Hello, I was wondering if anybody could help me. I was watching the Masters when my marquee lamps went out and then they come back on for 1 sec, then go back off for 3 secs and back on for 1 sec....on and off automatically by itself.

I powered the unit off, no change. I unplugged the unit and turned it back on and no change. It stills behaves the same. Do I have a bad power supply?

Thanks for any input.

When the image comes back, does it 'drift' back into place, being too large for the screen and out of focus, and then comes to fit the screen and in focus? If so, then you have HV shutdown issues. Either the HVPS is bad, or you have an HV arc somewhere that is causing HV shutdown. Other issues such as a bad neck card or a bad HDM can also cause intermittent HV shutdowns, but they usually don't cycle the way you describe.

[QUOTE=vavadie
Do I have a bad power supply?

Thanks for any input.[/QUOTE]

Like Curt said....

Likely.

One question, is your physical setup poor ? Do you have to use LOTS of adjustment on virtually ALL of your geometry settings to overcome too great a projection angle or an off center setup ?

I ask because I knew a fellow who had a Marquee that ATE HVPS's, until he corrected a very, very poor physical setup, when that was done, and geometry settings were minimized, the destruction of HVPS's ended....

well, I went to power up to answer your questions and now it works. I will find out tomorrow to see how long it lasts.

Before hand, the picture opens up to span the screen size and after my post I did time it again more accurately to 6 secs = no pic to 1 sec = pic.

Good point None, I will look into it.

When the image comes back, does it 'drift' back into place, being too large for the screen and out of focus, and then comes to fit the screen and in focus? If so, then you have HV shutdown issues. Either the HVPS is bad, or you have an HV arc somewhere that is causing HV shutdown. Other issues such as a bad neck card or a bad HDM can also cause intermittent HV shutdowns, but they usually don't cycle the way you describe.

Yes, it only lasted an hour and went back into the shut down issues you've described above, Curt.
What part do I need to replace?

Yes, it only lasted an hour and went back into the shut down issues you've described above, Curt.



I found this Technical Bulletin about the Contrast Setting.

Re: The Projected Image May Disappear on Marquee Projectors Set to High
Contrast Levels Depending on the Image Content

Applies to: Marquee 8000 and 9000 series projectors

Symptoms: The projected image disappears and then reappears larger and de-
focused. It then shrinks to the proper size and focus. The
disappearance and reappearance of the image may cycle continuously
or may only occur occasionally. This behavior is due to the high
voltage/CRT protection circuitry being tripped inadvertently, shutting
down the High Voltage module output. The re-focusing and shrinking
image size are the observable effects of the High Voltage turning back on
and increasing up to its regulated voltage. This effect is normal (not a
fault) when the projector is first turned on. The protection circuitry can be
tripped if there is a vertical or horizontal deflection failure or if the amount
of CRT current in any one of the CRTs exceeds the safety limit for X-ray
emissions. Normally, circuitry on the VNB detects the current within
each CRT and then circuitry on the Video Input Module (VIM) limits the
amount of current by automatically limiting the effects of the contrast
adjustment. Under specific circumstances, the problematic symptoms
described above may occur. These circumstances are related to image
content and are:
1. The Contrast setting is high (usually greater than 80%)
2. The HFAIL or VFAIL LED's on the control Module do
not light
3. (a) The Projected image has a large bright area
encompassing about 25% of the image with the rest of
the image being much darker
and/or
3. (b) The projected image changes abruptly from a very dark
scene to a very bright scene (as may occur when playing
a videotape)

Cause: What has been happening is that a shortcoming in the design of the
limiting circuitry on the VIM has become apparent. This has allowed
the current to exceed the specified limit enabling the protection
circuitry thereby shutting down the High Voltage output. The cycling
effect occurs because once the High Voltage output is shut off, the current
is also shut off and the limit is then not exceeded and so the protection

continued...2
circuitry recovers, only to be enabled once again when the High Voltage
turns back on. When confirming this particular problem, make sure
that the HFAIL or VFAIL LED's on the control module do not come
on. If they do, this is an indication that the High Voltage shutdown
has been initiated by a deflection failure. See also TBC94-3.

Action: Turning down the contrast or brightness will reduce the incidence of
protection circuitry enabling and the associated High Voltage shut down
with its undesirable visual effects. This may be an acceptable short term
solution. As a complete solution, qualified service personnel are
welcome to perform the following modifications to the Video Input
Module (VIM).

1. Replace C98, C99, C100, C94, C106, C107 (all six capacitors are
1uF, 50V) with 10uF, 16V tantalum surface mount (SM) capacitors
only (Electrohome part number 85-141303-03P). Be sure to observe
polarity markings. Do not use electrolytic capacitors (since they have a
higher leakage current specification than is required).

2. Lift one leg of C97 (680nF, 50V) and solder in series with it, the
parallel combination of a 68nF capacitor and a 56Kohm resistor. Solder
the other end of the resistor/capacitor combination into the solder hole
left after lifting the leg of C97. See the drawing for clarification.

3. Replace R213, R216, R217 ( all three are 475 kohm, SM) with three
220 kohm resistors. The replacement 220 kohm resistors need not be
SM parts.

R217
R216 R213

C100
C99
C98
C107
C106
C94
+ + +
+ + +

C97


Add 56 kohm Resistor
Add 68 nF Capacitor





page 1
Date: September 1994 File No. TBC94-11

Technical Bulletin

Hello

Old bulletin, not likely applicable unless old boards in your Marquee.