Arcade Otaku - アーケード オタク

And what do we have here?, this one was working fine since it arrived, until today when I was testing some boards:





what could be the cause of this, I already checked for loose cables but all seems to be fine.

I have been told that it could be a faulty transistor on the neckboard, are those the ones with the white ceramic enclosures?

Hello, i think your transistors have 3 legs and metallic heatsink.

Ah, those ones, merci.

Meassured the transistors and all of them gave almost the same readings, I didn't take them out though, do I need to remove them from the board?

There is one thing you can do very quickly to be 100% sure without buying spare parts or needing expensive equipment: find the transistor driving the green and swap it with that of blue or red. Depending on whether the defect moves along or not you have your answer.

Yeah I guess I could have done that, but I have just moved my tests tubes into the warehouse so this will go into the scraps box until I can find someone more knowledgeable whom I can send it for repair.

Aaaand... it's fixed, if this ever happens to you just replace those mother f*****s marked in red here:



looking good so far

thats the spark gap

This things in my hands are full of spark gaps, how I have not killed myself yet? I have no idea .

I recently got an MS9 chassis that i will try to repare. Besides a short-circuited HOT (already ordered this) i noticed that one of those spark gaps has a broken leg.

Can you please tell me where you bought them and the exact reference?

Thanks in advance.

i tend to take them from old neck boards i have lying around

I bought them locally on a TV & Radio repair store.

Neither of my old chassis have this and i can not find them locally or online.

If any of you guys could provide an online link i would be very grateful.

They are useless as the socket has its own spark gaps.

PrincessPrinPrin wrote:They are useless as the socket has its own spark gaps.

I'm sorry but i don't understand this. The OP said he had a color problem and it was fixed with the replacement of the spark gaps. Do you mean that if i try my chassis with one broken spark gap, that won't affect the image?

RMRM wrote:

PrincessPrinPrin wrote:They are useless as the socket has its own spark gaps.

it was fixed with the replacement of the spark gaps.

The removal would have been enough.

Now i think i undestand:

This means that if 1 out of 3 is bad (in my case), i should remove all three, right?

Sorry to insist, just want to make sure

RMRM wrote:Now i think i undestand:

This means that if 1 out of 3 is bad (in my case), i should remove all three, right?

Well, no because they are independent of each other so removing the bad one would be enough. There are four spark gaps on the MS9 neckboard, one for each of the RGB lines and one for the heater. There is also a place to put one for the G1 but it's not used. What I meant is that these devices are not really necessary as modern sockets were designed to have built-in spark gaps so external ones are a bit superfluous. In fact you don't find them on other monitors like Hantarex,Wells Gardner etc. You do find them in really old monitors, for instance Hantarex MTC900 (ca. 1981), as the sockets didn't have this feature back then. In any case I'm a bit sceptical about picture issues being caused by bad spark gaps, maybe it can happen with those where the gap is filled with noble gases (argon or neon) like the MS9 ones.

Once again, thanks for the precious answer.

I will simply remove it and try the chassis as soon as i get the replacement parts needed.