Build Your Own Arcade Controls Forum

Main => Monitor/Video Forum => Topic started by: MK3FAN on May 19, 2009, 06:48:47 pm

Title: K7000 Not Powering Up
Post by: MK3FAN on May 19, 2009, 06:48:47 pm

Hey guys. I have a K7000 chassis. First it was blowing fuses. The HOT and the IC4 were shorted. Replaced both of them, now the chassis does nothing when powered up. I have 74VAC at the fuse. I tested all the pathways and reflowed all the solder points I compromised and it made no difference. I need help. Any ideas? If you need more info, let me know.

Title: Re: K7000 Not Powering Up
Post by: SirPeale on May 19, 2009, 09:32:37 pm

What do you have @ the power input?

Title: Re: K7000 Not Powering Up
Post by: Kevin Mullins on May 19, 2009, 09:55:01 pm

Quote from: MK3FAN on May 19, 2009, 06:48:47 pm

I have 74VAC at the fuse.

Is that from one of the mains inputs to the other? (which would be the fuse)

Title: Re: K7000 Not Powering Up
Post by: qrz on May 19, 2009, 09:57:44 pm

schematic here : http://www.wgec.com/pdf/Service/K7000.pdf

also check r103, c56, c57


qrz

Title: Re: K7000 Not Powering Up
Post by: MK3FAN on May 19, 2009, 10:09:38 pm

Thanks guys. Here are some stats. D19-D22 are good. The HOT is good. IC4 is good. R301 is good. R103 is OPEN. When I test for power, one lead is on chassis ground, the other is touching the component. I have 74VAC on both sides of the fuse and no 115VAC anywhere that it's supposed to be. I'll stick a new R103 in and see what happens.

Title: Re: K7000 Not Powering Up
Post by: MK3FAN on May 19, 2009, 11:24:59 pm

Fixed! Replaced R103 and it powered up. Only now, I have ridiculously bad images/picture. The flyback is making all kinds of weird noises and their is no red displayed. That's most likely one of the neckboard transistors, but I still have horizontal stretch issues, vertical stretch issues, color issues, it's really ridiculous. I'll start with a cap kit and a new flyback and see how much that helps. Thanks again guys. 

Title: Re: K7000 Not Powering Up
Post by: qrz on May 19, 2009, 11:38:52 pm

Quote from: MK3FAN on May 19, 2009, 10:09:38 pm

When I test for power, one lead is on chassis ground, the other is touching the component. I have 74VAC on both sides of the fuse and no 115VAC anywhere that it's supposed to be.

that is why the voltage is reading low .  u wish to measure the raw AC.  which,  is not referenced to chassis ground .
measure across the ac input to the rectifiers......
this is also a "hot chassis" requiring line isolation  ;)


qrz