Installing A Cap Kit

Installing a cap kit on your monitor chassis can be a great way to restore washed out colors as well as fix other problems that you might encounter. In this post, we will take a look at how to identify what cap kit you need and how to install it once you have received it.

Installing A Cap Kit

Here’s another video from our friend Dan that also shows you how to install a cap kit. Thanks Dan for letting us use it!

Cap Kit (Dan’s YouTube Channel)

Before you can install a cap kit you need to identify what cap kit you need. If you know the brand and model of your arcade monitor then getting the correct cap kit is easy. If you do not, however, then your first step is to find out. Look on the monitor frame or tube for any stickers that might indicate a brand and/or model. If you do not see any stickers or still can’t identify it, take out the chassis (please review how to Safely Discharge A Monitor) and compare it to the images on the What’s My Monitor? page on therealbobroberts.net. Bob Roberts is also a great source for cap kits if you need to purchase one.

Once you have identified, ordered, and received your cap kit, it’s time to get started with the installation. Before you start installing your cap kit, we recommend reviewing our post on Your First Arcade Toolbox as it goes over exactly what tools you will need to perform this procedure.

Now, let’s talk about some general information about electrolytic capacitors or caps. Most of the caps that you will receive in your cap kit will have two numbers printed on them. The first number is usually the voltage indicated by the letter v after it. The second number is usually the microfarad indicated by symbol μf after it. Caps also have polarity meaning that there is a positive and negative end. The negative end is usually indicated by the shorter lead and the positive the longer lead. There is also a stripe on the cap itself that will usually indicate the negative lead.

It is important to note that you must replace a cap with another cap of the exact same microfarad and in the exact same polarity position. Should you use a cap with the wrong microfarad or place it in the wrong polarity position your monitor will end up in worse shape than when you started. Another important note is that the voltage of the new cap does not have to match the voltage of the old cap. As long as the voltage is greater than or equal to the original cap you should be fine.

With all of that said, let’s replace our first cap. The first thing you want to do is locate a cap that you want to replace. A bad electrolytic capacitor will often swell or bulge at the top or leak out of the bottom, however, they can still be bad even if they don’t look bad. If you have an ESR (Equivalent Series Resistance) meter you can test the cap before you remove it to see if it’s bad or not. Since caps are so cheap, however, it’s good to just go ahead and replace them all. Use either a desoldering iron or solder wick to remove the solder from around the leads of the original cap. Be careful not to pull up or damage the trace on the board as this can cause problems. Once that is done, remove the cap making sure that you note the polarity position of the negative and the positive leads.

Look through your cap kit and locate a cap that has the same microfarad and the same or greater voltage as the original cap. Put the new cap in the same place and polarity position as the original cap. Pull the leads up through the holes and bend them away from each other so that the cap stays in place. Solder the leads to the board using your soldering iron and some solder. Once the solder cools, clip the protruding part of the leads from the board using some wire cutters and you’re done with one cap. Continue repeating this process until you have used all the caps in your cap kit.

While applying a cap kit to a monitor will not fix every monitor problem, it can help with issues such as washed out colors, vertical drop, and/or lines across the top of the screen. Now you can fix these common issues yourself without too much trouble. Do you have any other comments or suggestions about installing a cap kit? Please leave them below in our comments section.