Re: G05 issue

I replaced R602 even though it seemed ok, but still had the same issue. I checked B+/- and both are at 39v. There is a fair amount of ac on those lines (.3mV if I recall correctly from yesterday) so I replaced both the 6800 caps with new ones. No difference in the AC ripple, or the image. All other caps are new as well. I did find out though, that if I adjust R602 and R601 (think that is the other Y pot) down to their minimum, that the image is fine if it is squished into a band in the center of the screen that does not include that 1/4-1/3 band along the bottom of the crt. As soon as the image enters that area, it starts to vibrate and gets distorted. - I put in another known working deflection and the image is great, so its not a crt or HV issue. - I again re-soldered all the connector posts, pushing them all down a couple mm into the pcb so I for sure had a post on the opposite side that was soldered well. - The bad deflection also seems to be bright on startup. What I mean is I can adjust it so the bright/contrast is good for omega race with the 2 intensities. But if I turn the cab off and on, it seems the bright vectors are too bright again, and the lower ones quite dim. I did check everything in the guide that mentions vectors being too bright and all was ok. Heater voltage I adjusted right onto 6v and it is steady.   thanks From: "wboucher6_at_cogeco.ca" <wboucher6_at_cogeco.ca> To: vectorlist_at_vectorlist.org Sent: Tuesday, February 21, 2012 5:07:28 PM Subject: re: VECTOR: G05 issue Sounds like R602 pot is misadjusted or broken.  The input clamping circuit may be limiting Y. Another possibility, check the positive and negative DC supply levels B+ and B-.  One of those rails may be too low. The one to check is indicated by which half of the screen has the problem.  I forget off the top of my head which is which or I'd just say. Bill Boucher http://www.biltronix.com > > > I had a similar isse back in 2008 with a g05, but I don't have a clue what the solution was. Well fast forward to > today and I have a new battlezone basketcase I just got. The deflection was in bad shape. I recapped everything, new > side transistors, and went to work on verifying all else as the monitor just would not function in any respect. One of > the connectors had the metal posts come off the pcb. So the guy soldered wire on the underside to join the bottom of > the posts to positions on the pcb. The wiring is done correctly and should work. A couple of the posts were not > completely through the pcb and had lost some contact so I melted the solder, and pushed the posts through the pcb so I > could fasten them a lot better. After all of this, the monitor now finally works, but I have the same issue as below, > only it is the bottom that is compressed. Its maybe 1/4 to 1/3 of the bottom of the screen that is compressed into a > line that vibrates much like a >  loose connection would cause.. but I have verified all the connector posts for continuity. The top 3/4-2/3 of the > screen is rendered absolutely fine. Is there anything other than a connector issue that could cause this?   > ---------------------------------original post 2008------------------------------------ > This monitor was working fine, then a bunch of resistors in the Y section fried after a 3906 died. I replaced all the > burnt resistors, the 3906 and tested every other transistor and diode..all were fine. Put deflection back in and only > got a thin line across the center horizontally.. threw in another deflection and it worked, so HV and frame > transistors were good.. Well after pulling out my hair, went through every resistor and found the large 2ohm wirewound > one in the Y was in the meg-ohms.. something must have happened to it.. so swapped out with another one, and it looked > like the monitor was working when I fired up Omega Race..until the text wrote out to full screen.. I still have an > issue.. When something is displayed over the whole screen, I have about the top 1/3 compressed into a horizontal > line..but the rest is fine. It is more than half the screen as the center box in Omega Race is complete..another inch > or two above that box is where it   compresses... I've verified pretty well everything I can on that side of the > deflection.. does this point to anything I can maybe re-check? > --------------------------------------------------------------------------- ** Unsubscribe, subscribe, or view the archives at http://www.vectorlist.org ** Please direct other questions, comments, or problems to chris_at_westnet.com
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Received on Sat Feb 25 11:34:42 2012