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Main => Monitor/Video Forum => Topic started by: Q*Bert_OP on April 05, 2009, 09:51:27 pm

Title: Wells Gardner K7200 (can't lock vertical hold)
Post by: Q*Bert_OP on April 05, 2009, 09:51:27 pm
I have a Wells 13" K7200 that can't stop rolling vertically. I have Replaced all the caps and changed transistor Q7. I don't think IC2 could have gone bad. This monitor was NOS and kept in the box for 10 years, and saw about 1 year of use before this problem. I have also swapped remote PCBs with the same results, so I know the vertical hold pot isn't bad.
Title: Re: Wells Gardner K7200 (can't lock vertical hold)
Post by: ken_cinder on April 05, 2009, 10:29:04 pm
What is hooked up for sync? If it's Jamma composite, make sure it's only hooked up to the -H sync. Odd things can and do happen on these series of monitors if you don't.
Title: Re: Wells Gardner K7200 (can't lock vertical hold)
Post by: Q*Bert_OP on April 05, 2009, 10:44:04 pm
It's only on neg. horiz. sync.  :banghead:
Title: Re: Wells Gardner K7200 (can't lock vertical hold)
Post by: Kevin Mullins on April 06, 2009, 12:11:43 am
and saw about 1 year of use before this problem.

Was it working connected to the same game setup?
Title: Re: Wells Gardner K7200 (can't lock vertical hold)
Post by: Q*Bert_OP on April 06, 2009, 12:29:30 am
and saw about 1 year of use before this problem.

Was it working connected to the same game setup?

Yes, same setup. It's in a machine I sold about 1 year ago...the owner brought it back to me last week for service.
Title: Re: Wells Gardner K7200 (can't lock vertical hold)
Post by: ken_cinder on April 06, 2009, 12:46:31 am
Looking at the schematics here, possible it's as simple as a resistor on lines from the remote board input?

I'd check R131 and R64.