Mrs. Pacman help

[lordkahless214]

well you can get leg levelers from pretty much any arcade parts dealer, but for standard ones I get them here:

http://www.twistedquarter.com/index.php?main_page=index&cPath=219_220

 I have also looked into leg levelers with teflon from arcade, but those are more expensive (and come only in a bag of 24 IIRC)

[P-feif]

Looks like they've got a good selection I'll look into it more. Thanks!

[P-feif]

Thanks lordkahless214 I orders a set from them.


On to the next thing. I just got done installing the cap kit from Bob Roberts on my WG 4900 monitor. I noticed I had an extra cap and could not find the location on the board. The sheet with the kit said the location was C366. Eventually I did find that location but there is no cap installed there. It was left blank from the factory. There is a diode at that location that the non banded side is soldered to the + hole that he cap would go to, and then the diode skips over the - hole and goes to a third hole on the board. So do I install this cap at C366 or leave it out?

Also I discovered why I was having such a hard time understanding the Wells Gardner schematic for the 19" monitor that is in the Mrs. Pacman manual. The Mrs. Pacman manual has a schematic for a WG 4600 monitor. My Mrs. Pacman came with a WG 4900 installed. After digging around the Mrs. Pacman manual I could find no mention of a WG 4900 so either Midway never put the WG 4900 schematic in the manual or Mrs. Pacman never came with a WG 4900 and someone swapped in a WG 4900 at some point. Well it's what I've got to work with so I'm sticking with it especially since I have the entire cap kit installed now and just a few resistors and color transistors yet to install. Opinions??

Also one of the caps that I replaced, I had a real bad time getting the old one out. For some reason the legs were stuck and would not come out of the board. At some point the cap just fell off and the legs were still in the board. When I looked at it I found that someone had cut off a cap and soldered a new one to the legs that were still there. I considered this a very hokey repair. So I kept working at it and eventually got the old legs out. One of the solder pads was half missing. I'm pretty sure there was an issue there and someone just hacked it together. I installed the new cap and soldered it the best that I could to the half pad, and then bent the leg over to the next solder point along that trace and soldered it to that point. Let's see how that works.

[iankellogg]

i'll have to look at it for C366, i really can't remember the with that.

As far as ms pac goes, I dont believe they ever came in a K4900 so I would consider yourself lucky as the K4900 is one of the best monitors you can get.

[lordkahless214]

I remember when I did the 4900 in my Q*bert that one cap was with a diode in the same holes like you are describing so I  kept it like that, but I don't remember which cap it was on.

I will be doing more work on that cab on Wednesday, so I can look when I pull it out from the wall if you haven't found an answer by then.

[P-feif]

I remember when I did the 4900 in my Q*bert that one cap was with a diode in the same holes like you are describing so I  kept it like that, but I don't remember which cap it was on.

I will be doing more work on that cab on Wednesday, so I can look when I pull it out from the wall if you haven't found an answer by then.

The one you're talking about is at C373, and yes I did change that one. Per the Bob Roberts sheet that came with the cap kit... "*This cap is across D306 in some versions with the - side going to the banded side of D306." Yes I changed this one.

As for the cap at C366 the sheet doesn't say what to do with it. It is in the same location as a diode at D307 sharing only the positive leg. The negative leg for the cap is blank on my board with nothing in it. There is currently a diode in that location. The negative leg of the diode stretches across the cap location and goes to another hole in the board all together and does not share the negative hole with the cap.

Thanks for any help you guys can give. So far my searches on the internet for an answer to this have not gotten me anywhere.

[lordkahless214]

Ok so it was C373 it's been a long enough time I couldn't remember which one it was.

well I figured there was one thing I could do to help you out here, I called up my arcade op friend who is very familiar with this particular model and asked him about your issue, he said that like most Wells Gardner monitors, there were several revisions to the 4900 chassis and also some hot-fixes to the boards during production, some had cap 366 as an electrolytic, some had it as a non electrolytic cap, and others still omitted it entirely.
he told me you should look for any remains of legs in the holes that would indicate there was a cap there before, if it's not there go ahead and leave it out, don't put it in unless you have issues, because it may be a factory fix for something.
According to him several cap kit sellers omit this cap by default due to the fact that c366 is most often not there at all or not electrolytic.

[P-feif]

O.k. thanks. From what you are saying I think I should leave it out. There is no evidence of anything ever being installed at that location. Even solder on the pads is obviously from the factory and has not ever been touched.

So I'm going to get to installing the 3 color transistors and the resistors the Mr. Roberts provided (already did the BIG filter cap and mod). As a matter of fact I'm looking up resistor color charts to help me I.D. the old resistors as I pull them out. Mr. Roberts had sent me a separate e-mail explaining most of their locations but I'm double checking everything as I go. Just to be perfectly clear, resistors do NOT have polarity correct???

[lordkahless214]

resistors should not be polarized, just diodes and most capacitors, and there is no harm double or even triple checking your work, one mistake can mess up your project or send you looking for a problem caused by something you thought you fixed (we have all done that once)

you should have a beautiful picture on that monitor once you finish it and get it adjusted, the 4900 is one of the top 3 monitors ever made in my opinion.

 one thing to make sure you do on this chassis is reflow the solder on the RGB input headers and also the large rectangular resistors, since they can develop cracks over time it's good to do it now since you have the chassis out already

[P-feif]

resistors should not be polarized, just diodes and most capacitors, and there is no harm double or even triple checking your work, one mistake can mess up your project or send you looking for a problem caused by something you thought you fixed (we have all done that once)

you should have a beautiful picture on that monitor once you finish it and get it adjusted, the 4900 is one of the top 3 monitors ever made in my opinion.

 one thing to make sure you do on this chassis is reflow the solder on the RGB input headers and also the large rectangular resistors, since they can develop cracks over time it's good to do it now since you have the chassis out already

Sounds like good advice. I'll make sure to do that.

[P-feif]

O.k. been awhile since I had time to work on this thing. I got ALL of the parts that Bob Roberts sent me installed. All caps, all color transistors, all resistors, and the chasis transistor. I even crimped on a new power connector to the monitor board power wires, and then broke my (really cheap) crimp tool so I bought a new one this morning (still need to crimp the other side of the connector to the harnes in the cabnet). I'm almost ready to put this monitor back in but I'll like to do just a little bit of repair to the cabinet first, just easier to move and lay on it's side without the extra weight of the monitor. However there is one more thing that I'd like to do for this monitor before I put it back in the game. There is a thermistor at TH 501 on the board. The coating has pealed off of it and so since it's all appart I think that now would be a good time to replace it, need it or not. According to an e-mail that I got back from Bob Roberts he does not carry these and he even says that he thinks it will work just fine as is, but like I said it's appart now would be a good time to put a new one in. I visited a local electronics store and they didn't have it so I've got to do some searching. Anyone have any idea where I can get one? A new one not one pulled from a donor monitor.

Stats:

Board ref no. - TH 501
Name - Thermistor
Part number (according to the WG 4900 manual) - 201X0100-112



That's all I've got on it.

And just for John, they had two Wizard Of Oz pin ball machines in the back of the store. I think they wren't even pluged in.  http://www.abelelectronics.com/

[P-feif]

O.k. I found 3 free G07 monitors with possibly good tubes. My Mrs. Pacman manual says that the Electrohome tubes can be put into a WG4600 monitor. My game has an WG4900 in it. Anyone know if the G07 tubes with work in a WG 4900. The shop that has them put them outside for anyone to pick up free for nothing. I stopped to look at them but no one knew if the tubes would work in my WG 4900 so I didn't take any of them. Thoughts? Take them or leave them. Keep in mind I don't want to store them just to store them. Got enough stuff lying about as it is.

[P-feif]

I've been calling around today looking for a suitable replacement and I found this. Any chance that anyone knows the specs on this thermistor? I'm waiting for a call back from one of their engineers. If I can figure out which one will work then I'll pass along the info for everyone to use.  


http://www.ussensor.com/inrush-current-limiting-power-thermistors

[jtslade]

Your tube is an RCA tube, sticker in pics.. All of my G07's have RCA tubes. It's what I used on my G07 tube swap.

Also remember to use continuity setting on your multimeter to test from the soldered leg of each cap and follow the trace to ensure continuity, especially the one you mentioned that had a lifted pad on the pcb

[P-feif]

Thanks maybe I'll go back and look at those free-bee's.