Author Topic: My trusty Quad 405 MK 1 is fixed!  (Read 1849 times)

Offline handsome

Re: My trusty Quad 405 MK 1 is fixed!
« Reply #15 on: December 23, 2017, 07:32:44 PM »
if you up to it rather get a circuit diagram of the amp with the voltages marked, then use a multimeter to check the voltages at all the points. the problem should become glaringly obvious from the discrepancy between expected and measured voltages. those Quads are class B amplifiers so there should be no current in the output stage. the fact that the heatsink gets red-hot means something attached to said heatsink is passing way too much current.....

Offline skollie

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Re: My trusty Quad 405 MK 1 is fixed!
« Reply #16 on: December 24, 2017, 12:17:24 AM »
Happy Merriness to you too Skollie ! Don't kill yourself by feeling around that amp with latex gloves , rather get the other Leak fixed .  ;D

All my Leak stuff has gone to a good home - 13 Hof. You probably referred to the two Pye HF25's. One is completely finished and doing very good things. The other awaits my recovery from the big C - not sure if this will happen though.

skollie
« Last Edit: December 24, 2017, 12:47:15 AM by skollie »
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Offline skollie

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Re: My trusty Quad 405 MK 1 is fixed!
« Reply #17 on: December 24, 2017, 12:45:26 AM »
if you up to it rather get a circuit diagram of the amp with the voltages marked, then use a multimeter to check the voltages at all the points. the problem should become glaringly obvious from the discrepancy between expected and measured voltages. those Quads are class B amplifiers so there should be no current in the output stage. the fact that the heatsink gets red-hot means something attached to said heatsink is passing way too much current.....

Thanks for your thoughts, Handsome. Almost the entire 405's casework is aluminium heatsinks. in addition to the two boards' own substantial heatsinks. Being aluminium, they cannot get 'red hot' which I did not write. They get so hot one cannot touch them. The right channel is fine but the faulty left channel's heatsink coupled very firmly to the casework generates so much heat that a lot of heat is also transferred to mainly the top and front of the amps casework on the right side.

I myself fitted the 1st set of 4 new DaDa recommended transistors together with all their mica strips and paste but the left channel kept blowing one of the two fuses on the board.



I then contacted the friend for some assistance and bought another complete set of transistors which my ex Telkom tech fitted. When the former faulty and silent left board was fitted by him, the amp played on both channels and obviously, no blown fuse.

The second set of recommended transitors was supplied to him with all new insulating strips and screw insulators. I rigged the amp with a pre-amp, and a pair of 8ohm speakers and this was when the left channel's heating up started but now playing. I left it on for probably less than 5 minutes when I discovered the heating up and switched off immediatelly

It was the next day, before I wanted to bolt the case back on, that I looked closely at the board and discovered that one of the small, black square transistors had its heatsink 1mm away from the board's heatsink. I fixed this problem with identical new nut and bolt, thinking I had found the problem. To be sure, this time I left it playing on both channels for about half hour and this time, I found the very hot heatsinks generated from the left channel board.

I will inspect the tech's work tomorrow much more closely incase something else has been left out causing what appears to be a dead short somewhere. I'm just surprised that the 5th fuse at the amp's back didn't blow as all fuses have their correct ampere ratings.

skollie
« Last Edit: December 24, 2017, 12:49:43 AM by skollie »
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Offline fredeb

Re: My trusty Quad 405 MK 1 is fixed!
« Reply #18 on: December 24, 2017, 02:45:06 AM »
All my Leak stuff has gone to a good home - 13 Hof. You probably referred to the two Pye HF25's. One is completely finished and doing very good things. The other awaits my recovery from the big C - not sure if this will happen though.

skollie

Sorry , yeah , I meant the PYE HF25's . There is a man who is a member of this forum who is an oncologist whom firmly believes that what helps prevent the proliferation of the big C is an alkali body . He reckons that lots of fresh lemons will help . Drink water with lemon juice , keep lemons in your freezer and grate the rind into the food you cook , basically do lemon whereever possible .
I'd also look at a macrobiotic food chart to see what food types react with the body so as to make it more alkili and which make it more acidic . Basically try and keep your system more alkali than acidic . This and whatever treatment you are following .

https://www.webmd.com/diet/macrobiotic-diet
« Last Edit: December 24, 2017, 03:07:28 AM by fredeb »
...evolution is the gradual development and stratification of progressive series of wholes, stretching from the inorganic beginnings to the highest level of spiritual creation.
Jan Smuts

Offline Trompie67

Re: My trusty Quad 405 MK 1 is fixed!
« Reply #19 on: December 24, 2017, 03:41:27 AM »
Sorry , yeah , I meant the PYE HF25's . There is a man who is a member of this forum who is an oncologist whom firmly believes that what helps prevent the proliferation of the big C is an alkali body . He reckons that lots of fresh lemons will help . Drink water with lemon juice , keep lemons in your freezer and grate the rind into the food you cook , basically do lemon whereever possible .
I'd also look at a macrobiotic food chart to see what food types react with the body so as to make it more alkili and which make it more acidic . Basically try and keep your system more alkali than acidic . This and whatever treatment you are following .

https://www.webmd.com/diet/macrobiotic-diet

That member should retire from oncology & go full time into quackery. Our kidneys regulate the pH of our bodies, not our diet.
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Offline Family_Dog

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Re: My trusty Quad 405 MK 1 is fixed!
« Reply #20 on: December 24, 2017, 08:40:44 AM »
Quote
It was the next day, before I wanted to bolt the case back on, that I looked closely at the board and discovered that one of the small, black square transistors had its heatsink 1mm away from the board's heatsink. I fixed this problem with identical new nut and bolt, thinking I had found the problem. To be sure, this time I left it playing on both channels for about half hour and this time, I found the very hot heatsinks generated from the left channel board.

Skollie, did you use insulation when doing this, i.e mica and nylon washers?


-F_D



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Offline skollie

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Re: My trusty Quad 405 MK 1 is fixed!
« Reply #21 on: December 24, 2017, 12:05:59 PM »
Sorry , yeah , I meant the PYE HF25's . There is a man who is a member of this forum who is an oncologist whom firmly believes that what helps prevent the proliferation of the big C is an alkali body . He reckons that lots of fresh lemons will help . Drink water with lemon juice , keep lemons in your freezer and grate the rind into the food you cook , basically do lemon whereever possible .
I'd also look at a macrobiotic food chart to see what food types react with the body so as to make it more alkili and which make it more acidic . Basically try and keep your system more alkali than acidic . This and whatever treatment you are following .

https://www.webmd.com/diet/macrobiotic-diet

Hi FredeB and Trompie

Apologies for the OT.

Since I shuffled out of hospital after spending 6 weeks there and 5 radiation treatments but no chemo poison,
I have tried to rehabilitate myself as best as I can. There was a massive heap of admin stuff to attend to  after my wife's untimely passing, I fitted 4 new LED floodlamps to replace the old halogen items, been clambering over rafters in my roof for the LED's wiring, cast new "33"'s to replace my stolen house number and put them up myself. My latest 'achievemment'was to put a 5th LED floodlamp 4metres up above my garage doors and many other things around the house which require strong legs and arms.

And trying to fight ever increasing crime in my street from individuals stealing bits off the front of my house.

So forgive me if I blow my own vuvuzela a bit as I was sent home with a Zimmerframe and told to go into a "home". Like bloody hell I'll do that unless the present situation with severe nerve damage to my legs and feet worsens.

Bro' Jan and I returned the Zimmer frame after the first week at home in February as it was taking up space in my workshop and the contraption reminded me daily of my present muscular feebleness. A nice boss I had many years ago gave me an 'alpen stock' which I never used but this has now come in very useful as I use it when walking in the street.

Oh, and I now have a "Disabled Driver" sign about which I still have mixed feelings. Joke: First time issue at Gallows Hill Traffic Dept the thing was valid for ONE DAY ;D in error. Then I had to go back to have it reissued for 3 years.

The shocking and sad thing I've experienced when walking outside my premises, is that most vehicle drivers these days don't give a damn for an old guy crossing a road with a stick. Some even accelerate or make illegal U-turns when I cross the road.

After coming home in February, my brother and I spent probably hundreds of hours not so much to find cancer cures but to find ways to recover as much as possible and especially to regain energy.

Bro' Jan picked-up something about blue berries and I bought these regularly but it made no difference to the symptoms of this disease. My youngest brother offered two 'tips' as so-called cures - cannabinol (dagga) oil and pomegranite juice but had no positive effect.

Dagga is not for me but I bought many 2l bottles of adulterated pomegranate juice - not for a 'cure' but for energy. Of course this didn't work either.

Neither does large boxes of Vitathion and many cans of Replace at lots of $$. In fairness to the Replace stuff, I did regain the 8kg mass loss.

I do go to hospital every few weeks for checkups and consult my GP inbetween hospital visits but this is heavy on my $$ resources.

So here you are I'm not tempted nor intending to go wild goose chasing after cancer cures. When you gotta go, you gotta go ;D Some time next year, I will ask the oncologist if physio therapy will help a bit with my damaged leg and feet nerves and even contacted Tim Noakes to ask if there is a measurably way to get some credible indication of improvement or not of leg and feet control. The answer was "NO!".

Anyway, enough of this.

@ F_D

The original insulators in the 405 were mica items. When I fitted the fits set of transistors, I worked very carefully and only found one original with a chip out. I discarded the damaged mica item and replaced all of them with new grey items as they didn't stock mica items. I don't know what the new grey items were made from but Communica assured me they are legit replacements for mica. But of course they can tell one anything with a straight face. I also bought new screw shaft insulators as many of the originals were brittle.

I don't want to cast aspersions on my helper as he is technically much more knowledgeable than I am but we are 50/50 with soldering and desoldering skills. And he works as tidily as I do.

This morning I have to finished work on my vandalised front gate lock. If there is time left, I will do a much closer inspection as my helper fitted the new second lot of transistors and maybe something was left out.

Thanks for reading and a Merry Christmas and a healthy 2018 and beyond to ya all.

skollie



 
« Last Edit: December 24, 2017, 12:39:17 PM by skollie »
If you don't like my principles, I have others - Groucho Marx

Offline Trompie67

Re: My trusty Quad 405 MK 1 is fixed!
« Reply #22 on: December 24, 2017, 02:17:28 PM »
Skollie - my apologies for derailing your thread.

You sound very much like my late Mother - strong willed & determined. Respect.

I have a passionate hatred (yes, it's that strong) for all the charlatans & purveyors of false hope through quackery for those living with cancer.

I have watched first my uncle (when I was a teenager) & both my parents (between 2000 & 2013) deal with, treat, and in one instance through desperation succumb to quackery & charlatans. I've personally gone and collected monies paid for promised cures and benefits from some of these scum, and in one instance the POS was hospitalised & then arrested for fraud.

That said, I also have no great affection for oncologists either. I've watched a "world renowned" and highly respected oncologist try all and sundry, including "maintenance doses" on my late Mother - maintenance means she had treatment once a month as her markers were elevated, no other proof of a relapse bar elevated markers. After 18 months of different maintenance concoctions he told us with utter contempt that there were no more options for her, he'd done her a favour & kept her alive for an extra 18 months & she must go home & prepare to die within 3 months. Washed his hands of her. I have no words to describe how I despise this man.

Other oncologists were appalled at the "maintenance" & his attitude. He still practices & caused the death of my wife's aunt through radiation treatment - literally burnt her colon so badly through excessive radiation she died due to septicemia within a week of starting his "treatment plan".

In a nutshell: Be strong, be true & choose wisely.

Mods/Admin - feel free to delete if deemed necessary.
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Online Katji

Re: My trusty Quad 405 MK 1 is fixed!
« Reply #23 on: December 24, 2017, 03:10:46 PM »
(Sorry about the further off-topic, I'll limit it, I'll ask skollie about the React weight gain stuff in PM.)
There is a man who is a member of this forum who is an oncologist whom firmly believes that what helps prevent the proliferation of the big C is an alkali body . He reckons that lots of fresh lemons will help . Drink water with lemon juice , keep lemons in your freezer and grate the rind into the food you cook , basically do lemon whereever possible .
Who is it? Maybe he could advise me.  I had NH Lymphoma a few years ago, the oncologist haemotologist stopped it very quickly and effectively, but he's not into talking about [possible] contributory factors and so on.

PS: @skollie, please check your PMs.
« Last Edit: December 24, 2017, 03:29:58 PM by Katji »

Offline fredeb

Re: My trusty Quad 405 MK 1 is fixed!
« Reply #24 on: December 24, 2017, 03:25:44 PM »

Thanks for reading and a Merry Christmas and a healthy 2018 and beyond to ya all.

skollie

It sounds like you won't give up the will to live easily Skollie , and that's the most important thing .

And remember to put a fan next to you to blow away those nasty solder fumes .

A very Merry Xmas to you man !
...evolution is the gradual development and stratification of progressive series of wholes, stretching from the inorganic beginnings to the highest level of spiritual creation.
Jan Smuts

Offline skollie

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Re: My trusty Quad 405 MK 1 is fixed!
« Reply #25 on: December 24, 2017, 04:56:12 PM »
I appreciate your comments gents. Maybe the mods could split the thread about quackery  to somewhere in Open Talk and change the subject of "My Quad 405 is Still not fixed" and leave it where I started it?

There are a few things on my mind about "Skollie's further experiences during 2017" but no slagging off pf professions or snot en trane in Open Talk? For instance that one can almost spend years reading about 'cures' or dead cert regaining of lost energy?

Or shut the thread, it's Christmas afterall :D

Btw, aren't lemons acidic? How does one change a body to being alcalic by consuming acidic lemon?

skollie
If you don't like my principles, I have others - Groucho Marx

Offline peterc

Re: My trusty Quad 405 MK 1 is fixed!
« Reply #26 on: December 24, 2017, 11:26:57 PM »
Hi Skollie

As hansome said, comparing the 2 channels DC voltages should find the area of concern.

Do you have a multimeter? If not, I'm sure your friend has.

The idea is to measure the DC voltages at each and every component leg on both channels and see where they differ.

The other thing to do is to check for high frequency oscillation on the dodgy channel, This needs an oscilloscope, maybe your friend has one still?

Good luck and Merry Xmas.

Peter

Offline skollie

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Re: My trusty Quad 405 MK 1 is fixed!
« Reply #27 on: December 25, 2017, 02:24:08 AM »
Hi Skollie

As hansome said, comparing the 2 channels DC voltages should find the area of concern.

Do you have a multimeter? If not, I'm sure your friend has.

The idea is to measure the DC voltages at each and every component leg on both channels and see where they differ.

The other thing to do is to check for high frequency oscillation on the dodgy channel, This needs an oscilloscope, maybe your friend has one still?

Good luck and Merry Xmas.

Peter

Hi PeterC

I have a couple of multimeters including Fluke and I also have a good 2-channel Isotech 35MHz oscilloscope.

These tools I use for mc cartridge making and my diagnostic knowledge of amplifiers are just about zero. I can make old amps look new again and can repair or replace faulty bits if I can physically SEE the problem. Amp theory and repair is not in my limited knowledge of electronics.

The friend helping me is a retired Telkom test equipment technician and repairer and he has an abundance of very expensive Fluke test gear coasting many thousands of $$.

It is interesting you mentioned HF oscillation. My friend also mentioned the same  possibility which we will check out after the holidays.

All I will do before he returns to the job, will be to switch on the amp and let it play for 5 mins or so and then switch off and unplug  and then 'feel' the board to determine thje area which cvaued the massive overheating a few days ago after I let it play for +-25 minutes. If it is HF oscillation, this excercise will probably be futile as I'm guessing all components on the board will be equally hot.

Thank you for your advice  & a very Merry Christmas and the same for 2018 and beyond.

skollie
If you don't like my principles, I have others - Groucho Marx

Offline JANNAS

Re: My trusty Quad 405 MK 1 is fixed!
« Reply #28 on: December 25, 2017, 07:02:42 AM »
Skollie, what I would do is to first check  DC offset at the speaker terminals and the bias circuit of the faulty channel. The bias is not adjustable, so there will be a faulty component,eg diode, resistor or transistor, but I suspect the vas circuit. DIY audio have a lot of info on this  "current dumping" amp. Oscillation should heat up the zobel resistor as well, and off course I will connect a bulb tester in series with the live to act as current limiter just to be safe while testing. Have a merry xmas and I pray for your complete healing !! :thumbs:

Offline skollie

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Re: My trusty Quad 405 MK 1 is fixed!
« Reply #29 on: December 26, 2017, 03:55:40 AM »
Hi Jannas

Thank you. Of course similar wishes to you and yours as well.

I have bioth a bulb terster 'de Luxe' diy'ed and a recently built Philips variac which I also built from anm item bought from a forum member in PE.

I have a few things to attend to but in a very few days, we'll return to my amp. I have also done DC offset testing on a large Kenwood amp I have.
I'm sure by next week we'll have a Eureka moment.

REgds

skollie
If you don't like my principles, I have others - Groucho Marx