a loose screw

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Andy Le Blanc
Posts: 2582
Joined: Sat Dec 22, 2007 1:16 am
Location: central Maine

a loose screw

Post by Andy Le Blanc »

Had a crate "V" series across the bench with an interesting bent.

5212 VFX

The filter caps are grounded to the chassis through one of the pcb screws.
A washer over a couple jumper wires, if the thing comes loose the amp comes and goes.
I had to remove paint from the top of the mounting post and refresh a
bit of solder on the back of the pcb around the contact, and torque it good.

You have to remove the entire pcb the replace the pilot light, but it did have a nice OPT.
lazymaryamps
Jana
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Joined: Sun Sep 07, 2008 10:40 pm
Location: Minnesota

Re: a loose screw

Post by Jana »

I saw the thread title and I thought you were spreading rumors about me.
TheGimp
Posts: 195
Joined: Fri Oct 08, 2010 5:19 pm

Re: a loose screw

Post by TheGimp »

I miss-read the title as "A Screw Loose" and thought he was talking about me.
Andy Le Blanc
Posts: 2582
Joined: Sat Dec 22, 2007 1:16 am
Location: central Maine

Re: a loose screw

Post by Andy Le Blanc »

:lol:

Paranoid schizophrenic's have enemy's two.
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Ken Moon
Posts: 610
Joined: Tue May 08, 2007 2:41 pm
Location: Denver

Re: a loose screw

Post by Ken Moon »

Andy Le Blanc wrote: The filter caps are grounded to the chassis through one of the pcb screws.
Your experience shows exactly why this is such a bad practice - how much more expensive would it have been to add a dedicated ground bolt?

Lots of folks seem to like to connect ground wires to transformer mounting bolts, too - bad idea - just add a separate grounding bolt, and you'll never have to worry about it coming loose due to the torque on the transformer.
Andy Le Blanc
Posts: 2582
Joined: Sat Dec 22, 2007 1:16 am
Location: central Maine

Re: a loose screw

Post by Andy Le Blanc »

It was a surprise to me, I get tired of dealing with products designed for ease
of manufacture as the prime concern. It really is a bench fee just to change the pilot.
It's nice to have the features, but if you can't service the thing why bother with the investment.

I use a copper bus to a ul listed grounding block.
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Structo
Posts: 15446
Joined: Wed Oct 17, 2007 1:01 am
Location: Oregon

Re: a loose screw

Post by Structo »

Yeah but those $.03 ground screws add up.

Every 33 screws is another $1!

Bean counters can ruin any good product. :lol:
Tom

Don't let that smoke out!
TheGimp
Posts: 195
Joined: Fri Oct 08, 2010 5:19 pm

Re: a loose screw

Post by TheGimp »

I worked on a Traynor YMV-1 that would go red plate occasionally.

I finally realized it depended on whiich speaker jack was used. One had the ground wire soldered to it and the other three relied on mechanical ground through the barrel and nut (which had oxidized over the years).

I soldered new ground wires on the connectors and it hasn't had problems since then.

It is amazing the shortcuts compaines take in manufacturing.
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statorvane
Posts: 568
Joined: Thu May 11, 2006 3:28 pm
Location: Upstate New York

Re: a loose screw

Post by statorvane »

Bean counters can ruin any good product.
Tell me about it. My wife is a bean counter... :roll:
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