On Wed, 31 Aug 2011 10:59:58 +1000, "Phil Allison"
wrote:


** I had hoped that the dreaded Yellow Glue peril had gone away - but it is
still with us.

Most of you will have seen it holding parts down to PCBs on Asian made
equipment and many of those will have seen what happens if the parts
involved get hot.

The example on my bench is the SMPS from an Alesis powered monitor ( M1
Active, Chinese made) ) which has blown up big time because of the damn
Yellow Glue used to secure a ferrite toroidal coil. All the glue used had
gone brown or back ( ie carbonised ) on this coil and arced across nearby
tracks taking out the main switching MOSFET, its drive IC and associated
transistors, high speed diodes and even the AC bridge rectifier diodes.

The toroidal coil had to be un-wound, cleaned up and re-wound. The same glue
was attacking parts elsewhere on the board too ( it corrodes copper) and had
to be laboriously scraped off.

Are the dickheads who squirt this horrible goop all over PCBs NEVER going
to wake up ??



..... Phil




The rumor among techs in the U.S. when this stuff first showed up was
it was originally manufactured by Sony and it was known as "Sony
glue". Don't know if there was any truth to this or not. As Phil
said, it was in widespread use, for example: Mitsubishi televisions,
Adcom preamps and tuners, Yamaha receivers, Extron products and many
others which I can't recall off the top of my head. Chuck