[Pamphonica]

I have been fault-finding an Avo 8 Mk5. I have always hated this version as either the flex cables fracture or the soldered interconnect "rivets" through the fixed pcbs fail to make contact.

My fault was no ac volts readings at all and a meter that swung widely, indicating no shunting across it. All other ranges are working, following a little careful switch contact cleaning.

I flipped up the main ac pcb from behind the display and inspected the rivets. As you can see from the photo, many are just pressed in, with no solder at all, although some are soldered. They are soldered on the other side of course, to the flexi-cable.

I re-worked the unsoldered ones nearest the transformer (right hand side under the black wire), using the absolute minimum of heat and extra liquid flux from a pen, but making sure that a small solder fillet now bridged between the rivet and the pcb trace. AC volts now work fine. Excess heat will quickly destroy the flexy pcb so take heed!

My question is whether these un-soldered rivets are an original feature, or a manufacturing flaw.

Whatever, they are a menace!

- Jeremy