23-01-2012, 10:58 PM
Hi Rob.
First, let me say that I am not totally familiar with that particular 'scope: all my comments are of a generic nature, based on the general principles of 'scope design, operation - and my general experience. But I notice your reference to 'plug-in modules'. Now bearing in mind your earlier fault report and your comment about lack of use of this 'scope, and knowing how contact surfaces of the 'wipe-to-connect' plug 'n' socket style of connector become easily tarnished with lack of use, I now suspect that that is where the original fault was / is. Very briefly, the contact areas should always be bright 'n' shiny. Often several 'plug-in' / 'plug out' operations scrape sufficient tarnish away to produce a sufficient low-resistance contact on the pins. (Same argument applies to rotary switches and valve pins and their sockets). Bear in mind that the currents across the plug/socket connectors will usually be very low - and typically only of the order of a few mA in the case of PSU currents; far, far less for signal currents. A little bit of tarnish can easily introduce sufficient resistance to stop things working . . . and maybe intermittently . . .
As with all electronic products, provided the basic electronic design is 'sensible' and quality components have been used, it is then often the 'mechanics' that cause trouble - especially if dampness, humidity, wide ranges of temperature have been manifest.
Al.
First, let me say that I am not totally familiar with that particular 'scope: all my comments are of a generic nature, based on the general principles of 'scope design, operation - and my general experience. But I notice your reference to 'plug-in modules'. Now bearing in mind your earlier fault report and your comment about lack of use of this 'scope, and knowing how contact surfaces of the 'wipe-to-connect' plug 'n' socket style of connector become easily tarnished with lack of use, I now suspect that that is where the original fault was / is. Very briefly, the contact areas should always be bright 'n' shiny. Often several 'plug-in' / 'plug out' operations scrape sufficient tarnish away to produce a sufficient low-resistance contact on the pins. (Same argument applies to rotary switches and valve pins and their sockets). Bear in mind that the currents across the plug/socket connectors will usually be very low - and typically only of the order of a few mA in the case of PSU currents; far, far less for signal currents. A little bit of tarnish can easily introduce sufficient resistance to stop things working . . . and maybe intermittently . . .
As with all electronic products, provided the basic electronic design is 'sensible' and quality components have been used, it is then often the 'mechanics' that cause trouble - especially if dampness, humidity, wide ranges of temperature have been manifest.
Al.
