Howard's "Mappy" Page

I'm having some problems. The monitor image starts out screwed up when the machine is turned on, and "heals" as it warms up, but not completely. Here's an initial image, with the alignment grid:

My Mappy monitor at power-up (cold)



After it warms up, it looks like this (scrolled a bit to make it easier to see):

My Mappy monitor (warm)

Here are the technical details: WG K7000 monitor, bought refurbed from WG. It had this problem from the beginning, but I couldn't bear to send it back. Anyway, I installed a cap kit. No change. The situation hasn't changed in the years since, so I figure whatever it is, is stable.

Capkit was likely the following:

Mazzco Kit
Wells Gardner K7000 Series Monitor

C10     33u     25V
C11     22u     25V
C12     1u      50V
C13     22u     25V
C18     1u      50V
C20     10u     50V
C21     10u     50V
C22     1u      50V
C23     47u     25V
C40     2200u   35V
C42     1000u   16V
C45     470u    16V
C46     470u    16V
C48     100u    35V
C50     1000u   25V
C56     22u     160V
C57     47u     200V

Update: I've been told that this is an instance of Horizontal Tear, and I should check/replace C29, C30, C31, and R70. Thanks to Wacko172 for that.

Further update: I've finally replaced C29, C30, and C31 with no change. Haven't gotten to R70. Here's a close-up of the board, with these three caps circled.

Close-up of the monitor chasis board with C29-C31 circled Straight-down shot at the same board

Most recently, two people suggested replacing C51. I've got to find a decent supplier for this. "Decent supplier" means one who doesn't charge several times the cost of the device for shipping.

Likely final update: I've given up on this monitor. It's been sitting on my workbench for 2 years, being chewed on by my cats. I don't know if the tube still holds vacuum. At this point, I'm looking for a real video repair place to evaluate it and fix it or dispose of it.


Oh, by the way, here are the switch settings for Mappy. I did that up a while ago to answer a question in RGVAC and it would be a shame to lose it.

Also, to answer any likely questions, the machine is located in Massachusetts, it's not for sale, and I'm told this cabinet, though not the monitor or PCBs, which I added to the cabinet, started life in Massachusetts' Walpole State prison. I'd like to hear from the person who placed this particular game at a prison. I find the idea twisted, but amusing. (smile)

Last modified 23 March 2009