Marshall AS100D, of 2008

[N_Cook]

No output unless in echo effects mode. Owner put away for 2 years. Covered
in PbF & Rohs stickers.
Now I find no problem . Send/Return/footsw sockets are not active bypass
configuration. Anti-feedback on/off switch is iffy but I doubt would kill
throughput .
Any known URL for a schematic out there?
Then how to reassemble the 4-off speaker wire routing, rod fed thru pcb hole
and chassis hole and load a speaker crimp connector on the end of the rod to
pull back through, crossing fingers that it will not dislodge? I'm not
skilled in chopstick use.

 

[Phil Allison]

"Nutcase Kook"


** The AS100D has "Made in India" on the back panel - right ?

While valve heads MA50H & MA100H have "Made in Vietnam" on the back..



..... Phil

 

[N_Cook]

Mail me off-group with a valid email address for receiving, Nigel

Arfa

will do

for the moment
The mute lines of the 2x LM3886 go to the ps, so only sw on/off muting.
Now the 3 sections of the amp are out of the chassis on the bench, to
explore the FX on/off line and the horrible white PbF solder "joints". The
designed-as skew-whiff digital FX board looks my sort of bodged
professionalism

A straight rod cannot pass through both pcb hole and chassis hole, so
probably chamfer off the edges of the crudely made pcb holes and then 4
pre-laid cords/wires to twist/temp fix through and to the sp wire crimps for
final re-assembly

 

[N_Cook]

As the FX board is only held on by 1 nylon screw on the other side from the
header , so eminently loosable, I tried running with the pcb removed , but
normal amp action , sans-FX with FX sw in either position

 

[N_Cook]

if the mixed 1 and 2 signal fails to get to the output amps then there is a
second route via the effects board, but that route is fixed , ie no header
connectors , switches or pot wipers, leaving dodgy pbf.
I cannot see how failing switches for the anti-feedback notch filters could
pulldown the ch1+ch2 mixer opamp.
Probably resolder all in that area

 

[N_Cook]

Textbook logical fault-finding , shame PbF is not logical. If I make a
leaded component / wire link mechanical tester, anyone know what force you
should be able to apply without the lead pulling through the solder. I use
thin nose pliers and some undefined , but attempted consistency, amount of
finger applied force at the moment.

Wire link failed this pull test on one end and now that end is pulled
through the PbF, the other end rotates in its "joint" .
So mixed ch1 +ch2 from IC201p1 to the FX switch and FX board , including a
wire link, is ok (for now) and this failing link from there on towards yhe
other end of the pcb and the 68K/68K split out to the routes to the 2
output amps. So with failed link, signal through the FX board only

 

[N_Cook]

for "leaded component " read components with wire leads, not components with
lead/tin solder

 

[N_Cook]

UK school kids that is.

I was looking for an apprentice some years ago and got loads of job
applications from a few colleges, through the local employment agency. You
know, out of the 30 or so applications, not one candidate could write any
better than I could in primary school.
To say I found that shocking is a gross understatement.



Gareth.

I'm getting too much repair work in these days, how to find someone to take
off some of the load?
As an interim I will only have the phone ringer active perhaps two hours a
day, any other idea? Myself / friends/ local shop referrer + his friends ,
cannot find anyone to help out

 

[N_Cook]

The problem is finding anyone competent enough not to ruin your
reputation/business. If all your repairs start coming back you will have a
whole load of extra stress and problems to the ones you have now.

My advice would be to stay a one man band and limit your repair intake.
e.g. refuse all Hi-fi, Pro-audio, or whatever section you least like to deal
with, or makes you the least money with the most effort.

I know what it like to have a 2 to 3 week backlog and more - dreading every
phone call because most of them are customers wanting to know why you
haven't repaired their gear yet.
Its a nightmare world of stress you just don't need.



Gareth.

Your probably right , and the blame culture/ excess litigation these days

In this game it would be nice for somenone to to take on those PbF failed
guitar input sockets and failed flimsey send/return bypass switches but even
those repairs it is possible for a numbskull to replace a header the wrong
way etc .

I intend not touching anything over 20 Kg at some point, I have the spring
balance , that cutoff going down in weight over time.
The telephone business of a timer to the phone ringer (so to the outside
world the phone is ringing) because most of my work comes via phone and this
should deter the friends of friends. Nothing against them as customers but
its just a way of cutting down the numbers.
Like the job application sifting business of rejecting all applications that
come in on anything other than white paper , just to reduce the numbers
to something manageable.

 

[William Sommerwerck]

A guy that comes into one of our food joints is an exam marker.

The missus got talking to him about the state of education, and
a couple of days later, he brought in a GCSE level maths paper
for 15 year olds. They apparently had 90 minutes to complete this
paper, and were allowed to use a calculator. I was able to finish it,
in my head, in about 20 minutes. I think that I would have been able
to do the same at age 10, back in the days when we were taught
properly 40 odd years ago. The maths papers that we took back
then at age 15, were way, way above the level of this Mickey
Mouse paper. The standard even appears to have taken a nose-dive
since my own kids were that age 10 years or so ago.

The US of A is a country that believes the most-important thing in life --
other than trying to force your religious beliefs on other people -- is to
be "successful" (ie, wealthy and powerful). Getting a real education --
which includes science and the liberal arts -- is of no importance, unless
it promotes "success".

Ours is a profoundly anti-education, anti-intellectual country. This is
amazing, when you consider that most of the Founding Fathers were
intelligent, well-educated or well-read people.

I've never had trouble with math. Pardon the brag, but when I took the SATs
way back in 1965, I got an 800+ on the math part. * You read that right --
eight-hundred-plus. I asked about this. "How can you get a score higher than
800?" I was told 800 was not "perfect" -- just very high. And you could get
a score higher than /that/. Hence, the plus.

* I probably would have gotten an 800 on the English, if it hadn't been for
the analogies, which were thrown out several years ago.

 

[William Sommerwerck]

I'm getting too much repair work in these days,

how to find someone to take off some of the load?

If you were local, perhaps I could help out by triaging the items -- making
a preliminary judgment as to what's wrong, disassembling them, etc.

If you do hire somebody, make sure they care about doing a proper repair,
that won't bounce back.

 

[N_Cook]

If you were local, perhaps I could help out by triaging the items -- making
a preliminary judgment as to what's wrong, disassembling them, etc.

If you do hire somebody, make sure they care about doing a proper repair,
that won't bounce back.

It wouldn't be hiring anyone , just someone I can relay the contact details
of, if they can convince me they're any good. That referring shopkeeper
tried someone ten years ago and he was hopeless. I know what sort of test
questions I would ask and a check on his mechanical ability as well, some
people thes edays barely know how to use a screwdriver.

 

[Geo]

I'm getting too much repair work in these days, how to find someone to take
off some of the load?
As an interim I will only have the phone ringer active perhaps two hours a
day, any other idea? Myself / friends/ local shop referrer + his friends ,
cannot find anyone to help out

There are a lot of UK TV repair guys complaining that they are getting
less work and looking for new ideas (e.g laptop repairs).

 

[N_Cook]

An interesting evaluation. I always had the U.S. down as a country with good
all round education, much as we used to have. Certainly, all of the young
Americans that I have met on my travels there, have seemed polite at least,
which seems to me to be fundamental to getting educated. What has happened
here, is that a combination of liberal education policies, coupled with
over-liberal parenting, has resulted in primary school classes being filled
with disruptive and uncontrollable kids, in informal class situations that
do little or nothing to modify those behaviours. Add to that the fact that
the last two generations of teachers come from this background themselves,
and you have the degenerating standards that we have been seeing for the
last 25 years or more.

Once the early primary education has slipped to the level that it now has,
secondary and further education stands no realistic chance. If the kids
can't even read and write properly, what chance do they stand in other
subjects where they need to read, understand, and creatively write ? We now
have almost no scientists coming through our universities, which is very sad
when you consider that the UK once led the world in scientific discovery and
endeavour. Most universities now offer no maths courses at all. Science and
maths and English of course all go hand in hand, and if the students are not
getting a good enough grounding in core subjects like maths and English,
then any science subject will be a non-starter.

I find it all terribly sad and depressing. The world should advance, not
decline, but I guess that is the nature of the rise and collapse of great
civilisations, as has been seen many times throughout history.

Just a few weeks ago, I was reading a newspaper columnist who is a bit of a
bleeding-heart liberal, and she was defending educational standards on
behalf of her own kids, and was saying that she got fed up of listening to
people (like me presumably) who harped on about and decried the passing of a
golden age that never actually existed. I wanted to scream at the silly cow
that she was wrong wrong wrong, and that she was not qualified to comment as
she is not old enough to have been part of it.

Arfa

Perhaps there is a side issue that prople don't want to get their hands
dirty these days.
I arranged a talk by someone from The Culham labs , subject cold fusion
research. They find competent physics post-grads two a penny. But cannot
find competent welders/fitters/mechanics and technicians .