Sega/Nanao MC-2000s cap question

Mitsurugi-w

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I'm doing a cap kit on this monitor and I have a question. The cap kit says to replace C523 with a 100uf 50V cap. The cap I pulled from the board is 47uf 50V. Is it ok to replace this one? I got the kit from Bob.

Also, it says to replace C501 but my chassis doesn't have one installed. Actually this is the third I've worked on that didn't have a cap installed at this location. Cross you fingers for me, the other two MC-2000s chassis still don't work...
 
Is your chassis a "straight up" MC-2000s? Sega/Nanao made a handful of different versions of the MC-2000s series. The most common is the 2000s, but there's others....like a MC-2030s. They can have a cap or two different. I worked on a 2030s not too long ago. I know it had a couple different....it also took a different flyback. A lot of people just call them all MC-2000s, even though there is subtle differences.

Edward
 
Yeh, sounds like you have a capkit for an MC-2030-S which has slightly different caps than a kit for the MC-2000-S.

Regardless though, a long time ago there was a Star Tech Journal bulletin that mentioned upping the value of C523 from 47 uf to 100 uf @ 50 volts. The original cap was a frequent failure item.
 
Yeah my chassis is definitely the MC-2000s. None of my chassis had the C501 cap installed even though the schematics clearly have it listed. I'm a schematic novice but it appears to be part of a sync inverter circuit. The entire circuit is unpopulated.

As far as C523 goes, if the service bulletin says to replace it then I guess that may explain it. I'll give it a go.

While I'm talking about this chassis type, I have one chassis that has nothing but a bright white screen. I found somewhere that a cap on the neckboard was the usual cause of this. The page was gone so I couldn't see which cap it was. Does anyone know?

Finally I have one other chassis that I could never figure out. It has vertical collapse. It was the first chassis I tried to repair myself. I basically shotgunned components a few at a time. I replaced all caps first. Replaced R416, both transisters in the vertical circuit, several diodes and some others. I went back and forth with Randy Fromm on this one. I never got it figured out. I really want to get all of these working.

So, Ken, I noticed while researching that you had several of these with bad C408 tantalum caps. How do I test a tantalum cap to see if its open? Thanks for all the help!
 
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A tantalum capacitor is just a special type of electrolytic capacitor usually in the 1 uf to 47 uf range. Testing them is like testing any other electrolytic capacitor. If it's shorted you'll see that on an ohm meter. If it's open or off value you need either an ESR meter or a digital readout capacitor meter.
 
Ok, cool. Well as for this monitor. The cap kit didn't work. I already tested R416. 23Ohms. Still have vertical collapse. I think these MC 2000-s monitors are my bane... *sigh* Time to start pulling other components....
 
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