Commodore 64
ASSY 326298 — First-generation breadbin, 5-pin video
Summary
The 326298 is the original 1982 C64 mainboard and the only revision with a 5-pin video connector. It carries fourteen 10 uF decoupling cans plus four larger power-supply filters - the highest electrolytic count of any C64 board.
Safety & Warnings
Test the power supply first
A recap will not protect the machine from an original Commodore "black wedge" or beige brick. These fail with the 5 V rail drifting high and take out RAM, the CIAs, the PLA and the SID. Measure the 5 V rail under load before you fit a single new capacitor, and replace the brick with a modern regulated supply.
Confirm polarity against the board, not just the silkscreen
Align the negative stripe on each capacitor with the negative marking on the PCB. Commodore silkscreens of this era are occasionally ambiguous or reversed, so if a marking looks wrong, buzz the pad out to the ground plane with a continuity tester before soldering.
Higher voltage ratings are always safe
You can fit a higher voltage rating than original (25 V or 35 V in place of a 16 V part) as long as the can physically fits. Never fit a lower rating. Capacitance should stay at the original value.
The first C64 production runs used 50 V capacitors, most likely down to parts availability. Later runs and the later schematics specify 25 V. Either is correct; the values below follow the later schematics.
This is the only C64 revision that uses C64 as a designator as well as C65 - do not mistake one for the other when you are working from a photo.
Function and rail annotations are only shown on rows where the service manual or schematic confirms them. Rows without an annotation are decoupling capacitors whose exact role is not documented in the sources used here.
Is This Your Board?
- The assembly number is silkscreened on the mainboard, usually near the cartridge port. Look for "ASSY 326298".
- Decisive test: the video connector (CN5) on this board has 5 pins. Every later C64 revision uses an 8-pin video connector.
- Eight 4164 DRAM chips in a row, and the board is the full-length "long board" that fills the breadbin case.
- This revision is often called the "silver label" board because it fits the earliest machines, though the label alone is not proof - check the silkscreen.
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
| Ref | Value | Voltage | Type | Notes | Confidence |
|---|---|---|---|---|---|
C8 |
10 uF | 25 V | Radial | Verified | |
C12 |
10 uF | 25 V | Radial | Verified | |
C13 |
10 uF | 25 V | Radial | Verified | |
C14 |
10 uF | 25 V | Radial | Verified | |
C15 |
10 uF | 25 V | Radial | Verified | |
C17 |
10 uF | 25 V | Radial | Verified | |
C19 |
2200 uF | 16 V | Axial | Largest can on the board. | Verified |
C24 |
10 uF | 25 V | Radial | Verified | |
C34 |
10 uF | 25 V | Radial | Verified | |
C57 |
10 uF | 25 V | Radial | Verified | |
C62 |
10 uF | 25 V | Radial | Verified | |
C64 |
10 uF | 25 V | Radial | Present on this revision only. Later long boards drop C64 and keep C65. | Verified |
C65 |
10 uF | 25 V | Radial | Verified | |
C88 |
470 uF | 25 V | Axial | Stays at 470 uF on this revision. The 1000 uF part belongs to later boards. | Verified |
C90 |
470 uF | 25 V | Axial | Verified | |
C91 |
100 uF | 16 V | Radial | Verified | |
C94 |
10 uF | 25 V | Radial | Verified | |
C102 |
10 uF | 25 V | Radial | Verified |
Extra Parts (not failure items)
These are not electrolytic recap candidates. They are listed because the kit vendors include them for a known modification or fix — do not replace them as part of a routine recap.
| Ref | Value | Voltage | Type | Purpose | Notes |
|---|---|---|---|---|---|
C38 |
4.7 nF | - | Ceramic | RESTORE key fix | Not an electrolytic and not a failure item. Replacing the original 51 pF with 4.7 nF restores the soft-touch RESTORE key function. Both cap-kit vendors include this part for exactly that reason. |
Mainboard — shopping list
- 14 x 10 uF 25 V Radial
- 1 x 2200 uF 16 V Axial
- 2 x 470 uF 25 V Axial
- 1 x 100 uF 16 V Radial
Recap Tips
- Work one capacitor at a time and keep the old part next to its pad until the new one is in - it is the cheapest insurance against a polarity mix-up.
- Use 105 C low-ESR parts. Panasonic FR or FC and Nichicon PW or HE series are the usual bench choices and keep ripple off the video and audio outputs.
- Boards this old often have brittle solder around the RF modulator and the power connector. Reflow those joints while you are in there.
- Keep the iron at 320-340 C and do not dwell - the single-sided laminate on early Commodore boards lifts pads easily.
Related Symptoms
- Black screen / no video Work the power rail tests first; a capacitor is rarely the cause of a hard no-boot.
- Garbage video / character corruption Usually DRAM or the PLA on a long board rather than a capacitor.
Sources & References
- Console5 TechWiki - Commodore 64 Per-assembly capacitor lists compiled from real boards and later schematics.
- Retro Rewind - C64 Assembly 326298 Cap List Independent list that agrees with Console5 on every row used here.
- Commodore 64 Service Manual (PDF) Primary reference for the official parts lists.