"Arfa Daily" wrote in message
...
A Fender Supersonic combo landed on my bench as an urgent job today.
Ticket said "Power, but no output". The pilot light on the front panel lit
up, but that was about it. There was no sign of the output tubes being
alight at all. When I had removed the chassis from the cabinet, it was
clear that every filament in the whole amp was wired by a single parallel
run, and that this was common with the supply to the pilot light. There is
a 10 amp filament fuse in the line, that looks as though it might be after
the pilot light take off point, but the fuse was intact. You couldn't
immediately see the undersides of the first few preamp tubes on that
wiring run, due to there being a back panel PCB above them, which carried
the effects send and return jacks and a couple of pots etc. However, you
could get to the bottoms of the output tubes, and there was no voltage at
the filament pins of either.

I removed the PCB that was in the way, and it was then apparent what was
wrong. The hand soldering of just about all the tube socket wires, and
especially the thicker and doubled-up filament wires, was astoundingly
poor for a Fender branded product. The solder had not properly taken to
any of the filament pin tags on the tube bases, and the mechanical
appearance of each joint was appalling. The amp was definitely built
using lead-free solder, but it looked as though nobody had told the hand
assembly part of the production line, and they were trying to make the
joints with soldering irons with their tip temperature set to produce
correct joints with lower melting point leaded solder ...

A reflow of the offending joints with some new solder fed in, restored
the filament supply to the output tubes and those that followed after
them, and the amp then worked just fine.

Other than the normal references to Fender being in California USA, I
could find no indication of where this amp had actually been built. These
amps are not cheap, and I would normally associate the name Fender with a
quality product. In this case, however, I felt very disappointed for the
owner. In order for poor workmanship like this to find its way out of the
factory door, either the QA is non-existent or poorly structured, or else
the QA manager needs his arse firing out of the job ...

Arfa



"Wild_Bill" wrote in message
...
I've seen numerous examples in my own purchases (since I don't do regular
repair work anymore), where hand soldering has failed just from opening
the cases.

I always open any line voltage operated consumer/imported/China-made gear
to examine all of the hand assembly work.

What appears to be standard procedure is that the leads for attachment
have been tinned previously, so the assembler only needs to hold the iron
on the connection long enough to get the slightest amount of reflow to
take place, before moving on to the next connection.

The result in many cases is a temporary connection.. the way a welder
would tack-weld a part in place to hold it temporarily before doing the
finish weld which actually secures the part.

Good mechanical connections are essentially a thing of the past, rarely
ever performed in low-end equipment anymore.. at most (generally) a lead
might be poked thru a terminal hole before adding solder, but the leads of
the vacuum tube era were nearly always formed tightly around the terminal
before soldering.

Tacking pre-tinned leads to existing soldered connections is the present
standard of quality that's accepted, even by the marketers (rarely the
actual manufacturers) of better quality equipment.

I believe QA is a figment of the imagination any more, as far as consumer
gear goes.. I would expect that the highest priority is placed on the
external appearance of the finished product, and nothing else.

See.. store return policy.

A new consumer market acronym for the old use of MSRP..
Marketer's store return policy.

--
Cheers,
WB
.............



In general, I would agree, but for the most part, tubed guitar amps,
particularly from the 'big' names, are expensive specialist items, and
subject to limited production runs of hundreds at a time, rather than the
hundreds of thousands of cheap Chinese DVD players, or whatever. It is quite
normal for these amplifiers to have signed production progress stickers on
the chassis, and a final QA test sticker. Sometimes, even a 'musicality'
sticker, so I think that for the most part, QA in some form at least, still
exists for the majority of manufacturers of these products. Apart from this,
many examples have adjustable bias for the output tubes, so as a final or
almost final operation, a real person has to have their hands and eyes
inside the chassis to carry out this task.

As to the wires on this one, most were wrapped around the pins in at least a
token fashion, prior to being soldered. The filament wires were of a rather
thicker gauge which certainly *could* have been wrapped around the pins, but
wasn't, presumably because of the extra time that it would have taken to do
it neatly and properly. Or perhaps it was just an example of a lazy or
poorly trained production worker ? There was not really a *lack* of solder
on the joints, just that they were poor, with the solder having not stuck
'well' to either the wires or the tags on the bases. I would have to say
that it looked to me just typical of a joint - of any variety of solder -
that had been made with an iron that was either too cold, or not up to the
job in terms of tip thermal inertia. Or again, maybe just a worker that was
poorly trained in the art of soldering. Either way, poor workmanship like
this, really should have been picked up somewhere in the build process ...

Arfa