I noticed most of this clone chassis have the spot for where the degauss pins should be, but there is nothing there. Is it possible to add degauss capabilities to this cheap chassis? I have quite a few!
I did salvage the electronics from the new old stock unit that got destroyed in the tornado, if that’s what you mean. Never used but it did spend days out in the yard.
Did you ever investigate more on this? I feel like with the availability and cost of original chassis now and how close to being a viable option these are, it's worth improving them as much as possible. When I finally get mine repaired (popped it with no iso and low ohm H on yoke) I plan to do some experimentation
Yeah, these can be quite handy at the price point, especially with some improvements. I didn't really experiment that much more because after this mod (I used even larger input caps later), I found this chassis to work pretty well. I just played that cab yesterday in fact, and It's still going strong.
I just had two new old stock WeiYa/Makvision monitors strewn across the yard in an EF-4 tornado. Both are ruined. You can see them in some of my aftermath footage. The one on the ground is a 38” and the other in the box is a 29”.
@@pcbjunkie1 Yeah. Some of my neighbors lost everything... not even a wall left standing. The chimney’s gone, the balcony is gone, most of the roof is gone, my car was crushed by a tree, etc but we still got extremely lucky considering the absolute devastation all around us. I don’t know what I would have done if the storm damaged a bunch of customer consoles or their equipment (lots of UltraHDMI HW2, PS1Digital, xStation, etc in the house).
Hi. Got a 27 year old Weche OK Baby arcade cabinet, 3 months ago, and it cames with one of this chasis (paired with a Videocolor monitor), curiosly signed, as the rest of the electronic parts of the machine, by Ying Tching Electronics, from Taiwan. No geometry issues, but same color issue as yours. Which capacitors would you recommend to replace the three indicated, as of today? Keep in mind that I am connecting a PC, not jamma boards. Thank you very much.
I have a problem with the weiya, the b+ is 140-145 volts and the b+ potentiometer doenst change anything, this generate a ondulation in the image and a burn Smell.
Awesome video, thanks for going into all this detail. I have two of these and they both have this color warping effect pretty terrible. Did you ever test out if shorting the leads helped further? If it helps at all I found that the effect lessens when I use lower voltage console RGB, and when I use buffered RGB (via retrotink Ultimate raspberry pi hat) the effect isn't there at all (or barely noticeable under extreme contrast differences with the other chassis). I'm definitely going to try those 220uf caps, hope to find a complete solution someday.
Yes it did, at least on the color fading problem. In the end i replaced the caps with 1000uF and the problem is mosly gone. I don't just want to remove those caps because I suspect they are there to possibly protect the source of the signal from being fed a DC offset from the chassis. Maybe this was their fix to stop things from blowing up if no isolation transformed is used. I honestly don't know. I looked a few schematics of Electrohome and Wells-Gardner chassis and I do not see AC coupling capacitors used in the input section so it's possible those caps are not needed at all under normal circumstances.
@@pcbjunkie1 Thanks for the reply. I noticed on mine they added a 1000uf cap in line with those coupling caps right before the signals go to the neckboard, and that 1000uf cap would blow after a few hours of operation every time (I went through quite a few), until I changed the coupling caps to higher capacitance. I honestly have no faith in these boards but it's good to have one on hand in a pinch.
@@pcbjunkie1 Yeah on both of them, even though one has a 120-220v power supply with its own transformer on it. Different layout but the same basic circuit it looks like, same coupling caps and all that, same issues. The only arcade boards I have to test them with are a few MVS boards, and I read that those output hotter RGB than most, and I only have consumer TV tubes also, so that might be contributing to the problem (they match impedance ratings but I have an LCR meter coming to test inductance too).
Hi pcbjunkie I bought a new universal arcade chassis awhile back a C2729 and the corners are warped on a flat screen tube, I managed to find an older rounded tube with the right yolk readings and its seems to be abit less noticable but still there especially pronounced on side scrolling games any idea why? or if how to fix it?
There is a pincushion adjustment on these. It's one of the knobs. On mine the max adjustment just barely makes the image straight. I never messed around with this section so I don't know what components are responsible. Sorry about that.
nice video, how to adjust contrast on this chassis, when i load up the game i have gray screenn it should be black, when i turn flyback down to get black the picture go to dark
I don't remember if there is a contrast knob (I think there is) but you can also increase the gain (3 rgb pots near the input connector), and then use the pots on the CRT neck board for the cutoff to darken blacks. It's easier if you have a video signal generator and know what the colors should look like.
There are clones for 20 inch tubes. Since they are adjustable, I'm guessing they should also work with a 19" tube. Mind you I haven't tried them, so I don't know if they are any good.
I have a weiya h425 its like the same of these you show, with green screen problem and horizontal line in the center, i changed the resistor 140ohms to a 160ohms also the capacitors 330uf to a 470uf but i also have the same problem, maybe change the diodes 10bb4t to fr205 that i read these fail?
@@pcbjunkie1 i changed it too, maybe i break it with some voltage i am going to change it again, Also do you think that the resistor r401 have to be less than 3.3k and the r409? thanks for your message I appreciate your comment
🤔good info!!! 👍🏻
Great job! Thanks for the info and the troubleshooting.
I noticed most of this clone chassis have the spot for where the degauss pins should be, but there is nothing there. Is it possible to add degauss capabilities to this cheap chassis? I have quite a few!
I think that changing the C101 220uf capacitor that stabilizes the 3 transistor bias with a larger one i.e. 470uf will help with the problem.
Yeah I can’t adjust the horizontal size much. Maybe I should change the width cap
Man I wish they would make a tri sync chassis replacement. It's getting really hard to find replacements.
I did salvage the electronics from the new old stock unit that got destroyed in the tornado, if that’s what you mean. Never used but it did spend days out in the yard.
Did you ever investigate more on this? I feel like with the availability and cost of original chassis now and how close to being a viable option these are, it's worth improving them as much as possible. When I finally get mine repaired (popped it with no iso and low ohm H on yoke) I plan to do some experimentation
Yeah, these can be quite handy at the price point, especially with some improvements. I didn't really experiment that much more because after this mod (I used even larger input caps later), I found this chassis to work pretty well. I just played that cab yesterday in fact, and It's still going strong.
@pcbjunkie Great! Did you go with 470uf? I may at some point make a schematic to make maintenance easier
Well done. Thank you for documenting this.
I just had two new old stock WeiYa/Makvision monitors strewn across the yard in an EF-4 tornado. Both are ruined. You can see them in some of my aftermath footage. The one on the ground is a 38” and the other in the box is a 29”.
Oh dude, that sucks. House still standing, but all the finish wrecked. Lots to repair... Sorry to hear.
@@pcbjunkie1 Yeah. Some of my neighbors lost everything... not even a wall left standing. The chimney’s gone, the balcony is gone, most of the roof is gone, my car was crushed by a tree, etc but we still got extremely lucky considering the absolute devastation all around us. I don’t know what I would have done if the storm damaged a bunch of customer consoles or their equipment (lots of UltraHDMI HW2, PS1Digital, xStation, etc in the house).
F
@@justz00t48 ?
@@emmettturner9452 Paying respects for your loss.
I was looking at getting one of those universal chassis to replace a busted D9400. I can't get an answer telling me if it would work or not.
Me too let me know if you find anything out
@@brentlacouture9994 hey you got a d9400 also?
Hi. Got a 27 year old Weche OK Baby arcade cabinet, 3 months ago, and it cames with one of this chasis (paired with a Videocolor monitor), curiosly signed, as the rest of the electronic parts of the machine, by Ying Tching Electronics, from Taiwan. No geometry issues, but same color issue as yours. Which capacitors would you recommend to replace the three indicated, as of today? Keep in mind that I am connecting a PC, not jamma boards. Thank you very much.
I have a problem with the weiya, the b+ is 140-145 volts and the b+ potentiometer doenst change anything, this generate a ondulation in the image and a burn Smell.
Sweet video tude; arcade's Louis Rossman here folks!
I might be mistaken, but I think on a K7000 the equivalent colour capacitors are bi-polar.
Awesome video, thanks for going into all this detail. I have two of these and they both have this color warping effect pretty terrible. Did you ever test out if shorting the leads helped further? If it helps at all I found that the effect lessens when I use lower voltage console RGB, and when I use buffered RGB (via retrotink Ultimate raspberry pi hat) the effect isn't there at all (or barely noticeable under extreme contrast differences with the other chassis). I'm definitely going to try those 220uf caps, hope to find a complete solution someday.
Yes it did, at least on the color fading problem. In the end i replaced the caps with 1000uF and the problem is mosly gone. I don't just want to remove those caps because I suspect they are there to possibly protect the source of the signal from being fed a DC offset from the chassis. Maybe this was their fix to stop things from blowing up if no isolation transformed is used. I honestly don't know. I looked a few schematics of Electrohome and Wells-Gardner chassis and I do not see AC coupling capacitors used in the input section so it's possible those caps are not needed at all under normal circumstances.
@@pcbjunkie1 Thanks for the reply. I noticed on mine they added a 1000uf cap in line with those coupling caps right before the signals go to the neckboard, and that 1000uf cap would blow after a few hours of operation every time (I went through quite a few), until I changed the coupling caps to higher capacitance. I honestly have no faith in these boards but it's good to have one on hand in a pinch.
@@old_and_obsolete Are you using an isolation transformer?
@@pcbjunkie1 Yeah on both of them, even though one has a 120-220v power supply with its own transformer on it. Different layout but the same basic circuit it looks like, same coupling caps and all that, same issues. The only arcade boards I have to test them with are a few MVS boards, and I read that those output hotter RGB than most, and I only have consumer TV tubes also, so that might be contributing to the problem (they match impedance ratings but I have an LCR meter coming to test inductance too).
@@pcbjunkie1 A follow up video would be great to see the difference, got one on order so would be interesting to see
Hi pcbjunkie I bought a new universal arcade chassis awhile back a C2729 and the corners are warped on a flat screen tube, I managed to find an older rounded tube with the right yolk readings and its seems to be abit less noticable but still there especially pronounced on side scrolling games any idea why? or if how to fix it?
There is a pincushion adjustment on these. It's one of the knobs. On mine the max adjustment just barely makes the image straight. I never messed around with this section so I don't know what components are responsible. Sorry about that.
nice video, how to adjust contrast on this chassis, when i load up the game i have gray screenn it should be black, when i turn flyback down to get black the picture go to dark
I don't remember if there is a contrast knob (I think there is) but you can also increase the gain (3 rgb pots near the input connector), and then use the pots on the CRT neck board for the cutoff to darken blacks. It's easier if you have a video signal generator and know what the colors should look like.
@@pcbjunkie1 thanks for info, The châssis don’t have contrast pot, I think I have to play with RGB pot
@@pcbjunkie1 i shorted that 3 capacitor, the color and contrast are insanely good, I’m so happy with the results, thanks man
Is there one of these universal chassis that would fit a 19" tube?
There are clones for 20 inch tubes. Since they are adjustable, I'm guessing they should also work with a 19" tube. Mind you I haven't tried them, so I don't know if they are any good.
I have a weiya h425 its like the same of these you show, with green screen problem and horizontal line in the center, i changed the resistor 140ohms to a 160ohms also the capacitors 330uf to a 470uf but i also have the same problem, maybe change the diodes 10bb4t to fr205 that i read these fail?
It's probably the vertical deflection chip TAxxxx. I had mine fail too. I think that heatsink may be too small for it.
@@pcbjunkie1 i changed it too, maybe i break it with some voltage i am going to change it again, Also do you think that the resistor r401 have to be less than 3.3k and the r409? thanks for your message I appreciate your comment
You’re splitting hairs man