Commodore 64
ASSY 250466 — Late breadbin "long board"
Summary
The 250466 is the final breadbin board and the transitional revision: two 41464 DRAM chips in place of the earlier eight 4164s. Its capacitor list matches the 250425 with one addition - the 2.2 uF at C200.
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. 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.
This board uses the same six power and decoupling electrolytics as the 250425, plus C200. If you are working from a 250425 list, C200 is the one you will miss.
Function and rail annotations are only shown on rows where the service manual or schematic confirms them.
Is This Your Board?
- The assembly number is silkscreened on the mainboard, usually near the cartridge port. Look for "ASSY 250466".
- Decisive test: two DRAM chips (41464) instead of eight. It is still a full-length long board in a breadbin case, so the RAM count is what separates it from a 250469 short board.
- The 250466 has a 2.2 uF electrolytic at C200. The otherwise identical 250425 does not.
- Silkscreen version marking is usually B-3.
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 |
|---|---|---|---|---|---|
C13 |
10 uF | 25 V | Radial | Verified | |
C19 |
2200 uF | 16 V | Axial | Largest can on the board. | Verified |
C24 |
22 uF | 25 V | Radial | Verified | |
C88 |
1000 uF | 25 V | Axial | Verified | |
C90 |
470 uF | 25 V | Axial | Verified | |
C91 |
100 uF | 16 V | Radial | Verified | |
C200 |
2.2 uF | 50 V | Radial | Unique to this revision among the long boards. Small can near the video circuitry. | 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
- 1 x 10 uF 25 V Radial
- 1 x 2200 uF 16 V Axial
- 1 x 22 uF 25 V Radial
- 1 x 1000 uF 25 V Axial
- 1 x 470 uF 25 V Axial
- 1 x 100 uF 16 V Radial
- 1 x 2.2 uF 50 V Radial
Recap Tips
- Seven capacitors, all easy access. Still check the power supply before you start.
- Use 105 C low-ESR parts. Panasonic FR or FC and Nichicon PW or HE series are the usual bench choices.
- Check can diameter before ordering - the 2200 uF axial at C19 and the 1000 uF at C88 have to clear the RF shield and the case.
- If you have already removed the RF modulator for a composite or S-video mod, C200 is much easier to reach.
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 On this board suspect the two 41464 DRAM chips or the PLA before the capacitors.
Sources & References
- Console5 TechWiki - Commodore 64 Per-assembly capacitor lists compiled from real boards and later schematics.
- Retro Rewind - C64 Assembly 250466 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.