I have been contemplating rewinding it. I'll pull it apart and
see how bad. I Love the 250ma fuse mod. Im
thinking of some kind of fuse mod for this G08 im working on that keeps
blowing output transistors (yes they are the correct devices, not the
3716s). Ugh.
> I've thought about this some more, and it seems to me this would
not
> be that hard to rewind yourself. You can easily measure the turns
ratio
> of a working transformer with a signal generator set to the right
> frequency
> and a volt meter to read the output. Or just probe the input and
output
> terminals of the transformer in a working circuit, though the load
on the
> transformer could affect the readings.
>
> Then you could estimate the number of turns on the primary by
measuring
> the
> resistance of the wire and it's gauge, and using a chart that
lists the
> resistance/foot of the standard wire gauges.
>
> Winding transformers is not fun, but not hard to do. Just time
consuming.
> If there is enough demand, it might be worth while to get a batch of
them
> custom made.
>
> I know someone who sold a Scope Clock kit, and he had the special
> transformer
> he needed for his design custom made. I could ask him where he got
them
> made
> if there is enough interest to investigate this further.
>
> Is there a pent up demand for this transformer?
>
> ___
> Ken
>
>> --- k_lists@scrapheap.net wrote:
>>
>>
From: Ken Sumrall<k_lists@scrapheap.net>
>> To: vectorlist@vectorlist.org
>> Subject: Re: VECTOR: K6100 T901
>> Date: Sun, 28 Aug 2011 19:33:27 -0700
>>
>> I searched my local archives of the vector list, and found this
post
>> from July 8, 2007 from Hans O:
>>
>> > AH, now I remember. They're found in old B& W
raster chassis.
>> > Track down an old 19V1001 or 1003 chassis. Should be a
bunch of
>> > dead ones out there.
>> >
>> > Hans O
>>
>> Good luck!
>>
>> ___
>> Ken
>>
>> akswanson@ntelos.net wrote:
>>
>>> lol..no worries.. I guessed maybe I had the wrong part ##. I
will
>>> DEFINATLEY check that out!!
>>>
>>>
>>>
>>> > Oops, I just realized you're not talking about the
flyback, but
>>> the
>>> > smaller transformer on the HV board.
>>> >
>>> > Sorry, I don't know where to get a new one of
those. However, I do
>>> > recommend you read the installation manual for the
replacement
>>> flyback
>>> > which you can find at the first link below. It
includes
>>> instructions on
>>> > how to add 3 fuses to the HV circuit to protect
components
>>> (including
>>> > T901) in the event of another failure like the one you
have.
>>> >
>>> > ___
>>> > Ken
>>> >
>>> >
>>> > Ken Sumrall wrote:
>>> >
>>> >> You can get one here:
>>> >>
>>> >> http://www.cinelabs.com/wg6100/
>>> >>
>>> >> which has link to here:
>>> >>
>>> >> http://arcadeshop.com/wgxy-fb/wgxy-fb.htm
>>> >>
>>> >> $79, and comes with extra protection components and
a new focus
>>> >> assembly.
>>> >>
>>> >> Note, I've never ordered or used one of these
flybacks, I just
>> remmeber
>>> >> seeing it recently while searching for other parts
to bring a
>>> 6100
>> back
>>> >> to life.
>>> >>
>>> >> ___
>>> >> Ken
>>> >>
>>> >>
>>> >> akswanson@ntelos.net wrote:
>>> >>
>>> >>> I had suspected the triple nickel (555), and
indeed it was
>>> fried.
>>> >>> It also took out Q905, AND T901.. I verified
this by trying T901
>>> in a
>>> >>> known good HV unit. I got smoke, and another
blown Q905.. So if
>>> >>> anybody knows where I can get a replacement
T901 thatd be swell!
>>> >>>
>>> >>>
>>> >>>
>>> >>> > I'm not saying that you don't have
a bad T901, but can you
>>> verify
>>> >>> that
>>> >>> > IC901 (555 timer as a simple oscillator)
is running. A scope
>>> would
>>> >>> show a
>>> >>> > nice square wave coming out at pin 3. If
it is stuck in the
>>> high
>>> >>> state,
>>> >>> > it would keep Q904 and Q905 turned on
constantly and that
>>> would
>>> >>> certainly
>>> >>> > cause your problem. Of course in this
state, there would be
>>> no HV
>>> >>> output
>>> >>> > at all. Check ZD900 for 13V across it.
ZD900 is the voltage
>>> >>> regulator
>>> >>> > for the 555 chip. If the zener is
partially shorted and there
>>> isn't
>>> >>> > enough voltage across the 555 chip, then
the 555 chip output
>>> might
>>> >>> be
>>> >>> > stuck even if there's nothing wrong
with it. If the zener is
>>> >>> > open-circuit, the 555 chip will likely
have blown.
>>> >>> >
>>> >>> > You should remove R917 and leave it out
until you can verify
>>> that
>>> >>> IC901 is
>>> >>> > running okay and that the transistors
Q904/905 are both
>>> switching.
>>> >>> To
>>> >>> > functionally test Q905, you can add a
temporary 10k (to 47k)
>>> >>> resistor
>>> >>> > (1/2W to 1W) from +Vsupply (+28V) to Q905
collector. If scope
>>> shows
>>> >>> a
>>> >>> > good square wave, remove the temporary
resistor and return
>>> your
>>> >>> focus to
>>> >>> > T901.
>>> >>> > If you do not have a scope but you have a
voltmeter, connect
>>> your
>>> >>> meter
>>> >>> > (-) to ZD900 anode or IC901 pin 1. Use the
meter(+) to
>>> measure
>>> >>> voltage at
>>> >>> > ZD900 cathode and IC901 pin 8. Both should
be about 13V.
>>> Measure
>>> >>> IC901
>>> >>> > pin 3. If it is running, it should be
around 6.5V plus/minus
>>> around
>>> >>> 0.5V
>>> >>> > roughly. The point here is that pin 3
should be outputting a
>>> square
>>> >>> wave
>>> >>> > having roughly a 50% duty cycle so the
voltmeter should show
>>> >>> approximately
>>> >>> > one half the chip supply voltage.
>>> >>> >
>>> >>> >
>>> >>> > William Boucher
>>> >>> > http://www.biltronix.com
>>> >>> > ----- Original Message -----
>>> >>> >
>>> >>>
>>>
From: akswanson@ntelos.net
>>> >>> > To: vectorlist@vectorlist.org
>>> >>> > Sent: Sunday, August 28, 2011 9:20 AM
>>> >>> > Subject: VECTOR: K6100 T901
>>> >>> >
>>> >>> >
>>> >>> > One of my 6100s had a fire on the HV
board, took out R917 and
>>> Q905.
>>> >>> I
>>> >>> > replaced those, and got smoke again..
Comparing the
>>> resistance of
>>> >>> the
>>> >>> > primary of T901 to a known working T901 I
get 9.5 Ohms on the
>>> >>> suspected
>>> >>> > bad one and 17 ohms on the known good one.
I get the feeling
>>> I
>>> >>> melted
>>> >>> > the varnish on the wiring and shorted them
together.. Does
>>> anyone
>>> >>> know
>>> >>> > where (or have) and extra T901? Also, Is
there a secondary
>>> cause,
>>> >>> such
>>> >>> > as a flyback failure that would cause this
kind of failure? I
>>> dont
>>> >>> > want to blow the dang thing again..
>>> >>> >
>>> >>> >
>>> >>> >
>>> >>> > Andrew
>>> >>> >
>>> >>>
>>> >>
>>>
>>
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>>> >> chris@westnet.com
>>> >>
>>> >>
>>> >
>>>
>>
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>>> >
>>>
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Received on Fri Sep 2 20:40:47 2011
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