Re: Re: Unusual WG6100 Deflection Board Problem

  I vote for cracked traces like Mark suggested. They can be tricky to
see as they are typically hairline, those neck PCB's can be brittle
after all these years baking. Get out the voltmeter (DC since it is
rectified) or Oscope (15Khz AC) and measure back from the pins on the
neckboard to the source components (D108), it will disappear and then
re-appear somewhere... your problem is between those two points.

On 3/24/2011 12:32 PM, Cinelabs Info wrote:
> If you know the tube is good, and, you know the neck board is good,
> then why did you ask about troubleshooting the "downstream end of the
> heater circuit"? I'm not sure I follow your logic.
> So, given:
> A) Tube is good
> B) Neck board, including CRT socket and CRT is good
> C) Voltage on D108 is good
> and you're complaining of:
> D) Originally, no picture ("no Z signal")
> E) Now, no heater
> I go back to my original suggestion from several days ago; have you
> double checked that the individual wires (black, brown and wht) and on
> the _correct_ terminals on the def pcb?
> Are there cracked solder joints around said terminals (on def pcb)?
> ---
> To verify the neck board, socket and CRT heater, remove the black and
> brown wires from the def pcb, and measure the resistance between them.
> Report what you find.
> -Mark
>
>
> On Thu, Mar 24, 2011 at 1:04 PM, Malcolm Mackenzie
> <maxstang@sbcglobal.net <mailto:maxstang@sbcglobal.net>> wrote:
>
> Thanks for responding Mark. Tube is good and displays a bright
> pic with two different alternate deflection boards. I didn't test
> the filament resistance.
>
> --- On *Thu, 3/24/11, Mark Shostak /<shostakmark@gmail.com
> <mailto:shostakmark@gmail.com>>/* wrote:
>
>
> From: Mark Shostak <shostakmark@gmail.com
> <mailto:shostakmark@gmail.com>>
> Subject: Re: VECTOR: Re: Unusual WG6100 Deflection Board Problem
> To: vectorlist@vectorlist.org <mailto:vectorlist@vectorlist.org>
> Date: Thursday, March 24, 2011, 9:19 AM
>
>
> What's the filament resistance reading (measured directly
> across the pins on the kine)?
>
> Is there continuity between the neck board and the kine pins?
>
> Did you try to rejuvenate the tube?
>
> -Mark
>
> On Thu, Mar 24, 2011 at 11:08 AM, Malcolm Mackenzie
> <maxstang@sbcglobal.net
> <http://mc/compose?to=maxstang@sbcglobal.net>> wrote:
>
> Ok...I've looked into this further and I'm even more
> perplexed. It appears the heater circuit isn't working.
> R107 on the deflection board never gets warm. I've got AC
> coming in to D108 and DC (-10V) coming out of D108 and the
> same voltage measured at the neck board where it enters
> the socket for the tube heater. Keep in mind that this
> neck board and tube work fine with another deflection
> board. Anyone good enough with schematics to tell me what
> to look for on the down stream end of the heater circuit?
>
> --- On *Sat, 3/19/11, Malcolm Mackenzie
> /<maxstang@sbcglobal.net
> <http://mc/compose?to=maxstang@sbcglobal.net>>/* wrote:
>
>
> From: Malcolm Mackenzie <maxstang@sbcglobal.net
> <http://mc/compose?to=maxstang@sbcglobal.net>>
> Subject: Unusual WG6100 Deflection Board Problem
> To: "Vector List" <vectorlist@vectorlist.org
> <http://mc/compose?to=vectorlist@vectorlist.org>>
> Date: Saturday, March 19, 2011, 7:53 AM
>
> Hey guys. I've rebuilt a few 6100 deflection boards,
> including the one I'm currently having a problem
> with. I rebuilt the low voltage section and it worked
> fine, so I put it in my spares pile. Just pulled it
> out and I'm getting no video. I hear deflection
> chatter, I have the correct voltages on pins 1/8 and 5
> of P900, but no video. It's almost like I'm getting
> no Z output. Anyone with greater knowledge than I
> have an idea? The rest of the monitor tests good with
> another deflection board.
>
>
>

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Received on Thu Mar 24 17:15:28 2011