dbstallman
Member
About a year ago, my 25" WG K7000 went black. I had never worked on a monitor before and was rather terrified of the high voltages. But after steeling my courage, I decided I could make it work and talked to some other people at auctions who gave me suggestions as to what the issue could be from my description of the problems before it went out.
I went to Bob Roberts and ordered a replacement cap kit, flyback transformer and horizontal width coil. I took the chassis off and found that the fuse had blown. Since it was apart, I installed all my parts, replaced the fuse and put it back together. The fuse promptly blew again. I then replaced the HOT and the Voltage regulator (2 times each!) but the fuses kept blowing. Many months went by and about 3 weeks ago, I decided to try and tackle it again. I saw a suggestion to someone with a similar problem to check the Crit Safety Cap (C36) for short, which mine was. After replacing that and C38 (also shorted), the monitor fired up.
Now that you know the history, here are my new problems :
Horizontal width will not adjust to fill the screen. I have adjusted the coil all the way, but it gets to a max of about 60%.
The B+ voltage is 150~154 on one side of the 220 ohm resistor and 115 volts on the other.
The tube goes dark after being on about 20 mins., but will turn back on for about 4 mins. after a 1 minute rest and a full 20 mins. again after a 30 minute rest.
I've checked Randy Fromm's flowchart and it says the problem should be my voltage regulator. I swapped it out and there was no change to the voltages. Both VR's check good on my meter.
Anyone have any good ideas where to look next?
Thanks.
I went to Bob Roberts and ordered a replacement cap kit, flyback transformer and horizontal width coil. I took the chassis off and found that the fuse had blown. Since it was apart, I installed all my parts, replaced the fuse and put it back together. The fuse promptly blew again. I then replaced the HOT and the Voltage regulator (2 times each!) but the fuses kept blowing. Many months went by and about 3 weeks ago, I decided to try and tackle it again. I saw a suggestion to someone with a similar problem to check the Crit Safety Cap (C36) for short, which mine was. After replacing that and C38 (also shorted), the monitor fired up.
Now that you know the history, here are my new problems :
Horizontal width will not adjust to fill the screen. I have adjusted the coil all the way, but it gets to a max of about 60%.
The B+ voltage is 150~154 on one side of the 220 ohm resistor and 115 volts on the other.
The tube goes dark after being on about 20 mins., but will turn back on for about 4 mins. after a 1 minute rest and a full 20 mins. again after a 30 minute rest.
I've checked Randy Fromm's flowchart and it says the problem should be my voltage regulator. I swapped it out and there was no change to the voltages. Both VR's check good on my meter.
Anyone have any good ideas where to look next?
Thanks.