John in NH's

Tube Swap Walkthru

Lately there has been some talk around the group about tube swapping being right up there with Voodoo and Black Magic as far as danger and mystery goes. Well, that's not the case. I've done a few now and haven't died yet - not once! :)

I took these pics when I did a recent swap in my Ms. Pac. This was about a week or so before James Sweet's nice write-up was posted. Here's his:

http://coinop.org/repair/Monitor_Tubeswap.aspx

Between my write-up here and his, almost anyone familiar with general game repair should be able to do a tube swap without dying.

Speaking of which, thou shall not sue if you're a dumbass and drop a tube, cutting your legs to shreds or losing an eye from the exploding glass. Also, thou shall not whine to me if you discharge the monitor with your tongue, etc. In other words, if you don't know what you're doing and get hurt trying this stuff, you have nobody to blame but yourself. What a novel concept. . .

Now, to the fun:

Feel the burn!

Severe Ms. PAC burn looks even worse on a Multipac when playing Crush Roller. This will never do. . .



Even worse naked

With the smoked plexi and bezel removed, you can really see how bad this tube is.



As an aside

Here's the huge screwdriver/wire/clip setup I use to discharge monitors. Discharge it prior to the next step.



Electronics removed

The HV anode, neck board, yoke molex to the chassis, etc. all removed from tube.



Coming out party

The Gator Grip (as seen on T.V.) works at getting the CRT's bolts loose.



What holds it in?

The CRT has a metal frame around the tube. On the corners of that frame are flat protrusions that rest on the monitor brackets. A bolt/screw/whatever holds the CRT in place. When loosening them, I tend to take two out completely, then loosen the other two up a bit. I then remove one of those completely and do the last one by hand while cradling the tube a bit in case it wants to slip a bit. The grounding spring and degaussing coil may also be removed prior to taking out the tube.



Out, out!

The naughty tube is removed.



Standing by

The cabinet waits for a new tube. That's the degaussing coil hangin' out.



Yoke , etc.

The yoke and convergence rings. You'll need them later. Mark their relative positions with white-out (not shown) so you can line up the rings if they get shifted during removal. The rings, and sometimes the yoke, are held in place with a screw/clamp combo. The yoke may just have a thumbscrew. Sometimes, they also have dried hot glue. Carefully pick it off prior to trying to remove them.



Old tube

The original pic tube was an RCA. . .



New tube

. . .and the new one is a Hitachi. It doesn't really matter what brand, provided the end of the neck, where the neckboard attaches, is laid out the same.



SCIENCE!

Place the new tube in the game. I keep one bolt in my teeth while I do this so it's within easy reach. Install that one bolt as tight as possible with your fingers then install and tighten them all properly with tools. Be sure to reloop the grounding spring and degaussing coil around the CRT prior to bolting it in. Now, before I apply the power, I cover the game in a thick blanket. This is probably very unnecessary but in case the CRT blows up for some unknown reason, it will minimize the damage. :)

In this pic, the yoke needs a twist and other fiddling and I need to fiddle a bit with the color convergence rings. NOTE: This is the biggest pain of the whole job. :P



After an hour of fiddling with the yoke, etc.