 24-bit Lisa/CXA1145 video section, Paula audio outputs, and PCMCIA/reset traces, plus 5 through-hole radial bulk capacitors.
Interactive Bench Oscilloscope — Verify Pre- & Post-Recap Waveforms
Open Full Signal Visualizer →Click any test point below to compare a healthy recapped rail or clock against high-ESR electrolytic capacitor ripple and droop:
Safety & Warnings
Check C237 & C407 polarity on early silkscreens
Photograph the original capacitor stripe orientation before removal; always match the original factory capacitor orientation rather than relying solely on ambiguous perimeter brackets.
Shield the keyboard MPU and IDE/Floppy headers
Use Kapton tape and aluminum foil tape over the 44-pin IDE header and keyboard connector when using hot air.
On Rev 1D.4 and Rev 2B boards, also inspect E123C and E125C on the bottom of the PCB if fitting an 030/040/060 trapdoor accelerator.
Is This Your Board?
- Look between the floppy power header and the ROM sockets for "A1200 REV 1D.4" or "REV 2B".
- Count 12 silver SMD cans across the upper-left video/audio/RF zone and 5 radial through-hole cans near the power input and floppy connector.
Verified rows are agreed by two or more independent sources. Check rows are revision-dependent or single-sourced — confirm the value against your own board before ordering.
Mainboard (A1200 Rev 1D.4 / 2B)
| Ref | Value | Voltage | Type | Function | Notes | Confidence |
|---|---|---|---|---|---|---|
C214 |
10 uF | 35 V | SMD (B) | CXA1145 RGB/Video encoder | Verified | |
C235 |
47 uF | 16 V | SMD (C) | Video luma filter | Verified | |
C236 |
47 uF | 16 V | SMD (C) | Video coupling | Verified | |
C237 |
10 uF | 35 V | SMD (B) | Chroma sub-carrier | Verified | |
C239 |
47 uF | 16 V | SMD (C) | Composite video output | Verified | |
C303 |
22 uF | 35 V | SMD (D) | LF347 op-amp rail | Verified | |
C304 |
22 uF | 35 V | SMD (D) | LF347 op-amp rail | Verified | |
C305 |
10 uF | 35 V | SMD (B) | Audio bias reference | Verified | |
C306 |
100 uF | 16 V | Radial | Audio Vref decoupling | Verified | |
C307 |
470 uF | 16 V | Radial | +5V audio/floppy bulk | Verified | |
C324 |
22 uF | 35 V | SMD (D) | Left audio RCA out | Verified | |
C334 |
22 uF | 35 V | SMD (D) | Right audio RCA out | Verified | |
C407 |
10 uF | 35 V | SMD (B) | Lisa / DAC reference | Verified | |
C409 |
100 uF | 6.3 V | SMD (C) | Video DAC decoupling | Verified | |
C811 |
100 uF | 25 V | Radial | +12V DC input filter | Verified | |
C821 |
1000 uF | 10 V | Radial | +5V main reservoir | Verified | |
C822 |
470 uF | 16 V | Radial | +5V secondary reservoir | Verified |
Mainboard (A1200 Rev 1D.4 / 2B) — shopping list
- 4 x 10 uF 35 V SMD (B)
- 3 x 47 uF 16 V SMD (C)
- 4 x 22 uF 35 V SMD (D)
- 1 x 100 uF 16 V Radial
- 2 x 470 uF 16 V Radial
- 1 x 100 uF 6.3 V SMD (C)
- 1 x 100 uF 25 V Radial
- 1 x 1000 uF 10 V Radial
Recap Tips
- Solid polymer SMD capacitors (22 uF, 47 uF, 100 uF) are a popular upgrade on A1200 boards because they never leak.
Related Symptoms
- Dim or Jailbar RGB / Composite Video Check C214, C235, C236, C239 and C409 around Lisa and CXA1145.
Sources & References
- Console5 TechWiki - Amiga 1200 Complete A1200 SMD and through-hole capacitor list.