Arcade monitor issues

[anarkotiko21]

Hi there!

this is my first post!

i recently bought an arcade machine    but , once i installed the board of street fighter 2 and turn on the machine , i had 2 problems ,

1- red color missing , i already fixed that changing a "potenciometro" (cant remember the English word right now)

2- (this one is driving me crazy) , the image looks like i show below and i couldn't find the cause , any ideas plz ?







i would love some help
cheers! and sorry for my English

[anarkotiko21]

oh , forgot to add:

the arcade monitor is a NOKIA A66EAF00X01, couldnt find anything in internet about it   

also: i know this isnt about the game board becose the man who sell me the cabinet told me about no red color (fixed) and "moved" image (NOT fixed yet!)

[grantspain]

nah,your tube is a nokia a66-your chassis is something else mate-thats why you can't find any info

to me it looks like either the sync is on the wrong connection or you need to tweek your horizontal hold pot

take a photo of the monitor board if you want to know what it is

[anarkotiko21]

Hi! thnxs for the answer.

my chasis is RODO-JW888A and i couldnt find anything about it on the net.

I cant fix it tweaking any pot , already tried

what you mean exactly with "in the wrong connection" a wire ? ?


Some images:











thanks !

[grantspain]

your sync looks correct as it only goes to one place
i have the schem for this,i got it from www.pentranic.com website and it is marked as ch888 chassis

probably could do with some caps done on this,if you look at the schem and trace the sync then that should point you in the correct direction

wtf happened with the anode lead from the flyback

[anarkotiko21]

hey , thanks for the schem , im trying to figure it out , so , you  mean i might need to change some capacitor ? how can i find the one making trouble?

he , the anode lead was looking a little suspicious , so i did that "fix" just in case

[anarkotiko21]

Hi !

A little update :

* I couldnt really figure out the schems , are you shre is the same chasis? (Rodo JW-888A)

* i replaced the caps : C801 , C313 , C901 , C407 , C326 and C499 - but nothing changed

* also , moving the H.Hold pot i coud get somthing like this :



*and someone told , looking that picture that the wrong cap probably is around here : (look inside the red square) , wich im going to check now






thanks for any feedback

[grantspain]

make sure the sync is showing continuity to the jamma pin  p and the video ground is good to pin 14

i am sure they are the same chassis,give me a random component value and position number

[anarkotiko21]

random component and value:

47uf 16V - c121
470 uf 25V - c499
390 omhios - r399



im going to check that what you said

thanks again mate

[anarkotiko21]

Hey there!

still didnt check what you suggested , but  i rplaced some of the clindric caps in the section inside the red square in the photo i showed to you ...(nothing changed)

but i have a couple of questions:

1 - the red caps (i think theyre also caps) should be replaced too - i ask becose they look to be diferent kind or somthing ...dont know?

2- see the 3 red caps , close to the 3 cilindrics blue caps , inside the red square ? , i noticed that if , being the machine working , i put a finger there (without moving it or pressing hard) the image start moving  a little in one , a lot in the other , could this mean tha problem is there?    or is it normal ?


again , thaaanks a lot !

[grantspain]

don´t worry about the red caps,they very rarely go faulty-they are polypropylene type

don´t stick your finger onto the chassis when its powered up unless you want a nice big electric shock,check around that area for bad solder joints

maybe that the wrong schem then

[anarkotiko21]

HI there

i replaced every caps in that area , including the polypropylene ones ... and the problem is still there   

what else can i try ?¿

[grantspain]

have you tried a different game board on this yet?

[anarkotiko21]

Yes , the guy who sold me the cabinet had the same issues (no red color - i already fixed that- and moved image) and he didnt even used a jamma board but a mame , he also buyed the monitor with that issues  and he didnt know electronics so he didnt really touched anything. so , im sure is not the board.

what about the IC ? (is the black chip isnt it? ) is the only thign in that area i didnt replace , dont know ... 

[grantspain]

hang on a mo,how many pins do you have on the video input plug of the chassis??

[grantspain]

and i got your schem,its the ch988 chassis on pentranics site and if i am correct you have the white sync wire connected to the vertical sync pin when it needs to be on the horizontal sync pin of the video input plug

[anarkotiko21]

mmh , 5 ? blue , white , green , black  wires? - thas what you mean-? whats on your mind ?

( i just read yor new post when i finish wroting that, so im going to check that right now )

[grantspain]

the white wire(sync) goes to its own little connector,i bet there if you remove the white plug you will see 2 pins on the board-you need to put this on h/s pin not v/s

[anarkotiko21]

is there a vertical pin in the input? i thought 3 pins were for the colors , 1 for ground ,and one for hor.sync

the input in teh chasis says : R , G , B , E ,S

mmh , as far as i know , the board didnt have a v/s either the monitor input .... but well , im new at this , maybe i didnt saw it ....

[grantspain]

o.k look at the chassis,do you have 2SA673A transistor at position Q201 and is the something marked J107 near to it

[anarkotiko21]

looking for the position ... having some troule find it do ...

i see q401a q803 q304 q901 q106 q105 q104 q107 q108  q907 q903 .. maybe some other , but no much

[anarkotiko21]

i did find position j107...

[grantspain]

o.k is ic 102 a hd74hc86 and ic302 a la7833?
what is in position j107?

[anarkotiko21]

found somthing that coyukld be pos. q201 , cant eally say becos the suposed 2 is not clear , and is highly probable is really an 8,   the transistor there is : c2555 (the only thign i can read , think theres  more)

ic 302 = i thin says m18gan5521

ic 301 = 1H1HA11235

ic 102 =  cant find it yet

j107 is just a "conector" (thats the word?) like metal wire..

[grantspain]

go and download from the pentranic site the schem for ch988 because i am sure that is what you have.

[anarkotiko21]

the page says only
CH-888 (Analogue – CGA) - 14", 17", 19", 20"
   CH-250 (Analogue Chassis – VGA) - 14", 19", 29"
   CH-1450 (Analogue Chassis – VGA) - 14", 20"
   CH-666 (Analogue Chassis – CGA/EGA/VGA) - 28", 29", 38"
   CH-2948 (Analogue Chassis – VGA) - 25", 28", 29"
   VT-970 (19” Digital Chassis - VGA) - 17", 19"
   VT-2170 (21” Digital Chassis - VGA) - 21"
   Alpha 19-130 (19” Digital Chassis – VGA) - 17", 19"
   CH288 - CGA (Analogue - CGA) - 26", 29", 33", 38"
   CH288 - Switchable (Analogue - CGA / EGA)  - 26", 29", 33", 38"

where is ch988 ? 

[anarkotiko21]

Hi! 

hey grant , thanx a lot for the schems!

i think that chasis is higly similar but definitly not the same , anyway , i think i found the problem! 

he flyback is working at 60 volts instead of 110 !

how can i fix that ?

thbxxx

[grantspain]

Hi! 

hey grant , thanx a lot for the schems!

i think that chasis is higly similar but definitly not the same , anyway , i think i found the problem! 

he flyback is working at 60 volts instead of 110 !




thbxxx

are you sure,i doubt you would get any ht whatsoever if the B+ is that low

where are you reading this voltage btw?

[anarkotiko21]

mmh , im not sure how to explin for where i am reading... from two fuses?
the thing is ... someone told me he had a similar problem becose his flyback was working at 70v instead of 110 .... so i checked.... and also , i have one chasis exactly the same but broken , i pug it to comparision and while the old broken one give me 110 , this one gives me 60 ....

[grantspain]

never heard of a flyback operating under it B+ level,maybe someone is confused

to meter the b+ you need to find the output from the power supply section


where are you based as i think you should think about sending for repair,to me this looks like a fault on the horizontal sync circuit only

[anarkotiko21]

I undersatnd , but in my country i dont know of any place who fix arcade monitors , and know someone who tried and the guys didn know how... and , im still feel like trying

anyway , i probaly wasnt talking about B+ , but theres somthing wrong where i check , becose must said 110 , according to the older chasis, but said 60, obviously the error could be originated in other place.how can i be shure about the outpout from the power supply ?

i found two other irregularities , in the zone you told me, and also in the zone where i get that mismatch of volt comparing with the older chasis.

testing continuity and comparing it with the older chasis i found that my chasis have this irregularities in the hor. sync:

1)the upper pin of the H.posi pot have continuity with boths the pin above him , when the continuity should be only in the left one.

2) Also , the resistence thats just above of H.pos gives me continuity , wich , not only is not suposed to give me according to the reference of the older chasis, also , and this may be false cose i dont know, isnt resistance supposed to not give continuity ever? ------wait , i just saw that the resistance pins are there , but in the other part , i dosnt sime to be one .... in boths chasis , so , i dont know if the mismatch is important

[grantspain]

try replacing the hor hold and position pots,what country are you from?

[enusbaum]

That CRT board looks a LOT like mine. In fact, almost identical to mine which is a Wei-Ya C829HR .

Might want to see if you can find anything on their site:

http://www.weiya.com.tw/