Re: K6100 T901

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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Received on Sun Aug 28 22:24:36 2011