Wells Gardner 19K4605 -=UPDATE=-

[twobad]

I purchased my first arcade machine which I plan to convert to MAME.  It is a 1980 Game Plan "Megatack" with a Wells Gardner 19K4605 sn 048942 and date of manufacture July 1981.  It has video issues as seen the the attached picture.  If necessary I plan a cap kit but I have suspicion that it might be video RAM associated and when I  hook up the computer it might no longer be an issue.  Your thoughts are appreciated.  WG's website does not acknowledge this model and Bob Roberts' lists only a cap kit for a 4600 model (mine is a 4605)- is this the correct kit for my monitor.

The picture was drastically resized to meet forum posting requirements.  The things to note are the columns of red dots that should not be there and the missing columns in the green and yellow at the bottom (and in the text at the top.)  The general "fuzziness" of the picture is due to shrinking the .jpg photo.

This site rocks!

Sincere thanks,
-=T=-

[mgb]

Not saying that it will fix all your issues, but definitely do a full cap kit on the board.
the 4600 kit from bob roberts, I believe comes also with a pot that typically needs replacement on one of the daughter boards.
also with that monitor, there are 2 daughter boards. resolder the back side of those connectors where the boards plug into, they often get cold joints.
Thats a pretty old monitor so reflowing a good amount of solder joints will clear alot of issues.

from your pic, it alomost looks like the convergance rings on the rear of the tube may need adjustment but you'd be best off to not touch them. try all the other regular repairs and see how it goes.

[twobad]

Thank you so very much,
-=T=-

[mgb]

No problem.
Remeber if you have never worked on a monitor before, be sure to look up info about monitor safety and how to safely discharge the monitor before removing the boards.

[twobad]

Ahhh, yes- I've read and seen in person why that is of utmost importance

[twobad]

OK, did the cap kit.  Got pics this morning, noted red vertical lines were not there.  Managed to snap one pic then I saw the lines were back.  Still suspect video ram board issues (know I have sound issues).  Can you tell any improvement between before and after pics?  I plan to go MAME and don't really want to spend a bunch of time on the dedicated boards, really just want to know if it's time to order that special video card that does the 15Khz thing, but don't want to blow the dough if the monitor is not good...
Thanks again,
-=T=-

The first pic is right after plugging in, the others are less than a minute or two later (the filenames are timestamps...)

The pic in my first post was megapixel, shrunk for this forum, the other four are native 480 x 640...

[lilshawn]

i can tell you with certainty that you have a ROM or SRAM issue.

make sure all the chips are firmly pushed down.

[mgb]

Yes I agree, looks like issues withe chips on the game board. I imagine that won't matter if you're gonna pull the game board anyway. If you are interested in clearing it to verify, I have always had great results pulling socketed chips and cleaning the legs very carefully with a wire wheel on a dremell tool. I say again, very carfully and be prepared to possibly repair broken chip legs.
I also assume that you did resolder the header connectors for the daughter boards on the monitor.
And verify that the 5 volts is adjusted correctly at the game board. I usually meter it at the power pins of a chip and make sure to adjust it to 5.2 volts or at least do this while metering where the power hits the board.

[twobad]

I re-soldered ONE of the header pins on the chassis where the daughter boards plug in and it angled away from being straight.  I heated the pad again and got it more or less back inline- getting a bit scared of "over heating" at this point   I thought the odds were that if I re-soldered them all they would be severely out of alignment and I'd do more harm than good.  I also thought that I should NOT re-flow the joints with the daughter boards in place as they might get permanently attached, causing yet another problem. So...

how does one keep "header pins" parallel when soldering?

Thanks,
-=T=-

[lilshawn]

if you can, find a scrap connector that fits the pin spacing, I just plug them on to hold them in place and keep them from shifting.

short of that, I've used a few pieces of metal bracketing and a clamp to hold them steady.

[twobad]

I resoldered the header pins for the two daughterboards and have the ArcadeVGA card and ipac2 module sending MAME to my cabinet with WG4605 monitor.  (cap kit was also completed...) 
The screen looks very "WEAK" and has color bleed (i.e.- each dot in the ms pacman maze is in triplicate with red being diagonally lower left, white/yellow in the middle and blue diagonally upper right.  I'm aware of the "brightness" pot on the  daughterboard and the red, green and blue pots on the neck of the tube.  In addition there are a couple of white pots to the side of the neck and a pot on the flyback.

Is there a MAME "test pattern" rom that can be put on the monitor for adjustment or a game ROM with a static image good for making golor and focus adjustments.  The pause feature freezes any game but makes the picture EVEN WORSE...

Thanks guys,
-=T=-

[lilshawn]

you, dear sir, have a yoke problem.

it's been knocked out of alignment.

[twobad]

having taken the chassis out twice, once for cap kit and once for daughterboard pins, wouldn't surprise me- it there a sticky or video available for learning how to fix this- thanks again (as always) lilshawn...
-=T=-

[twobad]

please tell me it's on par or less difficult than a cap kit- I have two of those under my belt in the last month ...

and I guess i take it I should leave the convergence rings the heck alone???

also, I don't remember being overly aggressive or bumping anything REALLY hard although I did get a bit cocky removing the chassis and had two ground wires tugging back at me that I had to release before I could get the chassis removed to do the daughter pins...

One more note, after removing the "bezel plexiglass" and cleaning it and the face of the screen of 31 years of dust, the "dimness" issues that plagued me have been greatly diminished.

Please tell me it's not fubar...
TIA,
-=T=-

[mgb]

I could be wrong, but to me it looks like its just out of focus.
I had jobs where I had to mess with the convergance rings and you can see the seperation of the colors.
In these pics it just looks blurry

[twobad]

i REALLY have been turning the pots and started with what the arcaderepairtips.com guys call the "focus"- this chassis has a pot on the flyback that appears to do little and one of two daughterboards that has a pot that does a LOT in terms of "brightness"

any WG 4905/4906 (??)  experts out there?
-=T+-

[mgb]

well taking a second look at the close up of the maze, it does appear that you can see the seperation there.

messing with the convergance rings is not a hole lotta fun.I try not to mess with them if I don't have to.

I would say your best bet is to first try and mark the rings placement and then very slowly start messing with the rings one at a time while someone is watching the monitor and telling you if its getting better or worse.
sometimes you will see some old glue on the rings and that may give you an idea of how to turn. Its definitely alot of trial and error though.
turn it one way and then back and try the next ring and so on and so forth.

I had to go through this once with a customers Donkey Kong. you could see the scor numbers at the op of the screen looked like each digit was 3 layers not quite aligned over each other. I very slowly tweaked the rings while the customer told me how it was going. It sucked but the monitor still looks perfect 2 years later.

Any chance of you having a tv repairman or someone like that around.
maybe someone here on the forums is around your area. where are you located?

[lilshawn]

http://www.wellsgardner.com/pdf/Service/K7000.pdf

start at page 5

[twobad]

thanks guys...