Recap guide
Recap the Commodore VIC-20
Few caps, and cheap kits exist for the two main board revisions. A recap here is preventive.
Open the interactive checklist Tick off each capacitor as you replace it. It saves in your browser.
Check first. A recap is not always the answer here, so look at the guides before you order parts.
Which board do I have?
Boards changed during production. These notes come from the linked sources, and many are only partly documented, so check the board in front of you.
- VIC-20 original long board, assy 324003 (Medium confidence). How to tell: Long board that fills the case width. Capacitors: Pack contents: 2x 1uF radial, 2x 10uF radial, 1x 22uF radial, 2x 100uF radial, 1x 4700uF axial. Capacitor list differs from other revisions: yes. Source
- VIC-20 CR short board, assy 250403 (Medium confidence). How to tell: Short cost reduced board. Capacitors: Shared pack: 1x 1uF, 3x 10uF, 1x 47uF, 1x 100uF, 1x 2200uF axial; on 250403 only two of the 10uF are used and the 47uF is not needed. Capacitor list differs from other revisions: yes. Source
- VIC-20 CR short board, assy 251040 (Medium confidence). How to tell: Short board. Capacitors: Same shared pack; the 47uF is used only on 251040. Capacitor list differs from other revisions: yes. Source
Where to start
Clues from write-ups and forum threads, not a diagnosis. Low confidence means one thread or one repair; high means several write-ups agree.
- Kits by board (Medium confidence). One kit seller lists the exact contents of its two packs by board assembly number, which doubles as a parts list. Source
- Full recap example (Low confidence). One restoration replaced all the caps and added one more, without giving values. Source
Tips, tales and maybes
Found in write-ups and forum threads. These are other people's reports, not tested by us. Check part references and values against your own board.
- Story: Recapped but the VIC chip was the fault (Low confidence). One owner lost video on a VIC-20, replaced all the electrolytics and cleaned the board with no change, then another member diagnosed a faulty VIC chip. Single report, but a reminder not to assume caps are the cause. Source
- Tip: Transil diodes and selective replacement (Low confidence). A VIC-20 restoration replaced only the electrolytics and added two transil diodes for surge and polarity-reversal protection, which the original lacked. The author notes Commodore left some caps out to save cost. Source
Before you start
- Boards changed during production. Check your board number against the guides before you order parts.
Guides we used
This page and the interactive bench are built from these. They have the photos and the full detail, so please read them and support their authors.
- Replacement capacitors for the VIC 20 (Kit page) by Retroleum. Has a capacitor list. Shows exact contents of the two kits by board assembly number; handy as a parts list
- Ovesen.net - VIC20 repair and recap (Video) by Ovesen.net (YouTube), listed on Commodore News. News listing embedding the video
- Restoration of a Commodore VIC-20 (Write-up) by Valoroso. All caps replaced plus one added; no values given
VIC-20 board 342002 Rev E
Seven capacitors. Console5 lists the last one with no reference number.
| Part | Value | Volts | Type |
|---|---|---|---|
| C1 | 4700 µF | 16 V | check your board |
| C3 | 100 µF | 16 V | check your board |
| C7 | 47 µF | 16 V | check your board |
| C9 | 100 µF | 16 V | check your board |
| C11 | 1 µF | 16 V | check your board |
| C22 | 1 µF | 16 V | check your board |
| C? | 10 µF | 16 V | check your board |
VIC-20 assy 324003 (2 pin power connector)
Eight capacitors on the long board. The 4700 uF at C39 is the big one.
| Part | Value | Volts | Type |
|---|---|---|---|
| C13 | 1 µF | 50 V | check your board |
| C16 | 1 µF | 50 V | check your board |
| C23 | 10 µF | 16 V | check your board |
| C24 | 10 µF | 16 V | check your board |
| C25 | 22 µF | 16 V | check your board |
| C31 | 100 µF | 16 V | check your board |
| C39 | 4700 µF | 16 V | check your board |
| C44 | 100 µF | 16 V | check your board |
VIC-20 assy 250403 (DIN power connector)
Six capacitors on the short cost-reduced board.
| Part | Value | Volts | Type |
|---|---|---|---|
| C11 | 1 µF | 50 V | check your board |
| C15 | 10 µF | 16 V | check your board |
| C17 | 10 µF | 16 V | check your board |
| C33 | 100 µF | 16 V | check your board |
| C39 | 2200 µF | 16 V | check your board |
| C42 | 10 µF | 16 V | check your board |
Shopping list
21 capacitors in all, grouped by value. Buy a few spares.
- 6 x 10 µF, 16 V (check your board): Amazon · eBay
- 5 x 100 µF, 16 V (check your board): Amazon · eBay
- 3 x 1 µF, 50 V (check your board): Amazon · eBay
- 2 x 1 µF, 16 V (check your board): Amazon · eBay
- 2 x 4700 µF, 16 V (check your board): Amazon · eBay
- 1 x 22 µF, 16 V (check your board): Amazon · eBay
- 1 x 47 µF, 16 V (check your board): Amazon · eBay
- 1 x 2200 µF, 16 V (check your board): Amazon · eBay
Console5 capacitor kits for this machine
Console5 sells ready-made capacitor kits. Kits come in different versions, so match the board number in the kit name to yours and check the listing before you buy.
- Commodore Vic 20 Computer Cap Kit 2 Pin Power Connector Assy 324003
- Commodore Vic 20 Computer Cap Kit Circular Power Connector Assy 250403
Skip the sourcing
While you are in there
Affiliate links. As an Amazon Associate I earn from qualifying purchases. These links only search by name. Disclosure
Step by step
- Photograph both sides of the board before you touch anything. Zoom in on every capacitor. The photo is your map when you are three hours in.
- Unplug it, take out the batteries and let it sit. Old power supplies and CRT parts can hold a charge. If your machine has a tube, leave the tube and its board to a professional.
- Open it up and keep the screws sorted. A muffin tin or an egg carton works. Different screws go in different holes, and the holes never forgive you.
- Look for leaks. Clean any sticky residue off with isopropyl alcohol and a soft brush. A leaked capacitor leaves brown crust and can eat copper traces. Look at the traces under it, not only the part itself.
- Mark the polarity of every capacitor on the photo before it comes off. On an electrolytic, the stripe marks the negative leg. The board usually shows a half-shaded circle or a bar for the same spot.
- Remove the old capacitors one at a time. Surface mount: add fresh solder to both ends and rock the part off, or use flux and a low-melt alloy. Through-hole: heat one leg at a time and clear the hole with wick or a pump.
- Clean the pads and check for lifted pads or damaged traces. Clean flux off with isopropyl. A bad pad needs a jumper wire, not hope.
- Fit and solder the new capacitor, matching polarity. Same capacity, same or higher voltage, and it has to physically fit. Work from the smallest parts up.
- Clean the flux off and look at every joint. A good joint is shiny and shaped like a tiny volcano. A dull blob or a ball is a cold joint: reflow it.
- With a multimeter, check for shorts across the power rails before you power it on. Use the continuity or resistance setting. A reading near zero means stop and look for a solder bridge.
- Power it up and test everything: video, sound, controls, the lot. If something is wrong, check polarity first. It is the most common mistake and the easiest fix.
Tools
- Temperature-controlled soldering station. Steady heat so you do not cook pads. Most recaps are done between 320 and 350 C. Top: Hakko FX-951 · Mid: Hakko FX-888D · Budget: Pinecil
- Good solder. Rosin-core 63/37 flows and looks right. It is cheap and it matters. Kester 44 63/37
- Flux. Flux is what makes old joints let go and new joints flow. MG Chemicals flux pen · Chip Quik flux syringe
- Low-melt alloy (for surface mount). Melts old solder on both ends of a surface mount part at once, so it lifts off cleanly. Chip Quik SMD1
- Desoldering tool. Clears the old solder out of through-hole pads. Top: Hakko FR-301 · Mid: Engineer SS-02 pump · Budget: Solder wick
- Fine tweezers. For holding small surface mount parts exactly where you want them. ESD-safe tweezers
- Board holder. A third hand for the board, so both of yours are free. PanaVise circuit board holder
- Magnification. You cannot fix what you cannot see. Surface mount parts are tiny. Top: Stereo microscope · Mid: Head visor · Budget: Lighted magnifier
- Multimeter. Continuity, shorts and rail voltages. The one test that saves boards. Top: Fluke 117 · Mid: Fluke 101 · Budget: AstroAI
- ESR and capacitor tester. Checks old capacitors and your new ones before they go in. Top: Peak Atlas ESR70 · Budget: LCR-T7
- Isopropyl alcohol (99%) and a brush. For cleaning leaked goo and flux. Use the high-percentage kind. MG Chemicals 99.9% isopropyl
- Brass tip cleaner. A clean tip transfers heat. A dirty one does not. Hakko 599B
- Fume extractor. Pulls the smoke away from your face. Hakko FA-400 · Budget: Small bench fan
- Precision screwdrivers. Most old gear uses a mix of Phillips, Torx and security bits. iFixit Pro Tech Toolkit
- Kapton tape. Heat-proof tape to protect parts that sit close to the one you are changing. Kapton tape
Safety
- Good airflow, or a fume fan. Solder smoke is not for breathing.
- Safety glasses on. Solder spits and clipped legs fly.
- Iron in its stand when you are not holding it. Know where the cord is.
- Touch bare metal first, or use a wrist strap. Static kills old chips.
- No tube, no mains power supply. Leave those to a professional.
- Wash your hands after, especially if you used leaded solder.
Values are shown as published in the guides above, and boards changed during production. Check the board in front of you. A recap involves hot tools and, on some machines, dangerous voltages. You do it at your own risk.