Donkey Kong Monitor Issues

[calz]

Checked all of the wires and moved stuff around with no affect. Thinking it has to be something with either the wire I ran due to the board burning or maybe a cold solder. I did triple check everything before reinstalling though. This is the best I can get it to look by messing around with the adjustments:



So looks like I'll have to discharge again... this is the tool I made to do this:

[mrazy1]

Ok I think I found your problem.. I was looking at the pictures you sent and the schematic. I noticed on the schematic that the cap was connected to pin 23 and the other end to r162 but then goes to r221and r220. To me this doesnt make since. Why are would you want to clamp down the gained amp sign before you clean up the signal???.. NO... you wouldnt get the gain you wanted.. but this circuit doesnt make since anyway. I noticed that that pin isnt connect... on some monitors... Why because why would you need to Amp. the sync again??? but that what that circuit does... for whatever reason. So looking at the pictures you sent. I was right (PLEASE LOOK AT PICTURES) Blowing up your pictures I can see the trace lines(Light Green) and I can see where pin 23 goes. it goes to r162 first.. Well that make since to me, limit the current after you clean out the DC.  So just do what i have written on the picture and I think you will be good. I will be honest here but I THINK its right. I THINK the positive side of the cap goes to r162 and the negitive side goes to r221 r220 which is the jumper wire that go to both those resistors.. Maybe someone that has this type of monitor can help here. I do know the schematic is WRONG...

[lilshawn]

yeah, it's hard to tell, but i think he's right.

there is a lot of extra flux on the board there covering up the track so it's hard to see. but, it does look like that wire you have jumperd there shouldn't be there... you are bypassing the resistor.

[calz]

Ok I think I found your problem.. I was looking at the pictures you sent and the schematic. I noticed on the schematic that the cap was connected to pin 23 and the other end to r162 but then goes to r221and r220. To me this doesnt make since. Why are would you want to clamp down the gained amp sign before you clean up the signal???.. NO... you wouldnt get the gain you wanted.. but this circuit doesnt make since anyway. I noticed that that pin isnt connect... on some monitors... Why because why would you need to Amp. the sync again??? but that what that circuit does... for whatever reason. So looking at the pictures you sent. I was right (PLEASE LOOK AT PICTURES) Blowing up your pictures I can see the trace lines(Light Green) and I can see where pin 23 goes. it goes to r162 first.. Well that make since to me, limit the current after you clean out the DC.  So just do what i have written on the picture and I think you will be good. I will be honest here but I THINK its right. I THINK the positive side of the cap goes to r162 and the negitive side goes to r221 r220 which is the jumper wire that go to both those resistors.. Maybe someone that has this type of monitor can help here. I do know the schematic is WRONG...

Thanks! Excellent information! I am going to pull this out tonight and give a shot at what you suggest. I started to last night but turned chicken before the discharge and decided to give another day :-). I also noticed that my power cord is missing the ground terminal and bought a new power cord today to fix.. any chance this could be causing the problem as well?

[lilshawn]

Ok I think I found your problem.. I was looking at the pictures you sent and the schematic. I noticed on the schematic that the cap was connected to pin 23 and the other end to r162 but then goes to r221and r220. To me this doesnt make since. Why are would you want to clamp down the gained amp sign before you clean up the signal???.. NO... you wouldnt get the gain you wanted.. but this circuit doesnt make since anyway. I noticed that that pin isnt connect... on some monitors... Why because why would you need to Amp. the sync again??? but that what that circuit does... for whatever reason. So looking at the pictures you sent. I was right (PLEASE LOOK AT PICTURES) Blowing up your pictures I can see the trace lines(Light Green) and I can see where pin 23 goes. it goes to r162 first.. Well that make since to me, limit the current after you clean out the DC.  So just do what i have written on the picture and I think you will be good. I will be honest here but I THINK its right. I THINK the positive side of the cap goes to r162 and the negitive side goes to r221 r220 which is the jumper wire that go to both those resistors.. Maybe someone that has this type of monitor can help here. I do know the schematic is WRONG...

Thanks! Excellent information! I am going to pull this out tonight and give a shot at what you suggest. I started to last night but turned chicken before the discharge and decided to give another day :-). I also noticed that my power cord is missing the ground terminal and bought a new power cord today to fix.. any chance this could be causing the problem as well?

no, but ive seen weirder. don't worry yourself about the discharge. it's peanuts. It's no worse than getting punched in the arm by your friend if you happen to get shocked. iv'e done it a few times myself. it's not a great feeling and not something i try to do, but it happens...and usually when i get lazy and try and do shortcuts (not recomended)

doing it while it's on and powered on the other hand is something REALLY not recomended... and WILL kill you with 100% certainty.

[calz]

haha, thanks, that actually is reassuring. When I first took this out last time, I think it sat idle long enough where there was no charge so I was nervous about using the tool that I built for this... still am :-)

Also, from the pictures and comments from mrazy1... the C162 cap is non-polarized so there is no positive/negative from what I understand, so I am not understanding where to change things around now :-).

[mrazy1]

  Yea I been zapped a few times boy I tell yea it better then coffee....  But not recommended for daily use.....

Since it not polarized as the schematic show that it isn't but the symbol seems to indicate that it maybe a Special cap. (maybe ESR) but if the one you have for a replacement isn't then it doesn't matter which way it goes... just solder them in the way I posted in the picture and don't worry about the + or - signs I put there.. GOD BLESS

[calz]

haha, cool. So one verification.... Should I still use the wire or just solder these points together? From the pics looks like I can just solder them together? Also as luck would have it I found there is a pretty big arcade supplier close by and went and grabbed another cap kit. Also thinking my flamethrower might have damaged C162 as well :-).

[mrazy1]

  Flamethrower??? Got a butane desolder??    That in the hands of a newbe is like child with a real flamethrower LOL. But hey learning right?? Yes on soldering cap wires to the those point. Remove wire... also if you can clean you board up a bit.. remove solder splatters and clean the flux off the board.. What are you using for solder anyway a cup of flux with soild solder??? I pray not,,,  60/40 is good LOL.

Ok You all think I am nut will here proof  Yes I use the BIG GUN LOL

[calz]

  - you are hilarious and that is quite impressive with that solder gun. Imagine if I used that? There would be holes in the board  .

SOOOO, I took the board out, cleaned it up, soldered like you said, checked for cold and overflow. There is now NO verticle or horizontal problems now and the colors look great... THANKS! for the advice. Still doesn't look right though that I am not sure what to make of this (the big line on the screen is from the camera not the monitor):


 

 

[lilshawn]

looks like a rom / ram chip problem...

give them all a push and see if it goes away.

[calz]

Thanks. Pulled the board out and reseated them all... didn't make a difference (argh).

[mrazy1]

Well Maybe someone else can help you here Glad to see it up and running. Looks to me that your brightness maybe to high.... go into the test patterns of screen color bars(If that game has that) and set all you colors Black needs to be black and white need to be white... But I think someone ere has posted how to set this up. I know Lilshawn Knows more about this then I do. I can set it myself but do not know how to tell other how to set colors.. and with the other problem you have.. Did you Change C202?? and I would check connection first. Should be the first thing someone should do first always. Plugs, Connection and and fuses... Then Block out what is working and what is not.. GOD BLESS Great Job by the way. May not be on for a will.. I have fixed all those games this guy had and he is happy for now cant convice him that they need cleaning once a month. but I guess when they brake I will be doing it then HAPPY NEW Year P.S. Looks a little fuzzy too.

[mgb]

I had a similar issue with a DK where I had pulled any socketed chips and cleaned the pins (typical of many old boards)

[calz]

Well Maybe someone else can help you here Glad to see it up and running. Looks to me that your brightness maybe to high.... go into the test patterns of screen color bars(If that game has that) and set all you colors Black needs to be black and white need to be white... But I think someone ere has posted how to set this up. I know Lilshawn Knows more about this then I do. I can set it myself but do not know how to tell other how to set colors.. and with the other problem you have.. Did you Change C202?? and I would check connection first. Should be the first thing someone should do first always. Plugs, Connection and and fuses... Then Block out what is working and what is not.. GOD BLESS Great Job by the way. May not be on for a will.. I have fixed all those games this guy had and he is happy for now cant convice him that they need cleaning once a month. but I guess when they brake I will be doing it then HAPPY NEW Year P.S. Looks a little fuzzy too.

Thanks, yup, I did change C202, and checked all of the connections. Will keep poking around at this but pretty frustrated. You have a GREAT New Year as well and good getting that guy to clean his games :-). Thanks again.

[calz]

I had a similar issue with a DK where I had pulled any socketed chips and cleaned the pins (typical of many old boards)

I did pull the board tonight and reset but did not clean. The chips did not look too bad but I will try this next. Did you clean yours with Scotch Brite or something else? Also, having a hard time thinking it is not the chasis or a solder point... does this look like the monitor is OK and the board could be causing this? You think pulling the chassis out again and redoing some of the pins could solve this? From what I read it looks like board to me, but when I got this game I never saw it play normally so do not know what it was like before the cap kit. Just want to get this one done (still have some cosmetic things to do, add it to the collection and move on to the next one :-)). Thanks again and have a GREAT New Year!

[mgb]

When I clean rom pins, I use a dremel tool with a wire wheel on it. This needs to be done very carefully by almost not even touching the pin and using your fingers for support.
The ones I always find the worst are old Midway boards like Galaga and Pacman. Sometimes just from the gunk and pin rot, the legs will break off and then they need to be repaired. I don't remember having any legs break on the donkey kong though.

[mrazy1]

I think you are correct.. Could be board problem not monitor