[sdiy] OB8 power transformer

[Mike Bryant]

An intermittent shorted turn ?
________________________________
From: Synth-diy <synth-diy-bounces at synth-diy.org> on behalf of Michael E Caloroso via Synth-diy <synth-diy at synth-diy.org>
Sent: 27 May 2024 06:17
To: g m montalbano <montalbanogm at gmail.com>
Cc: synth-diy at synth-diy.org <synth-diy at synth-diy.org>
Subject: Re: [sdiy] OB8 power transformer

Voltage surge from lightning strike?

MC

On Sat, May 25, 2024 at 2:27 PM g m montalbano via Synth-diy <synth-diy at synth-diy.org<mailto:synth-diy at synth-diy.org>> wrote:
Yes, the one thing I don't want to hear from a customer is "I read it on the internet;  you should do ...."

HOWEVER, in this case, the customer was correct.  I finally got the OB8 on my bench, and the burnt smell (reminiscent of burnt resistor or opamp) is definitely coming from the transformer.  But, checking the transformer with a meter & scope reveals that all voltages are present and correct, and the transformer is running cool; all regulators are in good shape, and the 5V rectifier has been previously replaced with a higher rating.
The synth is playing perfectly.
My question is:  what burned on the transformer to create that smell, and why is it now working correctly?

On Tue, May 21, 2024 at 2:16 PM Gordonjcp <gordonjcp at gjcp.net<mailto:gordonjcp at gjcp.net>> wrote:
On Tue, May 21, 2024 at 03:26:36PM +0200, Roman Sowa via Synth-diy wrote:
> It doesn't necesarily be customer's view, but maybe something another tech
> told him before.

Which is why we have the plague of HERP DERP MUST REPLACE CAZAPITARS any time people get a faulty (or even just old but not faulty - yet!) piece of equipment.

--
Gordonjcp

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