Dead k4906 where to start?

goodnight144

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I recently bought a ms pacman out of someone's basement. They told me that it had worked fine until the monitor quit working and so they decided to sell it to make some room. So allegedly it was playing blind. There is no glow on the neck tube or any sign of life from the monitor.

I identified the monitor as a wg k4906 and using my cheapo multimeter I verified that there is power going to the monitor 123 volts (I'm assuming the extra 3 is because my multimeter sucks). I think the fuse on the chassis is good I can't see it because it has some funky tube thing over it but the resistance tested at 0 ohm with my multimeter.

So is there anything else I can try before just replacing the flyback?

Also is there a good guide at there for fixing these monitors?
 
check your B+ "R503", flyback is prolly good since your fuse is good. capkit might be a good place to start,might be one of those guys causing HV shutdown. check the HOT to make sure its not shorted and the V.R. check the 130v line on the edge of the chassis, make sure you have contiunty from one end all the way to the other end check/reflow solder around the standup resistor area. couple of ideas to try.
 
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flyback is prolly good since your fuse is good. capkit might be a good place to start,might be one of those guys causing HV shutdown. check the HOT to make sure its not shorted and the V.R. check the 130v line on the edge of the chassis, make sure you have contiunty from one end all the way to the other end. couple of ideas to try.

Thanks,
I'm kind of a newbie at this. I've done cap kits before but that is about it. How do I test the HOT and V.R. ?
 
like paul400 said test the VR and the H.O.T.

the fly on a 4900 rarely goes bad.

a good re-flow and a fresh set of caps is a must and you should be back in business.

Peace
Buffett
 
like paul400 said test the VR and the H.O.T.

the fly on a 4900 rarely goes bad.

a good re-flow and a fresh set of caps is a must and you should be back in business.

Peace
Buffett

Thanks, it looks like they are good. So I guess I will start with a cap kit. Is it possible to buy all the caps you need at somewhere like radio shack? If not I found some kits on ebay, but I would prefer not to have to wait on them to come in the mail.

Also I read where people were recommending to change flybacks if they had the white knobs. Is that just on certain monitors or should I replace mine since it has the white knobs?
 

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you will not find all the caps you need at the shak. most likely only 1/4 of what you need plus they are not HQ caps they are crap. and on top of that you will pay more for only 4-8 of them than you will with a kit from me

i have all the caps in stock including the filter cap.
all HQ caps.


a 4900 only needs a fly change if it is bad.

a K7000 and G07 are a must on the fly change.

Peace
Buffett
 
Ok so I've ordered a cap kit, so I guess I will start there. I actually pulled it from the machine and looked at it some more today. I didn't see any burnt parts or obvious deformities anywhere. I have confirmed that the fuse is good, r503 tested at 153 ohm on my meter, and I don't know what to think about the hot and vr because when I put my meter on them it goes up to like 1500 or so like it should but then goes down to 1 like it would if they were bad. Is there a chance they are both bad? Don't worry I'm going to get a better meter eventually lol.

Also I attached a picture of a part that the coating was flaking off. I'm guessing that it's due to age, is it a capacitor and should it be included in the cap kit I ordered?
 

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that part that is flaking is your thermistor they flake like that from age.

it will be fine and not needing replaced.

Peace
Buffett
 
Ok so I've ordered a cap kit, so I guess I will start there. I actually pulled it from the machine and looked at it some more today. I didn't see any burnt parts or obvious deformities anywhere. I have confirmed that the fuse is good, r503 tested at 153 ohm on my meter, and I don't know what to think about the hot and vr because when I put my meter on them it goes up to like 1500 or so like it should but then goes down to 1 like it would if they were bad. Is there a chance they are both bad? Don't worry I'm going to get a better meter eventually lol.

Also I attached a picture of a part that the coating was flaking off. I'm guessing that it's due to age, is it a capacitor and should it be included in the cap kit I ordered?

thats the reading you want 1500 and above , then to 1. if it read 0 your part would be bad. R503 is where you carefully test your B+, ground gthe black lead then on the side closet to the fuse when working should be 130vdc, right now it prolly is over 150vdc and in shutdown.
 
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thats the reading you want 1500 and above , then to 1. if it read 0 your part would be bad. R503 is where you carefully test your B+, ground the black lead then on the side closet to the fuse when working should be 130vdc, right now it prolly is over 150vdc and in shutdown.

Great, than I guess the hot and VR are good. So I tested the R503 using the resistance setting on my meter which gave me 153 ohms with the monitor unplugged from the machine. Am I suppose to test it on the DCV setting? And is the monitor suppose to be powered when I test that? I appreciate you guy's patience with me and thanks for the help.
 
Ok so I got the cap kit and installed it and I'm still getting nothing. I never actually measured the voltage on r503 before I did the cap kit but now I am get 9 volts. I attached the pic of the multimeter to make sure I was doing it on the right setting. I used the black lead on the side closest to the fuse and the red on the other.

What should I try next?


IMAG0115_zpsdedf49e5.jpg
 
move your setting to 200dcv. put your black wire to ground/ frame of the monitor is a good place, just stick it in one of the many holes in the frame. then test the red wire on R503.
 
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take a pic of how you installed the filter cap from the bottom side.
i want to make sure you got it all connected correct.

also re-flow everything on the 130v rail it is labeled on the under side of the chassis.

if this path is not making contact it will shut down the monitor.

Peace
Buffett
 
take a pic of how you installed the filter cap from the bottom side.
i want to make sure you got it all connected correct.

also re-flow everything on the 130v rail it is labeled on the under side of the chassis.

if this path is not making contact it will shut down the monitor.

Peace
Buffett

next thing I would have suggested, the 130 trace is long make sure you have continuty all the way across it.
 
I measured the continuity and it seemed good all the way across. I went ahead and re-flowed the solder though and here are the pics of the bottom of it and the jumper I made.
 

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something in your pic does not seem rite to me.

this should clarify it a little better.

Peace
Buffett

4900filtercap.jpg
 
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test your B+ before you go any further, just to make sure your troubleshooting the right area, the red lead goes on one side of R503 and ground the black lead to the frame.
 
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