SI - characters scrolling fast across screen

Arthur Dent

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So I just got the power supply working and fuses replaced. Powered up the game and when the monitor comes up, at various lines where there would probably normally be characters, they are scrolling across the screen extremely fast continuously.

Going to scour the threads but hoping someone can pont me in the right direction. Am hoping to have it running by Feb 2nd for my daughter's birthday party.
 
Yeah, vertical sync problem of some sort. Could be monitor-related, could be PCB-related.

We hope Tighe is correct, and it clears up with a little monitor adjustment...
 
I was wondering about that. It just looked like the characters were being generated to scroll across the screen rapidly but hopefully it is as simple as adjusting the vertical sync. Thinking there is probably more going on though as trying to start a game results in no change and there are no sounds either. Trying to coin up a game only advances the counter.
 
I do see a change there, at least I think I do. Thats definitely the vertical hold on the monitor (at least that initial problem). Turn the game off, and try turning the vertical hold pot both ways until it stops a few times. After 30+ years they get dirty and moving them around a bit helps clean em up. Then turn the game back on and see if you can dial in the vert hold.

Coin counter will almost click no matter what..its practically hard-wired to the coin input so the boards can be fubared and it will still click.

If the game plays but you have zero sounds...your power supply may have a blown/open diode yet and/or check the fuses again to see if any have blown. Also check the speaker to see if the wires haven't gotten yanked off at all, and make sure the lower of the two connectors on the daughterboard are making good contact.
 
If it is your power supply I nearly completely rebuilt mine and I can give you some advice as mine was not just the caps but the final problem was a concrete resistor. I have a few extras.
 
So the vertical hold was the main culprit. I managed to get a better picture but it is still very distorted. The vertical hold pot was very sensitive and difficult to adjust. Looking at the picture, I am assuming I need to do a cap kit on the monitor chassis. I plan on using some tuner cleaner on the pots as well. Let me know what else you think I should check or replace while I am doing that.

Here is what it looks like now..


I also removed the monitor overlay that was in there. Can anyone tell me what this is? The small individual overlays I expected were underneath this one but I ordered new ones as they are in rough shape. The wide green strip was stuck in one area to this one and removing this one causes some clear areas to be left behind. You can see the green that stuck to the overlay in the pic.

overlay_zpsfa07cb43.jpg


Still no sound at all. I guess the speaker has been replaced as the one in there is connected via wire caps which I checked.

I stuck an 1813 bulb in as none of the lights were working (aside from the blacklight) and it lit up so I ordered some 1895 bulbs.

Controls seem to all work but some stick. Not too worried about them at this point.
 
So the vertical hold was the main culprit. I managed to get a better picture but it is still very distorted. The vertical hold pot was very sensitive and difficult to adjust. Looking at the picture, I am assuming I need to do a cap kit on the monitor chassis. I plan on using some tuner cleaner on the pots as well. Let me know what else you think I should check or replace while I am doing that.

Here is what it looks like now..

You should probably cap the monitor.
 
check the signal ground from the pcb to the monitor as well. and loose / cracked solder joints on the monitor.
 
So I will be working on the monitor, but since I was hoping to have this running by Feb 2nd, I am thinking of having Elektron Forge work on the boards for me. Mainly to get the sound working. Hoping pretty much everythign else is ok.

Has anyone here used them before and can you tell me what your experience was like? I emailed them and got a quick reply from Alex who seemed very polite via email.
 
So I will be working on the monitor, but since I was hoping to have this running by Feb 2nd, I am thinking of having Elektron Forge work on the boards for me. Mainly to get the sound working. Hoping pretty much everythign else is ok.

Has anyone here used them before and can you tell me what your experience was like? I emailed them and got a quick reply from Alex who seemed very polite via email.

Did you check your +18v on the power supply?
 
Did you check your +18v on the power supply?

Nope. Not sure where my meter is at the moment. Well, I know it is in the basement but the basement is in complete chaos right now and I am trying to reorganize it by the end of the month. The PS was bought as "fully working" so if it isn't, I will be having words with the seller.

I have a million things I am trying to get done by the end of the month and I decided I really don't have the time to fix this myself if I want to have it running at the end of the month. I think I can rebuild the monitor by then...maybe...if I am lucky. I thought about just ordering all the parts for the boards that I might need so I would have them onhand when, say, I get the 18v working only to find out that several of the LM3900s need to be replaced.

But I thought it might be better to try a repair service and it looked like Elektron Forge might be a good place for SI repair.

Just too much on my todo list at the moment. I was replacing some light switches in my house as we had some bad ones...its a really old house...and I figured it should be an easy job. Turned out that several of the old 3 and 4 way switches were wired differently than the replacements and it took a lot of extra time to figure that out with my meter....which makes me think I might know where I left it now. ;)
 
Nope. Not sure where my meter is at the moment. Well, I know it is in the basement but the basement is in complete chaos right now and I am trying to reorganize it by the end of the month. The PS was bought as "fully working" so if it isn't, I will be having words with the seller.

I have a million things I am trying to get done by the end of the month and I decided I really don't have the time to fix this myself if I want to have it running at the end of the month. I think I can rebuild the monitor by then...maybe...if I am lucky. I thought about just ordering all the parts for the boards that I might need so I would have them onhand when, say, I get the 18v working only to find out that several of the LM3900s need to be replaced.

But I thought it might be better to try a repair service and it looked like Elektron Forge might be a good place for SI repair.

Just too much on my todo list at the moment. I was replacing some light switches in my house as we had some bad ones...its a really old house...and I figured it should be an easy job. Turned out that several of the old 3 and 4 way switches were wired differently than the replacements and it took a lot of extra time to figure that out with my meter....which makes me think I might know where I left it now. ;)

Well, the +18v is for the audio, if it is not right then you get no audio. Find your meter and test it. You are wasting money if the PSU is bad.

Here is how to test:
http://www.elektronforge.com/TestMdwPS.htm
 
Well, the +18v is for the audio, if it is not right then you get no audio. Find your meter and test it. You are wasting money if the PSU is bad.

Here is how to test:
http://www.elektronforge.com/TestMdwPS.htm

Yes, I have that bookmarked. I meant to do that but did not have time...which is the issue. Depending on what this costs me it will totally be worth it to pay someone else to test/fix it for me since doing it myself will eat up precious time that I need for the rest of my todo list. The boardset and PS are already boxed and in the shipping dept of my work where I am now. I had pretty much decided to go ahead and do it but then I thought maybe I should check to make sure no one says "NOOOO!!! DON'T USE THEM!!!!". But no one has...although no one has endorsed them either. If someone had good reason for me not to use them, I was going to go pull my box from shipping. Guess I will report back and let you know what my experience with them was like.

I hate that I am sending this out to be repaired but I have to be realistic about what I can get done in the time I have available. I will still have at least a dozen project games left to do myself. ;)
 
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