Re: G05-801 Tech

Any rectifier of similar specs to or better than those Varo VG2X will
work in that 400VDC power supply circuit.

utahtaper wrote:
> It would appear that the D901 and D902 VG 2X rectifiers are open.
> Anyone know of a common vendor to grab these from?
>
> ----- Original Message -----
> *From:* utahtaper <mailto:utahtaper@comcast.net>
> *To:* vectorlist@vectorlist.org <mailto:vectorlist@vectorlist.org>
> *Sent:* Friday, May 01, 2009 9:34 PM
> *Subject:* Re: VECTOR: G05-801 Tech
>
> Thanks for answering my post guys. I really appreciate the lengthy
> write up Mark! I checked all of the stuff you suggested and
> everything looked within range. So in the agony of defeat I
> grabbed a G05-802 HV cage and threw it in the 801 and it's running
> perfect. So I can assume the problem lies within the HV cage. Any
> ideas what in the HV cage might cause the things I described?
>
> ----- Original Message -----
> *From:* Cinelabs Info <mailto:cinelabs.info@gmail.com>
> *To:* vectorlist@vectorlist.org
> <mailto:vectorlist@vectorlist.org>
> *Sent:* Friday, May 01, 2009 12:30 AM
> *Subject:* Re: VECTOR: G05-801 Tech
>
> Jason,
>
> Your complaint about retrace that can't be adjusted out
> indicates you have a voltage wrong (somewhere). Since you
> didn't mention a focus problem, it's most likely on G1 and/or
> the cathode. Both of these are derived from your +90V supply,
> so that's a prime candidate. Regardless, check all of your
> voltage supplies.
>
> Your complaint about a spot after power down indicates the
> grid and cathode are losing potential too quickly (relative to
> the crt cooling down). This also supports the low +90V supply
> theory.
>
> D509 and C506 are intended to suppress "the spot" after power
> down. If you replaced C506 when you capped the monitor, you
> may have installed a defective part, an incorrect part, or the
> part may have been installed incorrectly. You didn't mention
> if the symptom was present before you capped it, but that
> would be a good indicator.
>
> If your +90V supply is good, check the voltage across C506. It
> should be very close to whatever voltage you measured on the
> 90V rail. If it's not, C506 or D509 may be defective.
>
> One other note. The spot on the screen remains until the
> heater in the CRT cools down, which is around a minute. The
> "voltage in the tube" can remain for a much longer period of
> hours or even days or more. C506 is used to ensure sufficient
> voltage to pinch off the beam, is present for at least as long
> as it takes the heater to cool.
>
> HTH. Let us know what you find.
>
> Thanks,
> -Mark
> On Thu, Apr 30, 2009 at 9:50 PM, utahtaper
> <utahtaper@comcast.net <mailto:utahtaper@comcast.net>> wrote:
>
> I'm debugging an 801. Monitor has been capped and
> bottlecaps replaced. The monitor fully works however there
> is always a dot right in the middle of the screen(Like a
> spot killer dot) not a bright dot, but a dot none the
> less. The dot is even still there when the brightness and
> contrast are turned all the way down. Never ran across
> this one before. Anyone seen this before and have some
> suggestions?
> The dot is also there when the game turns off and slowly
> disappears as the voltage in the tube drops. Or if I bleed
> it off myself with my probe.
> Thanks in advance!
> Jason
>
>

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Received on Sat May 2 10:59:02 2009