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: 18 April 2024 at 1:09am
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com
Topic: Spot the deliberate mistake
Posted By: kedwardsleisure
Subject: Spot the deliberate mistake
Date Posted: 03 December 2014 at 12:21pm
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Mackie CFX16-2 mixer with no left output Not good enough  ------------- 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?  ------------- Earplugs Are For Wimps! |
Posted By: bitSmasher
Date Posted: 03 December 2014 at 8:47pm
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Did it sound all right? |
Posted By: kedwardsleisure
Date Posted: 03 December 2014 at 10:27pm
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potato? ------------- Kevin North Staffordshire |
Posted By: Peter Jan
Date Posted: 03 December 2014 at 10:33pm
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I see a bent pin... |
Posted By: MattStolton
Date Posted: 04 December 2014 at 9:52pm
Bada bum tish! For a wackie, I reckon the left channel did sound better than normal. 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" |
bitSmasher wrote:Posted By: burningbush
Date Posted: 05 December 2014 at 2:20pm
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Deliberate mistake? It's not on fire? ------------- music is the message |
Posted By: Jimmer
Date Posted: 05 December 2014 at 2:33pm
  ------------- 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.   ------------- Earplugs Are For Wimps! |
Posted By: MattStolton
Date Posted: 15 December 2014 at 3:18pm
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Tinfoil, fag packet liner, or chewing gum wrapper? or 20A, 15A and 10A "field fuses" respectively.... ------------- 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
------------- No, it is not a line array it is some well stacked boxes............... |
Posted By: brokenjoe
Date Posted: 15 December 2014 at 6:33pm
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i found someone using a drill bit once.. nearly killed myself touching it at the back of his rack ------------- error 404 |
Posted By: KidCreole
Date Posted: 15 December 2014 at 6:43pm
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Doing an impersonation of Eric Morecambe? ------------- Mykey Wattco |
Posted By: DMorison
Date Posted: 15 December 2014 at 8:53pm
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 |
Posted By: Kobe
Date Posted: 15 December 2014 at 9:59pm
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manufacturer fault on a brand new from the factory Gemini PL02 PDU (clue - the whole chassis was tingly to the touch!!) 
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Posted By: Pinyorouk
Date Posted: 15 December 2014 at 10:52pm
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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
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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.  ------------- Earplugs Are For Wimps! |
Posted By: kedwardsleisure
Date Posted: 05 February 2015 at 12:04am
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Maybe the person who did the PAT testing at the end of the production line had flu that day. ------------- 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. ------------- Kevin North Staffordshire |
Posted By: ceharden
Date Posted: 05 February 2015 at 12:30am
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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.
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Posted By: _djk_
Date Posted: 05 February 2015 at 2:34am
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One of the devices on the bottom sink looks like a fake. ------------- djk |
Posted By: odc04r
Date Posted: 05 February 2015 at 9:11am
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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
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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?  ------------- Kevin North Staffordshire |
Posted By: odc04r
Date Posted: 05 February 2015 at 2:36pm
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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
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"Yes FIVE different types of output transistor." So designed to work over 5 different frequency bands! ------------- Earplugs Are For Wimps! |
Posted By: Peter Jan
Date Posted: 05 February 2015 at 4:58pm
Nah... can't you see ? Someone made it into a 5-tier Class H design |
Posted By: kedwardsleisure
Date Posted: 12 March 2015 at 5:40pm
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Soft Start relay from Macrotech 5002VZ. Complaint of mains transformer humming even with power switch 'off'.  ------------- Kevin North Staffordshire |
Posted By: burningbush
Date Posted: 12 March 2015 at 5:53pm
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Vent hole conversion, runs cooler now. ------------- music is the message |
Posted By: mini-mad
Date Posted: 12 March 2015 at 10:35pm
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..bass port? Explains why they chug out bass all nite long... ------------- If it sounds like a gorilla is trying to escape, turn it down. |
Posted By: Earplug
Date Posted: 13 March 2015 at 8:35am
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Another bullet hole? ------------- Earplugs Are For Wimps! |
Posted By: kedwardsleisure
Date Posted: 13 March 2015 at 1:15pm
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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. ------------- Kevin North Staffordshire |
Posted By: MattStolton
Date Posted: 13 March 2015 at 3:28pm
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  ------------- Kevin North Staffordshire |
Posted By: all bass
Date Posted: 18 March 2015 at 5:52pm
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Trying to recreate the Belchfire i guess... ------------- https://www.instagram.com/my_modular_journey/ |
Posted By: djeddie
Date Posted: 18 March 2015 at 9:16pm
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I wonder who did the soldering, the blind guy or his guide dog? ------------- 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
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The plaster guy, he used a trowl. ------------- djk |
Posted By: odc04r
Date Posted: 19 March 2015 at 9:12am
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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
------------- If it sounds like a gorilla is trying to escape, turn it down. |
Posted By: djeddie
Date Posted: 19 March 2015 at 9:30pm
Suppose so... it did look quite ruff.  ------------- 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
------------- If it sounds like a gorilla is trying to escape, turn it down. |
Posted By: kedwardsleisure
Date Posted: 19 March 2015 at 11:02pm
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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. ------------- Kevin North Staffordshire |
Posted By: _djk_
Date Posted: 19 March 2015 at 11:13pm
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"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. ------------- djk |
Posted By: kedwardsleisure
Date Posted: 23 March 2015 at 3:01pm
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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 ------------- 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. ------------- Kevin North Staffordshire |
Posted By: MattStolton
Date Posted: 23 March 2015 at 3:12pm
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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
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Mackie SWA1501. Been to another dealer twice who couldn't find the fault. Symptoms: Volume goes up & down on its own  ------------- Kevin North Staffordshire |
Posted By: Earplug
Date Posted: 21 April 2015 at 1:29pm
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Self-regulating fuse? Very clever device, really. Someone should take out a patent. ------------- Earplugs Are For Wimps! |
Posted By: odc04r
Date Posted: 21 April 2015 at 2:32pm
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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
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I don't know, I never get told ------------- Kevin North Staffordshire |
Posted By: audiomik
Date Posted: 22 April 2015 at 4:48pm
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 ------------- 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 ------------- Kevin North Staffordshire |
Posted By: mini-mad
Date Posted: 23 April 2015 at 1:48pm
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Please please please tell me thats your screwdriver and you put it there... ------------- If it sounds like a gorilla is trying to escape, turn it down. |
Posted By: Earplug
Date Posted: 23 April 2015 at 2:33pm
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That´s quite novel - free screwdiver with every mixer. I hope it´s got a decent tip on it. ------------- Earplugs Are For Wimps! |
Posted By: kedwardsleisure
Date Posted: 23 April 2015 at 2:57pm
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No I found that in there ------------- Kevin North Staffordshire |
Posted By: GAZ.
Date Posted: 23 April 2015 at 3:38pm
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On board tools! That's a feature you don't come across often... ------------- 100% Earth Moving Bass |
Posted By: MattStolton
Date Posted: 23 April 2015 at 7:22pm
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 ------------- Kevin North Staffordshire |
Posted By: MattStolton
Date Posted: 27 April 2015 at 12:28pm
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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? ------------- 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
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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. ------------- Kevin North Staffordshire |
Posted By: MattStolton
Date Posted: 27 April 2015 at 5:14pm
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
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The customer is always right! ------------- Earplugs Are For Wimps! |
Posted By: michel29
Date Posted: 27 April 2015 at 7:24pm
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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
on 17-18 stereo channel ? |
Posted By: kedwardsleisure
Date Posted: 27 April 2015 at 7:37pm
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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!! ------------- Kevin North Staffordshire |
Posted By: michel29
Date Posted: 27 April 2015 at 9:19pm
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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. ------------- Kevin North Staffordshire |
Posted By: MattStolton
Date Posted: 31 March 2016 at 3:15pm
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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
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Yeah, looks like a DIP header got placed 0.1" off! |
Posted By: kedwardsleisure
Date Posted: 31 March 2016 at 8:44pm
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no, the holes are just for an alternative connector. Nothing wrong there! ------------- Kevin North Staffordshire |
Posted By: Jimmer
Date Posted: 31 March 2016 at 8:54pm
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Missing resistor above 33n cap?
Edit* Is that actually a resistor in R5? ------------- 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
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No, its more obvious than that. I should say that a.n.other had serviced this unit before I saw it. ------------- Kevin North Staffordshire |
Posted By: Jimmer
Date Posted: 31 March 2016 at 9:48pm
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Nylon screw on the earth?... failing that i'm stumped!! ------------- 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
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Class Y cap in not exactly a line filter application? |
Posted By: madboffin
Date Posted: 31 March 2016 at 10:31pm
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Looks like a nylon screw to me too... |
Posted By: MattStolton
Date Posted: 01 April 2016 at 9:42am
+1 on this. That track/screw head is even labelled "E". Missed that.  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.  ------------- Kevin North Staffordshire |
Posted By: Jimmer
Date Posted: 01 April 2016 at 5:32pm
------------- 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'  ------------- Kevin North Staffordshire |
Posted By: jbl_man
Date Posted: 26 April 2016 at 11:36am
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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. ------------- Be seeing you. |
Posted By: kedwardsleisure
Date Posted: 26 April 2016 at 1:01pm
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no, bridge rectifier splattered across the chassis ------------- Kevin North Staffordshire |
Posted By: Earplug
Date Posted: 26 April 2016 at 1:03pm
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Capacitors are fun: https://www.youtube.com/watch?v=9jDsNe_bmtE&index=52&list=PL5Qevr-CpW_yZZjYspehnFc-QRKQMCKHB&nohtml5=False ------------- Earplugs Are For Wimps! |
Posted By: kedwardsleisure
Date Posted: 26 April 2016 at 7:49pm
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eevblog, best watched with the sound muted. ------------- 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
Agreed. Allways seems to take him 10 minutes to explain something that should take 30 seconds. ------------- Be seeing you. |
Posted By: Earplug
Date Posted: 27 April 2016 at 10:19am
Australian humour takes longer to explain. I do like his teardowns (and letter opener ).------------- 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
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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
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The thermistor has been oddly mounted on its side but that's not the problem ------------- Kevin North Staffordshire |
Posted By: jbl_man
Date Posted: 29 April 2016 at 2:39pm
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Is that little relax box melted on the top corner? Looks like someone has poked it with a hot soldering iron. ------------- Be seeing you. |
Posted By: MattStolton
Date Posted: 29 April 2016 at 2:44pm
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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
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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
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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
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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
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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! ------------- Kevin North Staffordshire |
Posted By: MattStolton
Date Posted: 29 April 2016 at 3:27pm
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
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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
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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 |