Sega/nanao mc2000s.. need some help with veritcal collapse

mrbill2084

Well-known member
Joined
Oct 6, 2005
Messages
12,572
Reaction score
1,518
Location
san jose, California
Sega/nanao mc2000s.. need some help with veritcal collapse

Ok, a few weeks ago I got a nice full size sega turbo upright.. It had a mc1600s (yes, its not a 20")monitor in it. It was working, but the screen had the jitters.

So I go to bob's wesite to order a cap kit, and he does not sell it. He has a kit for mc1400s and and mc2000s.. So I ordered the 2000 kit. everything matched up perfectly. So I drop it back in the cabinet, fire it up, and it seems a litttle brighter, maybe a little less jitter(loud game audio seems to make it jitter more).

So I play 2 games on it and it looks like its working. Power it off to move it and when I power it back on, and now it has a vertical line. Any ideas? I have not really worked on mc2000's before.

what makes things a bit weird is that I ordered 2 other mc2000 cap kits for some old monitors I have lying around. 1 has light nintendo burn on it. Af the cap kit, the monitor looks like it has ac wave going on in the screen. It does not want to make a good pic(sort of like its out of focus).

the other mc2000 also has a vertical collapse. For a brief moment, it had a full pic, but it went back to vertical collapse.. Any ideas? the Turbo had not been turned on for several years. Tubo's boarset is a mess, but I don't think it could be a problem with its pcb...

I also was having fun with a pair of sanwa v21 chassis. I am trying to fix a monitor for outrun. so I recapped 2 unknown chassis. first 1 looks totally doa. So I connect the 2nd one. Its making HV, but I see no pic. It was on for maybe a minute, and then I start to see arching from the ground wire on the tube to its pin in the neckboard.. Never worked on a sanwa before. any ideas?
 
From my repair guide to the MC2000S:

Vertical Collapse problem: Check resistor R416 (22 ohm fusible, half watt), vertical output transistors Q401 & Q402 (both are type 2SD1138), and capacitor C523 (originally a 47 uf @ 50 volt, but should be changed to 100 uf @ 50 volt). C523 is located inside the cage around the flyback. Check tantalum capacitor C408 (10 uf) as it may be shorted.
 
Back
Top Bottom