Should inexperienced members be encouraged to work on mains powered equipment?

[Hartley118]

I agree that there can be a culture and language gap between experienced technicians and total beginners, which is difficult to bridge on a forum.

For example, there's a tendency to assume that posters know how to solder properly, or the best way to remove and replace a component. This stuff is difficult to do over a forum.

Once upon a time in a galaxy far far away I used to teach practical electronics to a lab of 40 students, and the first task was to teach them to solder - simple enough if you're on the spot, but tricky in a forum.

The next task was understanding the resistor colour code - made even trickier today by more complex multiple colour banding. Getting it wrong can totally confuse the issue.

I'm all in favour of helping unskilled posters to fix real faults, but once their radio or record player is working, then encouraging them to get too deep into, for example, recapping, can be fraught with risk. Dire warnings of transformer failure risk mislead if it turns out to be a lesser evil than the damage wrought by uninformed messing about.

If it ain't broke, don't fix it, particularly if the poster's limited soldering ability is likely to introduce brand new 'dry joint' faults.

Martin

[Radio Wrangler]

As a kid I did mains wiring, fixed live-chassis sets and TVs and built myself a series of oscilloscopes with mains transformer propelled EHT. I got the odd belt, but never from that EHT.

Somehow I survived.

I did a degree and part of it involved practical work in power electrics in a lab with 415v 3 phase machines wired up with cables to exposed brass terminals.

I still survived

I got a job working in a modern electronics lab and everything outside +/-50v was shrouded carefully, and worked in this environment for over 30 years.

I got soft. I wasn't as wary of things because everything around me was so benign. Fortunately I understood this and I'm now very wary of anything with higher voltages in it. Wary, but not scared into avoidance. While developing a fancy high power SMPS, I had thermocouples all over it. Each one at a different potential and I changed which one was plugged into a handheld multimeter with the whole lot operating and live. Care, self-discipline and planning made it safe.

From personal experience I know that the care I take depends on the environment I've acclimatised to.

As far as health and safety are concerned, the risks and the consequences haven't changed one bit, but the background environment of most people has. Also what has changed has been the issue of holding people responsible and shunting blame around. There seem to no longer be "just an accidents" Where there's blame, there's a claim and there is now blame everywhere.

Colleagues used to tease accountants witht he 'bean counter' epithet. I came up with "Blame adjuster" for lawyers. Something regrettable happens and then all parties send their blame adjusters in to try to shunt the blame away from them. The umpire bangs his gavel and whoever loses pays up.

It's so much easier if no-one gets hurt in the first place.

David

[G6Tanuki]

The pragmatist in me says "They've shown they have the nous to have found this forum - the least we can do is guide them in the right direction".

If we simply refuse to talk to them they'll in all probability still go off and fiddle-around with things - in unstructured ways - for themselves.

In these days of RCDs and RCBOs, handling 240V mains is vastly less-likely-to-result-in-death than it would have in the immediately post-WWII era when many of us learned-on-the-job.

Still, I really see a place for the "proceed at your own risk" cover-your-behind legal disclaimers when we provide advice to newbies who've not yet found themselves on the bitey-end of domestic mains. "DEADLY SCORPIONS INSIDE! DO NOT OPEN THIS BOX!" will always be an unavoidable temptation for some.

[TonyDuell]

PJL makes a good point about deaths from drug abuse (something that I have never been tempted to try, I might add). I am pleased my parents encouraged me to use tools (sharp edges...), the mains, etc. It has provided a lifetime of enjoyment. Otherwise I might have turned to what Tom Lehrer called 'powdered happiness'...

And yes, knowledge and experience do not necessarily ensure you are safe. My paternal grandfather (who was an electrical engineer in the LMS power station at Wembley, and who alas died before I was born) apparently witnessed an experienced worker walk into a live switchgear cublicle. He did not come out alive....

I wonder.... In my case I was interested in electronics (and machinery, and...). I wanted to learn about it. I knew I would have to learn how to work safely. That was part of the hobby. Ditto learning to solder, learning use a lathe etc... My aim was not just to repair an old radio/Dansette/... I suspect the 'overheads' are rather more if you just have one repair you want to do.

[ms660]

Talking of risk and mentors, my first job as a drillers mate down the tin mines was with an old Polish bloke (the mentor driller and blaster) up in a shrinkage stope, all holes drilled off ok, time for the dynamite, back then we used to have to pay for the dynamite and there was also a penalty if you returned any that wasn't used, so off I trots to the magazine at the shaft station, shift boss says how many sticks, I told him but I'd got the number wrong, turns out that when charging the holes I'd brought back too much so had some sticks left over, what's to do with these I said, he said bury them further back in the stope, out of detonation range, I did that, then we blasted, next day we drilled off another round again, time for more dynamite, ok he said go dig those left over sticks from yesterday up...ok boss...me very carefully removing various rocks in turn to try and find them...found them yet...not yet boss...he then turns up with a pick and sinks the pick into a pile of rocks, pulls pick out with a stick of dynamite stuck on the end...there yer go...get digging.

Gulp.

Lawrence.

[David G4EBT]

Ironically, I'd say that the majority of equipment repaired and restored on this forum by very inexperienced newcomers is valved, often live chassis AC/DC or using an auto transformer, so is inherently as dangerous as it's possible to be. In the particular case which prompted this thread, only the connections to the motor and the two pole main switch are at mains voltage and the risks were well spelt out. If the terminals are covered up with insulating tape so they're not inadvertently touched, the rest of the equipment poses no more danger than working on say a transistorised battery portable radio, and far less than on DAC90s and the like.

How hard is that to understand?

Pity the next 'newbie' that comes onto the forum with his DAC90A or whatever, seeking help and encouragement.

He can be guaranteed no shortage of attention, that's for sure.

Ho hum.

[RojDW48]

Originally Posted by AC/HL

One point that occurs to me is that experienced people begin the fault diagnosis part way in. The basics are taken in with a quick look. It's easy to forget that a beginner can struggle to get to the point that our advice naturally starts, or looking the other way round it can be frustrating to us that a beginner can't follow what we think of as basics, but which aren't to them. Teaching is a skill quite apart from the subject taught.
Also, it can seem odd to us that someone just wants to repair one item, rather than make a lifetime's hobby, although that may follow.

Indeed - some of the advice must have looked like martian to a complete beginner. Hopefully he will do a bit of homework and come back for more. We all started out knowing nothing at all at some point.

[DaveVoorhis]

I've been working on electronics gear as a serious hobbyist for about 45 years. I started when I was six, fixing valve radios. I quickly moved to old TVs and fixed a lot of them, and got pretty good at it too. Some I took apart, and used modified high-voltage sections from colour sets to generate decoratively impressive multi-inch sparks, for a short time before the flyback transformer melted.

I never had anyone supervise me. I've received numerous shocks, burns, cuts, bruises. I've been splashed with chemicals and have inhaled smokes and vapours of every sort -- some involuntarily -- and have spent the last forty years riding motorcycles, off-road vehicles, unsafe cars, trucks, busses and every conceivable floating, tracked, wheeled and noisy-engined oily spinning fiery contraption. In my youth I manufactured explosives, mechanically unsafe gadgets of every kind, went to bars in the bad end of town and hung out with dangerous people.

I'm still here, and I bet I'm no different from 99% of the population. What kept me alive is reading sound advice, in books and whatnot, to wear appropriate safety gear, keep my bare hands off the terminals, watch out for live chassis, etc., etc., etc., and use common sense.

Last year, at about this time, a good friend of similar age and background -- whose youth was every bit as dangerous, mis-spent, and yet ordinary as mine -- slipped on the stairs in his home, crashed head-first into a brick wall and died instantly.

When your time's up, your time's up, and nothing will save you. In the mean time, the best thing you can do is offer reasonable advice, and nothing more, to beginners on forums like this one. Trying to cocoon some poor kid who just wants to fix his radio will do no good, and will only perpetuate the current unsightly trend of everyone being responsible for everyone else, but never for themselves.

If a noob can't take reasonable advice to avoid a fatal wattage frizzling his innards, then it's pretty obvious that (a) his time is up, and (b) let's hope he dies before he taints offspring with his faulty "common sense" gene.

I'm curious: How many of you have heard of someone losing their life because they electrocuted themselves attempting to fix a TV, radio, or stereo?

[stuboy57]

Originally Posted by ms660

No point in keeping the Decca Capri service sheet tab on my computer screen open anymore

Please don't give up on me I'm not a quitter and really want to get this Decca capri working......could i buy or get a mains isolation transformer and signal tracer?......might be good investment for future projects.
I can understand where you are all coming from and working with high voltages and mains electricity can be lethal.....but with a little mentoring and guidance I can do it and learn from the project hopefully without or lethal shocks.....I'm taking all advice on board.....really enjoying the discussions.......trouble is we all have to start somewhere......proceed with the utmost caution and check and double check before proceeding........thanks to you all

[Skywave]

Learning about radios and electronics: I can only report what worked for me. Started with time spent twiddling around the short-waves on the large Philips radio (a TG170A if I recall correctly.) Before I even contemplated looking inside it - let alone thinking in terms of fixing it, if necessary, or fixing any other similar item - I read as many text books on the subject of 'Radio' as I could. And learnt a lot in so doing. That included all the aspects of the hidden dangers where high voltages were concerned, a.c. mains and H.V. d.c. And a good deal of basic theory.

So my advice to any newcomer to our hobby is this: read as many text books on the subject first.* Supplement that by taking the back off and having a look inside - without the a.c. mains connected. And if it contains valves, there are (old) books aplenty and cheap, available via the 'usual sources'. Old valve radios; old radio books on old valve radios: information source matches the appropriate technology. √

* That sentence is not to imply that said newcomer should not visit this forum: doing both seems to be a good idea.

Al.

[ms660]

Originally Posted by stuboy57

Please don't give up on me I'm not a quitter and really want to get this Decca capri working.

Good man, I'm not a quitter either, Decca Capri trader sheet re-instated

Lawrence.

[kalee20]

I'd encourage newbies to work on mains powered equipment, with due cautions!

UK mains at 240V is not what I'd consider deadly, at least not in a home workshop with hopefully other people around. (Outside on wet ground, different matter). I have suffered several mains shocks, I'm not particularly proud of that, but it hasn't killed me.

However, UK mains IS sufficiently high enough voltage to be extremely unpleasant! You get a belt - hopefully not directly across your chest, or right down your body, you jump, you pause, have a breather, make a cup of tea, and appraise what went wrong. And it gives you an idea what higher voltages COULD do.

The Decca record player has nothing higher than mains voltage. Whereas, a conventional radio or amplifier with mains isolating transformer, does have two points (anodes of the rectifier valve) with 500V of AC or more between them.

So, it's not a bad project for a first-timer at all! It might bite - hard - but only with fairly major carelessness. And with the relevant points highlighted by David G4EBT above, there's every reason to think a safe investigation and a positive, successful, rewarding outcome is only a few hours of work away!

[Audio1950]

Well! I opened a right can of worms there. Let me explain the thinking behind my initial post. As stated, I never touch amplifiers, because they are a complete mystery to me. I can, however identify transformers, valves, resistors etc. and I can solder. If, one day I get hold of a record player I desperately want to restore, I would have no hesitation in coming on to the forum and asking for advice, knowing that it would be given generously. Until this thread started, I have never before advocated leaving anything alone, and will probably never be sufficiently alarmed to do so again, but as soon as I read the OPs question "What is an amplifier", then the alarm bells started ringing. It seemed somewhat dangerous to be giving technical advice to someone who clearly had never seen the inside of a record player. I must admit that at the time I did not appreciate that the Decca was transistorised, and therefore somewhat less of a hazard, but there are still mains voltages present, and the risk to a totally inexperienced person is surely greater than it would be to someone who at least recognised an amplifier? I support the OPs desire to learn wholeheartedly, my only concern was for his safety, given his total lack of basic knowledge, which is surely the concern of many other forum members? I see he has now decided to pass this repair on to someone more qualified, and asks whether he would be better learning on 12v radios. So in answer to the question posed earlier, "Are you happy now?", YES, I AM!!

To answer another question- "How many people do you know who have been killed in this hobby?", I can answer "one". He was my best mate, and he took an extension speaker he had rigged up from a mains radio into the bathroom and put it on the edge of the bath. It fell in, and he was electrocuted. Foolish thing to do? No, he was simply unaware there was any danger, just like the OP was initially, and wasn't to know the radio had a live chassis, because someone had wired the plug wrongly. Through lack of knowledge, pure and simple, he lost his life at seventeen years of age. So am I paranoid about electricity? You bet I am!

Barry

[dave walsh]

I don't think it's odd Bill [post 18]. Invariably they are Record Players!

Dave W

[Grubhead]

Well having had an electric shock, when I was working on a mains switch on a radiogram, which I foolish forgot to unplug, I can tell you that I felt nothing at all. In fact my mind was a blank. So your friend would who died presumably felt nothing at all too.
Of course when I let go that's when the pain hit me!

I never had any real training in electronics, but I never took dangerous risks. For example I would never work on the old TV's, with live chassis, especially the 25KV HT lines! Or the old valve sets with live chassis. Mind you by the time I got into nobody wanted valve radios repairing. And the only thing I learned about valves is that if they don't light up they are gone!

[ben]

I can see both sides of this too.
As is the case with many others on here, I began in electronics before I was in my teens by dismantling equipment from junk shops, jumble sales etc. Along the way, I've had a few close shaves. The first one I remember was after buying, at age 10, what looked like an amplifier from a jumble sale. It has bass-mid-treble controls and oddly, a male 2 pin DIN plug on a captive lead. On trying to connect this to some speakers I got a bit of a belt (In retrospect I assume this was some kind of DJ lighting controller). It's things like that that give you a healthy reminder of the very real dangers of live electricity.

I'd be tempted to say that I'm still here after a few close shaves, 'never did me any 'arm!', but to me that's falacious. It could so easily have gone the other way.

My position is, that a blanket refusal to discuss repairs with uneducated newcomers to electronics is just as dangerous as encouraging them regardless of skill, knowledge or experience. We don't want a scenario where people go off and attempt a 'fix' anyway, unguided, so as not to be a 'quitter' or whatever. There has to be a middle ground. IMHO, that middle ground can be ascertained by establishing the type /design of equipment involved and from there, suggesting that the newcomer proceed or not.

It has been correctly stated that anything connected to the mains is potentially a hazard. However, there are surely degrees of risk. In this case, a record player with low voltage DC amp is never going to be as risky as a live chassis TV or amp, for example. Just like a microwave oven is far more lethal than a mini system, by virtue of what's in there, the design, and currents involved. I think it was right to warn the OP of the dangers, and suggest covering the exposed mains connections with insulating material. As has been said, the other circuits shouldn't pose any great hazard in themselves.

I'd hope that, by focusing on the equipment, we can take a pragmatic line towards our advising and fall into neither reckless encouragement nor hysterical, 'hands-off!' positions.

[Boater Sam]

Two penn'orth.

Seen death by electrocution, went up like a candle.
Been technically dead.
First mains shock at around seven.
Never had a father to help, never had a mentor. Did an apprenticeship, by then I knew as much as the instructors.

In my working days the idiots removed themselves from the gene pool, accidentally, no questions asked.
Now they are preserved in 'elf & Safety', any accidents are festivals for the lawyers. Common sense is anything but.

I will help anyone PROVIDING THEY HEED.
I just don't want to read of a fatality on this or any other forum.

[Croozer]

This is an interesting thread, and I admit to my views being prejudiced by spending much of my childhood on the floor of various TV repair workshops where my dad was employed. (Imagine that today??)I understood the danger of 'live chassis' long before I could read the word chassis. (Incidently the most dire safety warnings issued in said workshop were about not setting the place on fire with the calor gas heaters).

I hadn't appreciated vintage radio existed as a hobby before I encountered this forum, but I did poke around inside consumer electronics from a relatively young age - mainly because I come from a family that's never got the hang of the 'disposable society' .

The most dangerous electric shocks I have had were at work -a desk job in a small office, where as the most junior of the male staff my duties included changing light bulbs. Cracked rubber insulation ment that the fall from the stool I was standing on hurt more than the shock; there wasn't even a thought to enter it in an accident book, and that was the mid 90s.

There is a difference between respect and paranoia. I would hate to discourage Stuboy57 as I applaud his willingness to learn. This is especially true in a world where lack of technical understanding of any sort seems to be emerging. Certain of the youngest staff in my current office were genuinely appalled at the 'danger' I exposed myself to by exposing the guts of an old McMichael transistor radio to change the PP9 battery. Another was afraid to light a gas ring with a match. Yet one of those same individuals got caught out when the 'plug and play' generation of products failed when a Li battery of an e-cig overheated by being subjected to an overvoltage and unregulated current through a cheap charger. Interest in why the smpsu was heating up could have prevented the accident. The irony being I work in the electricity supply industry.

Anything that can be done to encourage curiosity instead of the 'magic black box' acceptance of technology will yield understanding -which in turn will mitigate risk. As long as it can be done safely, through sharing of knowledge-the fundamental strength of this forum.

[joebog1]

The schoolmaster from Pink Floyd's "The Wall" rings loudly here!!
YES we need protect ourselves.
YES we need protect the public.

MOST of us "old boys" got belted a few times.
Telling a newbie DON'T DO IT, is not really what it's about.
If WE DON'T TEACH THEM, who will. Like us, its a dying art!!!

TO ALL CONTRIBUTORS:

AFTER the first belt, WERE you more careful and aware thereafter?

or

Did you need your fat and psychopathic wives
to whip you within inches of your lives?

It's a learning experience, ALL houses in auld prison farm where transportees were shipped, ( Australia) have ELCB,s ( Earth Leakage Circuit Breakers) or so called "Safety Switches" fitted. They are also available as an "extension cord outlet, with safety switch fitted".

I have YET to see that TINY morsel of wisdom presented.

Joe

[julie_m]

There are two very different approaches to the situation where someone wants to do something which could potentially be dangerous if certain precautions are not followed. These are the "Abstinence Only" model, where you simply say "Don't"; and the "Harm Reduction" model, where you say "That can be very dangerous; but if you are going to do it, then it's at least a bit less dangerous if you do it this way". This is based on the idea that some people are always going to do potentially dangerous things such as drink alcohol, have sex, take drugs or poke about inside mains-powered electronic devices, in spite of any dire warnings you may give them; and is the model I shall be unabashedly championing here. After all, this is not the "UK Vintage Radio Leaving Alone As a Non-Functional Display Item Only" forum, nor the "UK Vintage Radio Ripping Out the Original Innards Except the Speaker and Fitting a Bluetooth Receiver and Class D Amplifier" forum.

Although my direct personal experience of these two contrasting approaches to the same problem is in a different area (not radio or electronics repairs), and specifically with young people (who generally have specific problems of their own; such as no good concept of their own destructibility, and they may well be suffering from the hormone-induced psychosis that is puberty) this experience can still be generalised somewhat; after all, people are people, and tend to behave more or less predictably in given situations.

The abstinence-only model relies on the idea that a person is more likely to avoid doing something altogether if they imagine that it is definitely going to have adverse consequences for them, than if they expect to be able to exert some direct influence over the safety or dangerousness of that thing themself. Supporters of this model typically accuse Harm Reductionists of encouraging risky behaviour.

Originally Posted by an Abstinence-Only advovate

If someone does not believe that there is any safe way to open up an old radio, then they are less likely to attempt to do so. It is irresponsible to dilute the deterrent effect of the danger involved in an activity by giving people the false impression of safety. If you tell someone that they will not get hurt if they do it properly, then they are more likely to attempt to do so, and therefore more likely to injure or kill themself.

This neglects that a person who is unaware of a safer way of achieving a particular objective may expose themself to unnecessary danger, if they adopt a more dangerous solution for want of knowing any better. (For instance, someone who has not been taught the best practices for working on high-voltage circuits in case it gave them any ideas about actually working on an old valve radio might be more likely tp attempt measurements in an unsafe manner, if they see evidence of other people working on old radios and nothing terrible happening to them -- but crucially, they do not know why nothing terrible is happening to the others.


Whereas Harm Reductionist reasoning goes more like Do not sugar-coat anything. Simply mention the potential danger, and how best to mitigate it, at the earliest opportunity; and let them decide whether to attempt it at all or give it a miss. So a good Harm Reductionist response to a newbie asking how to go about fault-finding a radio might look something like this:

Originally Posted by a Harm Reduction advocate

First of all, we really need to check the power supply section of the circuit; because if the power supply is faulty, nothing in the rest of the circuit can be expected to work either.

Set your DMM to its highest DC voltage range. Use a crocodile clip adaptor to connect the negative (black) probe to the chassis. Hold the positive (red) probe securely, leaving no bare flesh ahead of the finger guard, and probe onto the positive terminal of C3 (Manufacturer's service data, see here.) Both C3 and C4 are in the same tall, silver cylindrical can, with their negatives joined together. Their positive terminals are marked with a red triangle (C3) and a yellow square (C4).

When you are sure that the probes are making good contact and your hands are well clear of any components or terminals, turn on the power switch. When the valves have warmed up and the meter reading has stabilised, write it down.

Transfer the red probe to the positive terminal of C4, taking great care not to touch anything else, and record the voltage there. Lastly, with the meter probe still on C4+, switch off the power (either at the wall, or using the set's own switch; it does not matter which you use) and time how long it takes for the voltage to drop to zero.

Post your voltage and time readings here and await further instructions. If you have any doubts as to which terminals you should be probing onto, post some photographs of the interior of the set.

I'll now attempt to reverse-engineer this hypothetical procedure and explain what makes it good Harm Reduction:

1. We have already looked at a wiring diagram, and in this case it was supplied in the manufacturer's own manual. There is nothing exactly wrong with Trader or similar service sheets; but by dint of being aimed squarely at experienced radio and TV repairers, they can be very terse for omission of obvieties.
2. There is a lot of description, but we are only actually asking the poster to take three measurements: two voltages and a time. In future, we probably don't need to go into such detail over the proper way to hold a test probe.
3. Another reason for starting with the PSU section is, Human Factors. The PSU is where we are likely to find the highest voltages in a set. Measuring these voltages shows the poster exactly what they are up against; doing it without getting hurt will give a psychological boost (there was over 300 volts in that capacitor, but I am still in one piece because I was being careful) and convince them that they are not going to electrocute themself if they stick to the instructions.
4. We leave the set in a known, safe state pending analysis of the results.
5. The next person who comes along will be able to determine whether these readings are good, or whether something downstream is drawing excessive current.

That is one way to make measuring some of the most dangerous voltages in a set, as safe as possible.

It's important not to sound condescending or draconian, even although you are expecting people to follow your instructions to the letter. The purpose of this is not to lay down some sort of heavy authority trip on anyone, but to establish certainty about the measurements being made. The Newbie is in a position of having to do things, possibly without a full understanding of them. That's OK, because we're doing the understanding bit for them first, then explaining it back to them so that they can understand it; but in order for that to work, they have to carry out the actions exactly as told, and report the results exactly as they see them, because that is what we are expecting. Nonetheless, there should always be a reason for making a particular measurement, or for doing something a particular way, even if it is not obvious straight away. If you mention two alternative ways of doing something, people might at least feel they have some choice in the matter.

The learner, in their turn, has certain responsibilities. Most importantly,

1. Follow the instructions exactly as given (*)
2. Leave anything alone that you were not specifically asked to touch,
3. If unsure, do not guess -- ask someone.

(*) This confers an additional responsibility on respondents: Make sure that any instructions you give will be as safe as possible if followed exactly. For instance, do not advise anyone Lick one of the white wires with your tongue. If you do not feel anything, leave the other white wire alone.

Also, don't pick fights in front of people. If another poster has asked a newbie to do something that you consider dangerous, don't berate them in the forum. You can post an explanation of why you think it might not be the safest approach, and -- if possible -- provide an alternative method to achieve results compatible with the original, less-safe method; but it might be better just to say "hold on for now, don't touch anything just yet" and PM the other poster. They probably will have the thread open in a tab of its own that they can keep refreshing anyway, but a private message might be more appropriate for what you have to say; something like

Originally Posted by someone in a moment of righteous anger

Hey , that was a really smart move asking a n00b to measure anode-anode like that with a cheapo Chinese test meter. They would have been way safer measuring A1-chassis and A2-chassis and adding them together, and more likely them and the meter still be in one piece now, and the difference could have been useful to know as well as it would show up a possible problem with shorted turns in one half of the secondary winding.

doesn't really belong in the public forum. On the other hand,

Originally Posted by a contrite original respondent

Hi, did you do those tests on the HT circuit yet? If not, I think there is a safer way. Instead of red probe to V5 pin 1, black probe V5 pin 7, measure as follows: Set meter to highest AC volts range. Connect black probe chassis, red probe to V5 pin 1; call this V1. Move red probe to V5 pin 7; call this V2. Post both AC readings. The sum V1 + V2 will be equal to the originally-requested reading between V5 pins 1 and 7, but this way of measuring it is safer as it only involves lower voltages. Then, continue as before: disconnect red probe, set meter to highest DC volts range and measure the voltage at V5 pin 3 (black probe still clipped to chassis). Post this reading.

NB: If there is more than about 10 V difference between V1 and V2, this could indicate a problem with the transformer.

looks a lot better. It's less confusing than being told two different things, and it shows that we're all human. Mods can also do a tidy-up job (even of the "chuck in a lighted match and run" variety) for the benefit of anyone searching in future.