RE: Ampliphone HV blowing +24v reg (fwd)

I've been having trouble with a board blowing the +24 and BU. The MC1, T1,
and HVT are known good on mine. The clock circuit and amplifiers are working
fine. So, it may be Q5 that is bad.

I was working on another HV board recently where Q5 went up in smoke. I took
it off the board and it works great now. Of course I need to repair the
overvoltage circuit now, but it will work without Q5. Removing Q5 completely
disables the overvoltage.

JB

-----Original Message-----
From: Bret Pehrson [mailto:bret@infowest.com]
Sent: Sunday, January 05, 2003 9:27 PM
To: vectorlist@synthcom.com
Subject: RE: VECTOR: Ampliphone HV blowing +24v reg (fwd)

I can't remember exactly which reg, but I had a bad BU406D that was blowing
mine. Replaced it along w/ a new reg and was up and running.

> -----Original Message-----
> From: owner-vectorlist@synthcom.com
> [mailto:owner-vectorlist@synthcom.com] On Behalf Of
> Christopher X. Candreva
> Sent: Sunday, January 5, 2003 6:18 PM
> To: vectorlist@synthcom.com
> Subject: VECTOR: Ampliphone HV blowing +24v reg (fwd)
>
>
>
>
> I posted this last night, but I don't think I ever saw it
> show up on the
> list:
>
>
>
> My Ampliphone HV just started blowing the +24v reg. This is
> rebuilt as per
> the FAQ, so it's blowing open a 7824CV. Since it's obviously
> not going to
> be working in time for the 6:00 PM party I'm having, I'm posting.
>
> Thw FAQ says to check for:
>
> make sure rev MCI can is clear of the 5w 50 ohm resistor (it is)
>
> Inspect MCI case for cracks burns (don't see any)
>
> Try replaceing the MCI (I don't have a spare, but an
> replacement ws
> posted to the list)
>
> Check sener diode 1N754A (checked OK)
>
> Is there a way to test the MCI can ? Anything easy to check
> before going
> into full analysis mode ?
>
> -Chris
>
> ==========================================================
> Chris Candreva -- chris@westnet.com -- (914) 967-7816 WestNet
> Internet Services of Westchester http://www.westnet.com/
> --------------------------------------------------------------
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>
>

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Received on Mon Jan 6 05:55:49 2003