monkey-pilot
New member
I recently installed a new flyback and cap-kit (from The Real Bob Roberts) for a GO7 Monitor. For about four days now, I have read just about anything and everything I have been able to locate regarding the issue I am having, and am running out of options:
It appears that all is working "OK" with the exception of the Horizontal Sync. The image will scroll, -The speed at which it travels will vary at times, and during those times that it is slow enough to notice, the characters are diagonal instead of "vertical" as I would expect.
The XO1 (H.O.T.), X301, X305 have been replaced (three times!!) with no change of results. I checked the values of R314, and R317. B+ is fine at 120V. I have not yet replaced IC501. Would it be worth changing? I am getting the feeling that I am replacing good parts with other good parts and not noticing any changes thus far.
Also, the Horizontal Frequency Pot was verified to be a 4.7K ohm range, cleaned, and replaced. It has a *very small range* that will provide an image which is not "garbled". This does not seem "normal" to me, and am wondering if I should replace the Pots on the back. When I say "small range", trust me... it sometimes seems that just breathing on the Horizontal Freq. Pot will make or break a discernible image!
Another thought that has occurred to me is the possibility that I have other components which may be missing and/or wrong values (from attempts to repair prior to me acquiring it) The schematics I have been using are very difficult to see with my poor eyesight.
One specific issue of confusion on my part is HOW should I "test" my H.O.T.??? One URL suggests that I use my DMM set to diode mode, and with the black clip connected to the HOT pin closest to the Flyback and the Red Lead on the other HOT pin, check for a voltage. I get Zero this way.. even with NEW parts!!! Another suggestion was to use the DMM the same way, but to clip the black lead to the chassis, and the Red lead touching the "case" of the HOT. This DOES produce a valid voltage range, although the monitor will still not sync Horizontally after I power up.
Please HELP!!!!! I am at my wits end here! I am reluctant to purchase (more) new parts, wait for them to arrive next week only to find there is still no change!
It appears that all is working "OK" with the exception of the Horizontal Sync. The image will scroll, -The speed at which it travels will vary at times, and during those times that it is slow enough to notice, the characters are diagonal instead of "vertical" as I would expect.
The XO1 (H.O.T.), X301, X305 have been replaced (three times!!) with no change of results. I checked the values of R314, and R317. B+ is fine at 120V. I have not yet replaced IC501. Would it be worth changing? I am getting the feeling that I am replacing good parts with other good parts and not noticing any changes thus far.
Also, the Horizontal Frequency Pot was verified to be a 4.7K ohm range, cleaned, and replaced. It has a *very small range* that will provide an image which is not "garbled". This does not seem "normal" to me, and am wondering if I should replace the Pots on the back. When I say "small range", trust me... it sometimes seems that just breathing on the Horizontal Freq. Pot will make or break a discernible image!
Another thought that has occurred to me is the possibility that I have other components which may be missing and/or wrong values (from attempts to repair prior to me acquiring it) The schematics I have been using are very difficult to see with my poor eyesight.
One specific issue of confusion on my part is HOW should I "test" my H.O.T.??? One URL suggests that I use my DMM set to diode mode, and with the black clip connected to the HOT pin closest to the Flyback and the Red Lead on the other HOT pin, check for a voltage. I get Zero this way.. even with NEW parts!!! Another suggestion was to use the DMM the same way, but to clip the black lead to the chassis, and the Red lead touching the "case" of the HOT. This DOES produce a valid voltage range, although the monitor will still not sync Horizontally after I power up.
Please HELP!!!!! I am at my wits end here! I am reluctant to purchase (more) new parts, wait for them to arrive next week only to find there is still no change!