WG-19k7201 - No Power In Secondary

[Ohmerone]

well if you weren't going by my
Experience then it's
The only way to rule them
Out as suspects
That's failing under load is just replace them
The diode value is not good enough test
On these to know for sure.
Luk

 

[mk3u2012]

well if you weren't going by my
Experience then it's
The only way to rule them
Out as suspects
That's failing under load is just replace them
The diode value is not good enough test
On these to know for sure.
Luk

Very good.

Are there any substitutes for these specific part #'s FUF5407, MUR460? Looks like one of them is a high speed recovery diode. Do you know if these are common on other SMPS chassis? I hate waiting for shipping and have several parts chassis I could look at.

 

[Ohmerone]

Very good.

Are there any substitutes for these specific part #'s FUF5407, MUR460? Looks like one of them is a high speed recovery diode. Do you know if these are common on other SMPS chassis? I hate waiting for shipping and have several parts chassis I could look at.

I don't know atm
Have to match the numbers with other chassis
Just need to find known good ones
Since they are not obviously shorted
It's not a very common that the caps fail too
but there's a issue here.
with the diodes. Which one or both?

 

[mk3u2012]

Wanted to close this thread out by saying I know have a working k7201.

Huge thanks to @Ohmerone for troubleshooting the issue with me.

I blew the PWM a second time when I blew both main filter caps in the secondary. Swapped out both fast recovery diodes D101 and D101a, did a full cap kit and through in another PWM. Fired up and only have the expected 117vdc at D101.

Have some graphics/color issues to work out but I haven't even touched the main harness, filter board or CPU. So we shall work through that.

 

[Ohmerone]

Great!

Have you isolated the Video issue to the Monitor?

If so, Low screen voltage, or crt cathode voltage?
have you turned up the
Pot on the flyback? normal range?

did you make any changes with the caps you put
back from what you took out?
All soldered back in good?
Signal Good From game test video patterns.
Here's some things to check LUK.

 

[mk3u2012]

Great!

Have you isolated the Video issue to the Monitor?

If so, Low screen voltage, or crt cathode voltage?
have you turned up the
Pot on the flyback? normal range?

did you make any changes with the caps you put
back from what you took out?
All soldered back in good?
Signal Good From game test video patterns.
Here's some things to check LUK.

Video issue is with the boardset and not the monitor. I fixed the color issue and got the monitor to look pretty nice but the game board will need repair.

Everything seems to function as it should on the chassis.