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Spot the deliberate mistake

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Category: General
Forum Name: General Forum
Forum Description: Open Discussion / Questions
URL: https://forum.speakerplans.com/forum_posts.asp?TID=89735
Printed Date: 30 September 2022 at 2:26pm
Software Version: Web Wiz Forums 12.05 - http://www.webwizforums.com


Topic: Spot the deliberate mistake
Posted By: kedwardsleisure
Subject: Spot the deliberate mistake
Date Posted: 03 December 2014 at 12:21pm
Mackie CFX16-2 mixer with no left output

Not good enough



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Kevin

North Staffordshire




Replies:
Posted By: spongebob
Date Posted: 03 December 2014 at 12:41pm
Photo taken with a potato? Is that it?

Or did the thru-hole fader leg no quite make it thru the hole?


Posted By: Earplug
Date Posted: 03 December 2014 at 1:25pm
Hybrid surface-mount slider?   Smile




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Earplugs Are For Wimps!


Posted By: bitSmasher
Date Posted: 03 December 2014 at 8:47pm
Did it sound all right?


Posted By: kedwardsleisure
Date Posted: 03 December 2014 at 10:27pm
potato?

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Kevin

North Staffordshire



Posted By: Peter Jan
Date Posted: 03 December 2014 at 10:33pm
I see a bent pin...


Posted By: MattStolton
Date Posted: 04 December 2014 at 9:52pm
Originally posted by bitSmasher bitSmasher wrote:

Did it sound all right?

Bada bum tish!
 

For a wackie, I reckon the left channel did sound better than normal.

I'll get my coat.


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Matt Stolton - Technical Director (!!!) - http://www.wildingsound.co.uk" rel="nofollow - Wilding Sound Ltd
"Sparkius metiretur vestra" - "Meter Your Mains"


Posted By: burningbush
Date Posted: 05 December 2014 at 2:20pm
Deliberate mistake?
It's not on fire?


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music is the message


Posted By: Jimmer
Date Posted: 05 December 2014 at 2:33pm
Originally posted by bitSmasher bitSmasher wrote:

Did it sound all right?

LOL Clap


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Light travels faster than sound....That's why some people appear bright until you hear them speak!


Posted By: Earplug
Date Posted: 15 December 2014 at 3:15pm
Well, it´s been a while since I´ve seen one of these:





It´s going to be an interesting repair.  Confused  Ouch  Confused




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Earplugs Are For Wimps!


Posted By: MattStolton
Date Posted: 15 December 2014 at 3:18pm
Tinfoil, fag packet liner, or chewing gum wrapper? or 20A, 15A and 10A "field fuses" respectively....

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Matt Stolton - Technical Director (!!!) - http://www.wildingsound.co.uk" rel="nofollow - Wilding Sound Ltd
"Sparkius metiretur vestra" - "Meter Your Mains"


Posted By: Shaun
Date Posted: 15 December 2014 at 3:41pm
Originally posted by MattStolton MattStolton wrote:

Tinfoil, fag packet liner, or chewing gum wrapper? or 20A, 15A and 10A "field fuses" respectively....


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No, it is not a line array it is some well stacked boxes...............


Posted By: brokenjoe
Date Posted: 15 December 2014 at 6:33pm
i found someone using a drill bit once.. 

nearly killed myself touching it at the back of his rack 


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error 404


Posted By: KidCreole
Date Posted: 15 December 2014 at 6:43pm
Doing an impersonation of Eric Morecambe?


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Speakers don't pay bills...but they do now


Posted By: DMorison
Date Posted: 15 December 2014 at 8:53pm
Originally posted by Earplug Earplug wrote:

Well, it´s been a while since I´ve seen one of these:





It´s going to be an interesting repair.  Confused  Ouch  Confused



Fцck me, I’d heard stories about that happening but never believed they were anything but apocryphal! Surely whoever does that must be shortlisting themselves for Darwin Awards Confused



Posted By: Kobe
Date Posted: 15 December 2014 at 9:59pm
manufacturer fault on a brand new from the factory Gemini PL02 PDU (clue - the whole chassis was tingly to the touch!!)


Posted By: Pinyorouk
Date Posted: 15 December 2014 at 10:52pm
Neutral or live was connected to the Chassis? as blue wire that goes to the ground common is not going to the IEC ground pin?  Can also see a green and blue cable to the chassis earthing point if that is relevant.


Posted By: odc04r
Date Posted: 16 December 2014 at 10:05am
Hmm, going on that chassis bolt earth and neutral connected there?


Posted By: Earplug
Date Posted: 16 December 2014 at 1:42pm
That´s what´s called a fatal mistake. Horrible.   Dead




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Earplugs Are For Wimps!


Posted By: kedwardsleisure
Date Posted: 05 February 2015 at 12:04am
Maybe the person who did the PAT testing at the end of the production line had flu that day.

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Kevin

North Staffordshire



Posted By: kedwardsleisure
Date Posted: 05 February 2015 at 12:06am
This Dynacord Powermate 1000 came from another dealer, it had been repaired by AN Other and not lasted long.





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Kevin

North Staffordshire



Posted By: ceharden
Date Posted: 05 February 2015 at 12:30am
To a first glance, it looks horrible because they've mixed devices but on second thoughts they've probably replaced the whole of one side of the bridge so it's not s bad.  However, are they all genuine OnSemi.  Or am I missing something that I can't see clearly on this size image?

On third thought, I think I can just make out a mix of 15022's and 15024's on the bottom right quadrant.


Posted By: _djk_
Date Posted: 05 February 2015 at 2:34am
One of the devices on the bottom sink looks like a fake.

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djk


Posted By: odc04r
Date Posted: 05 February 2015 at 9:11am
Indeed, bit odd that the printing on that one is horizontal and the rest and vertical.


Posted By: kedwardsleisure
Date Posted: 05 February 2015 at 1:46pm
Yes FIVE different types of output transistor.
Using better ones on the repaired channel eg higher voltage versions of the regular transistor would be ok. We have MJ15022, MJ15023, MJ15024, MJ15025 and MJ15003.
Maybe on a cheap disco amp it would be the only answer but a PM1000..and it didn't work anyway?

   

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Kevin

North Staffordshire



Posted By: odc04r
Date Posted: 05 February 2015 at 2:36pm
Well maybe you get some spares out of it if they aren't all dead or counterfeit. Doubt the owner wants them back.


Posted By: Earplug
Date Posted: 05 February 2015 at 4:49pm
"Yes FIVE different types of output transistor."

So designed to work over 5 different frequency bands!  LOL




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Earplugs Are For Wimps!


Posted By: Peter Jan
Date Posted: 05 February 2015 at 4:58pm
Originally posted by Earplug Earplug wrote:

"Yes FIVE different types of output transistor."

So designed to work over 5 different frequency bands!  LOL


Nah... can't you see ? Someone made it into a 5-tier Class H design LOL


Posted By: kedwardsleisure
Date Posted: 12 March 2015 at 5:40pm
Soft Start relay from Macrotech 5002VZ.
Complaint of mains transformer humming even with power switch 'off'.





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Kevin

North Staffordshire



Posted By: burningbush
Date Posted: 12 March 2015 at 5:53pm
Vent hole conversion, runs cooler now.


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music is the message


Posted By: mini-mad
Date Posted: 12 March 2015 at 10:35pm
..bass port?

Explains why they chug out bass all nite long...



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If it sounds like a gorilla is trying to escape, turn it down.


Posted By: Earplug
Date Posted: 13 March 2015 at 8:35am
Another bullet hole?  Tongue




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Earplugs Are For Wimps!


Posted By: kedwardsleisure
Date Posted: 13 March 2015 at 1:15pm
it's been dinged by something but hard to see how, as it's pretty tight on the pcb and it hasn't been out before.

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Kevin

North Staffordshire



Posted By: MattStolton
Date Posted: 13 March 2015 at 3:28pm
Originally posted by kedwardsleisure kedwardsleisure wrote:

it's been dinged by something but hard to see how, as it's pretty tight on the pcb and it hasn't been out before.
Someone shoved a screw driver into it, to try and separate housing from internal gubbings.

Like how you remove engine oil filters on blocks, when stuck......


-------------
Matt Stolton - Technical Director (!!!) - http://www.wildingsound.co.uk" rel="nofollow - Wilding Sound Ltd
"Sparkius metiretur vestra" - "Meter Your Mains"


Posted By: kedwardsleisure
Date Posted: 18 March 2015 at 4:13pm
Another modified macrotech





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Kevin

North Staffordshire



Posted By: all bass
Date Posted: 18 March 2015 at 5:52pm
Trying to recreate the Belchfire i guess...

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Get your free line array plans here!


Posted By: djeddie
Date Posted: 18 March 2015 at 9:16pm
I wonder who did the soldering, the blind guy or his guide dog?


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Chas n Dave : it's like Drum and Bass but with beards.             E=mc² ±3dB


Posted By: _djk_
Date Posted: 18 March 2015 at 10:02pm
The plaster guy, he used a trowl.

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djk


Posted By: odc04r
Date Posted: 19 March 2015 at 9:12am
Can't tell if it has actually gone bang, or is just covered in crud and a very badly installed capacitor.


Posted By: mini-mad
Date Posted: 19 March 2015 at 11:26am
Originally posted by djeddie djeddie wrote:

I wonder who did the soldering, the blind guy or his guide dog?
his dog.... you can tell. It was 'paw' effort on his part lol


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If it sounds like a gorilla is trying to escape, turn it down.


Posted By: djeddie
Date Posted: 19 March 2015 at 9:30pm
Originally posted by mini-mad mini-mad wrote:

Originally posted by djeddie djeddie wrote:

I wonder who did the soldering, the blind guy or his guide dog?
his dog.... you can tell. It was 'paw' effort on his part lol


Suppose so... it did look quite ruff. Wink


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Chas n Dave : it's like Drum and Bass but with beards.             E=mc² ±3dB


Posted By: mini-mad
Date Posted: 19 March 2015 at 10:55pm
Originally posted by djeddie djeddie wrote:

Originally posted by mini-mad mini-mad wrote:

Originally posted by djeddie djeddie wrote:

I wonder who did the soldering, the blind guy or his guide dog?
his dog.... you can tell. It was 'paw' effort on his part lol


Suppose so... it did look quite ruff. Wink
a bit of DOG-dgy soldering and 'WOOF' gone in a flash!


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If it sounds like a gorilla is trying to escape, turn it down.


Posted By: kedwardsleisure
Date Posted: 19 March 2015 at 11:02pm
I'm more annoyed that the wrong capacitor was bodged in on stilts when the correct capacitors are available.

The other bodge is that there are 3 different output transistors in a row. Another half-arsed repair that has to be dealt before the current fault is traced.

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Kevin

North Staffordshire



Posted By: _djk_
Date Posted: 19 March 2015 at 11:13pm
"The other bodge is that there are 3 different output transistors in a row"
 
Might be OK as they are all PNP, they are usually like peas in a pod. NPN's however vary all over the map as far as gain goes.
 
I buy in trays of 100pcs and write the gain on each with a sharpie, it's a waste of time with the PNP's. It's very needed with the NPN's.


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djk


Posted By: kedwardsleisure
Date Posted: 23 March 2015 at 3:01pm
Crown also match by Vbe as well as gain. In the UK that would be just under 2 grand for a tray of 100 transistors or $2700

Nice work it you can get it



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Kevin

North Staffordshire



Posted By: kedwardsleisure
Date Posted: 23 March 2015 at 3:03pm
Geni OBY3 moving head with various faults this being one of them.



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Kevin

North Staffordshire



Posted By: MattStolton
Date Posted: 23 March 2015 at 3:12pm
That chip is pissed, at least a bit legless....

-------------
Matt Stolton - Technical Director (!!!) - http://www.wildingsound.co.uk" rel="nofollow - Wilding Sound Ltd
"Sparkius metiretur vestra" - "Meter Your Mains"


Posted By: kedwardsleisure
Date Posted: 21 April 2015 at 1:11pm
Mackie SWA1501.
Been to another dealer twice who couldn't find the fault.
Symptoms: Volume goes up & down on its own





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Kevin

North Staffordshire



Posted By: Earplug
Date Posted: 21 April 2015 at 1:29pm
Self-regulating fuse? Very clever device, really. Someone should take out a patent.






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Earplugs Are For Wimps!


Posted By: odc04r
Date Posted: 21 April 2015 at 2:32pm
Was one of the other dealers the same chap who modified the macrotech from 2 pages back?


Posted By: kedwardsleisure
Date Posted: 22 April 2015 at 12:01pm
I don't know, I never get told


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Kevin

North Staffordshire



Posted By: audiomik
Date Posted: 22 April 2015 at 4:48pm
Originally posted by Earplug Earplug wrote:

Self-regulating fuse? Very clever device, really. Someone should take out a patent.


Actually built something like a 'self regulating fuse' a while back - a variation on a Constant Current source - was for limiting the DC Current to a motor......!

Mik

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Warning! May contain Nuts
plus springs, washers, screws, etc, etc.


Posted By: kedwardsleisure
Date Posted: 23 April 2015 at 12:45pm
Phonic powered mixer, apparently went bang






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Kevin

North Staffordshire



Posted By: mini-mad
Date Posted: 23 April 2015 at 1:48pm
Please please please tell me thats your screwdriver and you put it there...



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If it sounds like a gorilla is trying to escape, turn it down.


Posted By: Earplug
Date Posted: 23 April 2015 at 2:33pm
That´s quite novel - free screwdiver with every mixer. I hope it´s got a decent tip on it.   LOL




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Earplugs Are For Wimps!


Posted By: kedwardsleisure
Date Posted: 23 April 2015 at 2:57pm
No I found that in there

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Kevin

North Staffordshire



Posted By: GAZ.
Date Posted: 23 April 2015 at 3:38pm
On board tools! That's a feature you don't come across often...

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100% Earth Moving Bass


Posted By: MattStolton
Date Posted: 23 April 2015 at 7:22pm
Originally posted by kedwardsleisure kedwardsleisure wrote:

No I found that in there
You have to be kidding, right?

I panicked when I first saw the photo, couldn't see the fault, and thought you were using the insulated screwdriver to hold the board up from (metal) chassis, for testing access.

Thought I was an idiot, for not being able to spot the dodgey component, and annoyed at the low res nes of the photo, which was clearly what was stopping me from spotting the problem!!


-------------
Matt Stolton - Technical Director (!!!) - http://www.wildingsound.co.uk" rel="nofollow - Wilding Sound Ltd
"Sparkius metiretur vestra" - "Meter Your Mains"


Posted By: ceharden
Date Posted: 23 April 2015 at 8:17pm
Which Phonic unit is it?  Took me a couple of attempts to fix the PSU in one a few years ago that had blown itself to pieces.  Most annoying thing was finding out it was pretty crap even fully working and I shouldn't really have bothered!


Posted By: kedwardsleisure
Date Posted: 27 April 2015 at 12:14pm
Digidesign Focusrite Control 24 Digital Desk / Surface








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Kevin

North Staffordshire



Posted By: MattStolton
Date Posted: 27 April 2015 at 12:28pm
Mis-aligned loom connector, the red wire does not connect to a pin? And one PCB pin does not connect to a black wire, and all others are connected 1 left of where they should?

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Matt Stolton - Technical Director (!!!) - http://www.wildingsound.co.uk" rel="nofollow - Wilding Sound Ltd
"Sparkius metiretur vestra" - "Meter Your Mains"


Posted By: kedwardsleisure
Date Posted: 27 April 2015 at 4:50pm
too easy!
I wish the client had told me he'd been fiddling rather than just say the fault had got steadily worse over the last couple of years.

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Kevin

North Staffordshire



Posted By: MattStolton
Date Posted: 27 April 2015 at 5:14pm
Originally posted by kedwardsleisure kedwardsleisure wrote:

too easy!
I wish the client had told me he'd been fiddling rather than just say the fault had got steadily worse over the last couple of years.
We have been known to be told one thing by customer, only to find out completely to the contrary. Very frustrating. It is like we are fault finding the equipment, and the customer? Makes no sense, as it would cost the customer more, as you have to find the original fault, and anything they have done.....


-------------
Matt Stolton - Technical Director (!!!) - http://www.wildingsound.co.uk" rel="nofollow - Wilding Sound Ltd
"Sparkius metiretur vestra" - "Meter Your Mains"


Posted By: Earplug
Date Posted: 27 April 2015 at 6:15pm

The customer is always right!




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Earplugs Are For Wimps!


Posted By: michel29
Date Posted: 27 April 2015 at 7:24pm
same mistake found on my Mackie CFX20 MK2
on 17-18 stereo channel , no action for the fader on right channel

deliberate mistake on CFX mixers ?


Posted By: michel29
Date Posted: 27 April 2015 at 7:25pm
Originally posted by kedwardsleisure kedwardsleisure wrote:

Mackie CFX16-2 mixer with no left output

Not good enough



on 17-18  stereo channel ?


Posted By: kedwardsleisure
Date Posted: 27 April 2015 at 7:37pm
They'll be fitted by an auto-insertion machine, so I suppose if something is out of tolerance, or worn on the machine or component, it won't take many minutes before a whole batch of them could be suspect. ATE will pass them if the pin touches when everything's nice and fresh.
Some of these machines are run into the ground, and some are very well maintained...I used to fix boards for a company who serviced pick n place machines and he could tell tales!!


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Kevin

North Staffordshire



Posted By: michel29
Date Posted: 27 April 2015 at 9:19pm
no or bad verification after assembling ?


Posted By: kedwardsleisure
Date Posted: 31 March 2016 at 3:03pm
Part of an amplifier--sort of; servo amplifier out of a CNC machine.



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Kevin

North Staffordshire



Posted By: MattStolton
Date Posted: 31 March 2016 at 3:15pm
12 missing pins between board and green connector?

-------------
Matt Stolton - Technical Director (!!!) - http://www.wildingsound.co.uk" rel="nofollow - Wilding Sound Ltd
"Sparkius metiretur vestra" - "Meter Your Mains"


Posted By: odc04r
Date Posted: 31 March 2016 at 4:49pm
Yeah, looks like a DIP header got placed 0.1" off!


Posted By: kedwardsleisure
Date Posted: 31 March 2016 at 8:44pm
no, the holes are just for an alternative connector. Nothing wrong there!

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Kevin

North Staffordshire



Posted By: Jimmer
Date Posted: 31 March 2016 at 8:54pm
Missing resistor above 33n cap?

Edit* Is that actually a resistor in R5?


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Light travels faster than sound....That's why some people appear bright until you hear them speak!


Posted By: kedwardsleisure
Date Posted: 31 March 2016 at 9:41pm
No, its more obvious than that. I should say that a.n.other had serviced this unit before I saw it.

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Kevin

North Staffordshire



Posted By: Jimmer
Date Posted: 31 March 2016 at 9:48pm
Nylon screw on the earth?... failing that i'm stumped!! LOL

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Light travels faster than sound....That's why some people appear bright until you hear them speak!


Posted By: odc04r
Date Posted: 31 March 2016 at 10:28pm
Class Y cap in not exactly a line filter application?


Posted By: madboffin
Date Posted: 31 March 2016 at 10:31pm
Looks like a nylon screw to me too...


Posted By: MattStolton
Date Posted: 01 April 2016 at 9:42am
Originally posted by Jimmer Jimmer wrote:

Nylon screw on the earth?... failing that i'm stumped!! LOL
+1 on this. That track/screw head is even labelled "E".

Missed that. Embarrassed

I thought the header to PCB was too easy....


-------------
Matt Stolton - Technical Director (!!!) - http://www.wildingsound.co.uk" rel="nofollow - Wilding Sound Ltd
"Sparkius metiretur vestra" - "Meter Your Mains"


Posted By: kedwardsleisure
Date Posted: 01 April 2016 at 11:18am
Jimmer wins an out of date easter egg. One of the nylon screws that should hold the power board to the chassis has been swapped with the earth screw for the case, and vice versa.

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Kevin

North Staffordshire



Posted By: Jimmer
Date Posted: 01 April 2016 at 5:32pm
Originally posted by kedwardsleisure kedwardsleisure wrote:

Jimmer wins an out of date easter egg.




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Light travels faster than sound....That's why some people appear bright until you hear them speak!


Posted By: kedwardsleisure
Date Posted: 26 April 2016 at 9:57am
'Capacitors guaranteed to vent safely'



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Kevin

North Staffordshire



Posted By: jbl_man
Date Posted: 26 April 2016 at 11:36am
Looks like a hamster nest!

Was it still working Kev? I bought a ppx450 that was working,but down on power,and clip lights on,same fault as above,but not quite as dramatic.


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Be seeing you.


Posted By: kedwardsleisure
Date Posted: 26 April 2016 at 1:01pm
no, bridge rectifier splattered across the chassis

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Kevin

North Staffordshire



Posted By: Earplug
Date Posted: 26 April 2016 at 1:03pm
Capacitors are fun:


https://www.youtube.com/watch?v=9jDsNe_bmtE&index=52&list=PL5Qevr-CpW_yZZjYspehnFc-QRKQMCKHB&nohtml5=False


LOL




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Earplugs Are For Wimps!


Posted By: kedwardsleisure
Date Posted: 26 April 2016 at 7:49pm
eevblog, best watched with the sound muted.

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Kevin

North Staffordshire



Posted By: ceharden
Date Posted: 26 April 2016 at 8:29pm
That must have gone with a 'loud report' as they say in the pyro biz


Posted By: jbl_man
Date Posted: 26 April 2016 at 8:49pm
Originally posted by kedwardsleisure kedwardsleisure wrote:

eevblog, best watched with the sound muted.


Agreed. Allways seems to take him 10 minutes to explain something that should take 30 seconds.


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Be seeing you.


Posted By: Earplug
Date Posted: 27 April 2016 at 10:19am
Originally posted by jbl_man jbl_man wrote:

Originally posted by kedwardsleisure kedwardsleisure wrote:

eevblog, best watched with the sound muted.


Agreed. Allways seems to take him 10 minutes to explain something that should take 30 seconds.



Australian humour takes longer to explain. I do like his teardowns (and letter opener  Smile).






-------------
Earplugs Are For Wimps!


Posted By: kedwardsleisure
Date Posted: 29 April 2016 at 10:15am
Crown MA5002VZ. Spot the deliberate mistake. The fault is present on both channels.






-------------
Kevin

North Staffordshire



Posted By: odc04r
Date Posted: 29 April 2016 at 11:10am
That's a rather off mounting of the radial thermistor, did it arc to the IC and transformer behind it? They appear damaged.


Posted By: kedwardsleisure
Date Posted: 29 April 2016 at 2:34pm
The thermistor has been oddly mounted on its side but that's not the problem

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Kevin

North Staffordshire



Posted By: jbl_man
Date Posted: 29 April 2016 at 2:39pm
Is that little relax box melted on the top corner? Looks like someone has poked it with a hot soldering iron.


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Be seeing you.


Posted By: MattStolton
Date Posted: 29 April 2016 at 2:44pm
That big fuse is in back to front, and isn't gold plated. Anyone who sells hi-fi knows fuses are directional (in AC supply), and if not made of gold, and polished on the thigh of a vestral virgin, it won't work.

I'll get my coat.


-------------
Matt Stolton - Technical Director (!!!) - http://www.wildingsound.co.uk" rel="nofollow - Wilding Sound Ltd
"Sparkius metiretur vestra" - "Meter Your Mains"


Posted By: MattStolton
Date Posted: 29 April 2016 at 2:48pm
The spade terminal poking up from the board (the one with two blue insulated spade wire terminals below, and six blue insulated spade wires terminals above), should have a wire attached to it? Or is it a 220/240/110V option connection point?

-------------
Matt Stolton - Technical Director (!!!) - http://www.wildingsound.co.uk" rel="nofollow - Wilding Sound Ltd
"Sparkius metiretur vestra" - "Meter Your Mains"


Posted By: MattStolton
Date Posted: 29 April 2016 at 2:58pm
Ignore me, P742 has no connection at 200/208/220/240V.

However, I guess one of the others is on the wrong terminal for the voltage?


-------------
Matt Stolton - Technical Director (!!!) - http://www.wildingsound.co.uk" rel="nofollow - Wilding Sound Ltd
"Sparkius metiretur vestra" - "Meter Your Mains"


Posted By: MattStolton
Date Posted: 29 April 2016 at 3:03pm
Got it!

K700/K701 should be 30A 24V Relays, the one fitted is 1A!!!

Cheeky, what with the legend on the relay being up side down.


-------------
Matt Stolton - Technical Director (!!!) - http://www.wildingsound.co.uk" rel="nofollow - Wilding Sound Ltd
"Sparkius metiretur vestra" - "Meter Your Mains"


Posted By: kedwardsleisure
Date Posted: 29 April 2016 at 3:16pm
I think the relay was melted a bit by the soldering iron trying to change the thermistor without lifting the board to gain access.
But that's not the fault either! It's more subtle.

Keep Guessing!

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Kevin

North Staffordshire



Posted By: MattStolton
Date Posted: 29 April 2016 at 3:27pm
Originally posted by kedwardsleisure kedwardsleisure wrote:

....Keep Guessing!

Damn it, I thought I had it. "Sacafrasenraisinfrasen" as Muttley once said....


-------------
Matt Stolton - Technical Director (!!!) - http://www.wildingsound.co.uk" rel="nofollow - Wilding Sound Ltd
"Sparkius metiretur vestra" - "Meter Your Mains"


Posted By: MattStolton
Date Posted: 29 April 2016 at 3:44pm
Ok, another guess, or two....

IC U708 "LM393 Dual Comparator" chip, immediately to the right of the grey electrolytic cap C719, appears to have a tantalum cap sitting on top of it, can't see why it should be there?

D721 and D722 are missing, but says they should be missing.

I can't see the orientation notch on the white ICs, U710/U706 Optos, are they mis-aligned 180 degrees?


-------------
Matt Stolton - Technical Director (!!!) - http://www.wildingsound.co.uk" rel="nofollow - Wilding Sound Ltd
"Sparkius metiretur vestra" - "Meter Your Mains"


Posted By: odc04r
Date Posted: 29 April 2016 at 4:04pm
You'd assume the Ta or ceramic cap was someones attempt to add some decoupling to the IC. Apart from that I dunno.

If someone has already had a go at it then it probably isn't the ICs as they look factory soldered, unless someone fed the pick and place tool backwards



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