Elvis Kabong wrote in message
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"N Cook" wrote in message
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Lord Valve wrote in message
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N Cook wrote:

Cut out in use then came back.
Next time failed to give output but owner noticed clip light in
pre-amp
functioned as normal
Now I have it, I cannot induce it to fail.

Of course not. ;-)

Anyone know of generic/specific Eden problems?
Likely suspects the discrete wire IDC connectors for power and
signal
interconnects, unsupported wire-wounds on end, mains thermal switch.
Anyone know the identity of the valve/tube ?

12AX7.

If it's got an effects loop (or pre-in pwr-out jacks)
check for dirty normalling contacts.

Lord Valve
Expert


Thanks for the info.
Do they remove the valve labelling ? no trace of anything on this one.
Send/return switches are the first things I look at with this sort of
problem along with speaker plug/lead
.
I wondered if there was any Eden specific problem areas. I've not
checked it
out but is that a thermal cutout in the mains feed , rather than
filter, to
monitor general chassis temperature, not the output N/O(cold) one for
the
fan

Their power supply boards have been known to become intermittent even
though
they are double-sided PCBs. You may really have to pound on the filter
caps to get the
bad one or the bad connection to act up. Also look underneath the supply
PCB for high
watt
ceramic resistors sitting on the chassis with heat sink compound on the
chassis
while they are soldered to the board but a lead may be broken and only
touching
where it's supposed to be soldered.

Sometimes the zeners and their current dropping resistors (more ceramic
ones)
for the plus/minus low voltage supply become overheated and melt solder or
get
bounced out of whack resulting in a loose lead.

I would suggest to run a signal thru it directly into the scope bypassing
the dummy load
while tapping and wiggling things around or get it heated up with a load
and tap around.
Try it both ways, but do it the cool way first, right?
Checked the pots for loose cases?
Customer already ruled out his bass, instrument cable, speaker cable and
cab or
did you?
Retighten the tube socket terminals and clean them?
Detachable AC cord plugged in firmly by the customer? Have him/her
demonstrate without
saying anything first. Then again, you just may have to have the customer
come in with
their entire rig and demonstrate the problem.
Whatever it is, good luck. I know the feeling.

Ed
Sonic Surgery
New Orleans
Earth



I did not like the front panel switch in line with the speaker line.
In standby instead of cutting/shorting the main amp input you switch out the
speaker. IDC interconnects on the speaker lines and power lines seem a bit
irregular to me but as cut out rather than distortion those power lines
presumably ok.
As 2 main bass speakers plus 1 in the cab, as sound died unlikely a problem
with a speaker but will check the wiring in there as well as the other
likely suspects.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
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