Re: Amplifone problems

If the resistor gets very hot, something is drawing more power than it
should draw. You could test if there are components on the board that are
out of spec, like the BU406D or the +24 V regulator.

You said you still have 19,5 KV HV? But the picture is still dim and out of
focus...

This would mean the other voltages (G1 (Screen) and G2 (Focus)) are probably
out of spec. Can you measure these (in respect to the DAG and the HV ground)

Another possible cause could be some grounding problem. If the ground to the
HV bourd would fall away, things like this will happen also.
Also a good tip is to add in-line fuses for the + and - 30 V Power Supply
wires going to the HV board (fast blow, 1 amp for the negative and 1.5 amp
for the positive supply) This way the fuse will blow in stead of burning up
the 5W resistors or worse, the Wintron.

I also saw about the same happening when the +30V is gone. Somehow the HV
boards keeps limping on the -30V supply giving all wrong tensions and thus a
fuzzy picture.

Mendel

----- Original Message -----
From: "Steven Winslow" <winslow@earthlink.net>
To: <vectorlist@vectorlist.org>
Sent: Monday, April 12, 2004 7:12 AM
Subject: Re: VECTOR: Amplifone problems

> Robb!
>
> Did you check the focus wire going to the focus block? It's hidden
> underneath the rubber boot. If this wire becomes disconnected (and they
do
> a lot) that one resistor will cook. I've had to resolder this wire more
> than once...
>
> Good Luck !
>
> Steve
>
>
> At 09:10 PM 4/11/2004 -0500, you wrote:
> >Hi again everyone, now that I'm done fussing with 6100's, it appears I
have
> >to do the same with a 19" Amp.
> >
> >I recently acquired a non-working Quantum in good shape, but not working.
> >The game played blind, and it had a red HVT in it, so I figured that was
> >likely problem #1. So I pulled the HV board out of my Star Wars UR and
put
> >it in the Quantum, and all was well. I ordered a Wintron to fix the
Quantum
> >HV board, and haven't gotten around to having it installed yet.
> >
> >Anyway, I pulled the HV board out of the Q a few days ago to do some work
on
> >my Star Wars. It was working fine. Put the board back in the Q
yesterday,
> >fired it up, and nothing. After a minute or so, I could see a very dim
and
> >very out of focus picture. So I reached around and turned up the
brightness
> >a bit, and it did get brighter, but it is still way out of focus, still
dim,
> >and I could see retrace lines. Also, the screen size wasn't right (the X
> >axis was way too big), aside from the fact that I had not done any
> >adjustments since the last time this board was in the Q.
> >
> >About this time I could sense the presence of that great burnt
"something"
> >smell, so I shut it down. Felt for warmth and the large resistor near
the
> >red can was VERY hot. It appears that both of those resistors were very
hot
> >at one time or another, but only that one was hot at this point.
> >
> >I haven't worked much on amplifones (yet), so I'm at a loss as to what to
> >try next. I've done some googling and also searched the vector list
> >archive, and didn't come up with much. Is this something common anyone
has
> >seen?
> >
> >Thanks for any help.
> >Robb Gonyer
> >
> >
> >
> >
>
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chris@westnet.com
>
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Received on Mon Apr 12 07:58:02 2004