Dead WG K7193 Chassis

NeoGeoVA

Member
Joined
Nov 9, 2009
Messages
99
Reaction score
0
Location
Virginia Beach, Virginia
My chassis has died. I replaced the flyback, HOT, VR and did a cap kit. I have no idea where else to look for an issue. I have checked all of the commonly known issues and need to know of some uncommon issues that may cause a board to not power up.
 
Last edited:
What is your B+ measuring?

Did the monitor work before you "fixed" it?

Did you remember to put the insulators between the VR and HOT when you replaced them?

Is the fuse blowing?

Check all the solder and trace continuity in the area behind the flyback....
 
What is your B+ measuring?

Did the monitor work before you "fixed" it?

Did you remember to put the insulators between the VR and HOT when you replaced them?

Is the fuse blowing?

Check all the solder and trace continuity in the area behind the flyback....

Yes, the monitor worked before I repaired it.

I guess this is something that comes with being new to monitors, but I don't remember the HOT having an insulator pad, just a ton of thermal paste. The VR did have an insulator pad behind it and I put it back behind it when I replaced it, but I take it by your question, that the HOT should have had one too.

Where can I get one and is the HOT damaged now because I didn't have one?
 
yup probhably and mabye more as well.

Is it blowing the chassis fuse? If so, itll probhably need more then just the hot but that would be a good place to start.
 
It's not blowing fuses, but I now remember that when it went dead the second time I had only replaced the HOT. I replaced the other parts after it went dead, so I'm thinking that is the problem. I knew it was most likely a mistake on my part, but you have to learn at some time. I have ordered a new HOT and an insulator pad. I'll post an update after I install the part. Thanks for your help.
 
Are you POSITIVE the fuse is good? Do you have a multimeter? Don't chuck the old HOT yet, it may be fine.

With a multimeter, check the resistance on that large white resistor on the back right corner that sticks straight up in the air. If that's good (the value is printed on the side of it), check all the diodes in that area. See if any of them are shorted out.

Then check the diode right beside where the yoke plugs in.

Then check the 1 or two large caps underneath the metal cover that the HOT bolts to. See if they're shorted from one side of the cap to the other, and then again if there's another one next to it.

Then check and see if the middle leg of the hot is shorted to the metal plate the HOT is mounted to.

When the monitor first comes on, do you hear it snap crackle and pop?

Let us know, we can get this sucker going!
 
Are you POSITIVE the fuse is good? Do you have a multimeter? Don't chuck the old HOT yet, it may be fine.

With a multimeter, check the resistance on that large white resistor on the back right corner that sticks straight up in the air. If that's good (the value is printed on the side of it), check all the diodes in that area. See if any of them are shorted out.

Then check the diode right beside where the yoke plugs in.

Then check the 1 or two large caps underneath the metal cover that the HOT bolts to. See if they're shorted from one side of the cap to the other, and then again if there's another one next to it.

Then check and see if the middle leg of the hot is shorted to the metal plate the HOT is mounted to.

When the monitor first comes on, do you hear it snap crackle and pop?

Let us know, we can get this sucker going!

I am positive the fuse is good.

The white resistor is good. I checked most of the diodes, but I'll see if there are some others I missed.

The middle leg is not shorted.

When the monitor turns on, there isn't any noise at all. The flyback makes no noise and there is no neck glow. The flyback is good.

I believe I checked those caps and everything checked out, but I can check again.
 
Last edited:
Securing the HOT to the heatsink without the insulator had to blow something open. If not the fuse then a trace or a resistor is open somewhere.

Matt
 
I would think that since the HOT was bolted to the heat sink like dude above said, you had a major 'short' when you powered it up, which would have blown the voltage regulator again.

Are you getting any b+ reading at all?
 
I will check that when I get home. Just in case, I will stop by the local electronic shop and pick one up if they have them. Can you remind me how to check the B+. When I tried before, I did the reading from the VR pin 4, and the voltage was alternating between 0 and 8V. If that doesn't sound right, I may have done something wrong in measuring. I haven't performed any electronic work since I was in high school, so I am basically starting all over in learning this.
 
Last edited:
Did you do all the continuity and solder checking I mentioned above. 9 out of 10 K7000's with good parts and no power are a direct result of this...
 
also dont forget to check the caps hear the shutdown pot to make sure they are the correct value( i believe they are 10 uf iirc)

a test of B+ would tell you for sure.
 
Either you're not reading it properly, or you have a major issue with the power section of your monitor chassis. Trace it in, through the fuse, through the diodes, through the VR, etc...
 
Back
Top Bottom