I used to use an ordinary pencil eraser to clean those lower pc board connectors. Worked like a champ. Thanks for another troubleshooting venture, Dave!
Hello Wibo here from the Netherlands, hope you are well. Love your video of the M2000 , I have the same and from the video I learn a lot of this fantastic power amp. Thanks a lot 👍
Percussive diagnostics are very useful. Always give it a whack. I found and fixed bad solder points in a subwoofer by tapping on the circuit board with a bamboo chopstick!
Yeah I agree. BUT.. You must tap around the section that has a bad connection VERY SOFTLY because if you tap agressively you will end up removing the 'oxydation' if there are any .. The contact will catch back FOR A WHILE.. Then the problem comes back after a couple of days (oxydation rebuild). Taping softly will show the problematic area without bringing back the connection.
The M2000 was a fairly pricey amp back around the late 70's. The next model up would've been the M4000 which was pretty hefty both price and weight wise. I've a M2000 along with two L100 Integrated amps and a T-110 tuner. Very solidly made, attractive and performs well. One of the L-100's remains in protection mode which I must address in due time, it's probably the connectors that need cleaning and circuit board touchups like you're doing. Good to see the insides of this unit, thank you!
Great video, Dave!, don't worry about those snowflakes!!, sometimes you have to use what I call the fonzi touch to help find /troubleshoot problems!! Lol 😆
Seeing those edge connectors reminds me of some old HP telecommunications testing gear I had. Seeing all of the very high quality parts in those HP instruments makes me wonder how great a HP made amplifier would have been from that time - 60's - 70's ish. Of course, the price would have been at second mortgage levels.
As soon as that buzzy hum sound was heard, it sounded EXACTLY to me like two different guitar amps that had the big filter cap on one rail had a cracked solder joint. That SAME buzz. That's one beastly amp.
Mmm hand drawn Luxman circuitry. The first amp I fixed was a Luxman L30. One issue was intermittent crackles... Diagnosed and isolated via the whackamole method. Luxmans seem to enjoy this. P.s. The small signal transistors fail because the had silver tinned legs. The silver oxidises up into the wafer.
35:20 ...and they call that a protest there in Canada? A performance artist in Moscow stripped naked and nailed his scrotum to the cobblestones of Red Square as some sort of protest (Nov 2013). lol, I wonder if a couple large fender washers under the head of that nail would have provided a better "grip" since the guy got picked up and hauled off anyway... IDK, maybe a broken pelvis is preferable. BTW, if "planned" energy shortages happen within the year or two, chopping down some wood to heat your home in the winter might be a necessary life saver, even for those tree huggers. The OEM soldering was pathetic back in the good old days even with that generous application of leaded solder. Oxidized component leads and lousy flux provided lots of "service opportunity". Great care, thorough repair job, clear audio with perfect video close ups all make it a joy to watch you work!
It's not so much just chopping trees it's chopping the old growth forests that they have an issue with. The problem comes from the fact though that these old growth forests are on indigenous lands and the first Nation people have self-governance of those said lands. They can do what they please and the government is not going to interfere.
@@12voltvids Thanks for the background info. I like the sound of self-governance and land ownership/management and hope their foresters can nurture nature responsibly, maybe with fire-breaks and clear out dry underbrush, etc. Take care all.
Here by me protests are so common there is a spot in the morning news traffic report for them with locations to avoid. However normally involves burning tyres on the road and stoning cars.
Plug-in cards (aka “works-in-drawer”) was almost a rage back in the day .. until it was discovered that heat/expansion cycles would cause them to back their way out of the slot/connector, (Did you ever see a raised nail on the outside of a house). Hence, a locking mechanism is needed. Also, the edge connectors need to be very robust …
The malfunctioning amp may not know the words, but it can certainly carry a note at 60 Hz... And, yeah, you have to give it a knock sometimes. When everything is normal, it shouldn't do anything but work even when giving it a few whaps. But if there are bad connections or bad solder joints, giving it a few whaps can help you to reveal problems and even the general vicinity of the fault. It's not like you're taking a sledgehammer to it.
Hand drawn with pen on paper, then photographed onto a transparency for use to expose the photoresist. First one was likely hand drawn, direct on the copper, with India ink, left to dry then etched. Then when working was copied to paper again.
LOL, I got a similar connection fault somewhere in a cassette deck Im working on and also have given it a bit of the ol percussive maintenance to test it out.
I've seen a lot of square cross section pins cause trouble, a black line is always there where the opposite contact touches the pin. dampness is my guess. Those transistor sockets bother me, I'm sure they weaken over the years. But i so like the easy changing of the outputs.:-D I am no lover of wire wrapping on square pins, damp buggers up the connection. Dam i'm moaning again lol.
Smacking is brilliant diagnostic technique, haven't even finished the video yet but sure does imply a connection problem or dry solder joints perhaps, I thought filter caps might have been bad first off I'll kepp watching now to see how it goes lol first impressions though I like your style 😂😊 Oh wow gorgeous fucking amp 🤤 had an l200 years ago from tip shop just replaced caps and couple of resistors I could see were burnt out works beautifully till I over drove shitty tip shop speakers and blew it beyond my knowledge of fixing at the time 😂
Shame the top of that unit is scratched up my Luxman is 50watts RMS per side! it was funny how you talked about the Zenith Tv's with those plug-in boards that was a good set other than that issue I did Zenith warranty work in the day .
Well those chroma color too did have a good picture when they worked. But boy did they have problems that four lead capacitor would blow up all the time triplers failing left right and center and of course those plug-on modules that caused all those intermittent problems that everybody just despised. You'd fix it send it back to the customer a month and a half later it's back with a different intermittent fault you'd fix that you send that back out two months later it's back with a different intermittent fault you'd reseed everything again we were unplugged all those connectors clean up the pegs that they are on tighten down the springs push them back on be perfect in the shop send it out six months later it was back with another intermittent problem then people would get mad tell you you're incompetent that you can't fix it and the problem was caused by the modules. I remember getting one in once that some jackass had soldered all the modules down to the pins well that was great module didn't have a failure bad connections but when a module failed and you had to remove it and it was soldered down well there was no way to really get the module out other than break it out and then unsolder all the individual pins and then you couldn't send the defective one back as you remember seeing if you used to take the modules back and rebuild them.
Greetings from New Zealand. Yes, the service industry cannot afford time consuming repairs, the customer wants their stuff fixed at a reasonable price else it gets dumped. To run a successful repair shop, any shortcut to find the fault is used, so anything that works is valid. The actual repair is the easy part of the process, finding the fault is the expensive bit... I am usually informed that it was working yesterday, so there wont be much wrong with it, and its likely just a "wire off".
Yes likely bad connections on those tinned connectors, they get grumpy with age. The voltage might be already set to 120VAC, probably by the importer, to get the regulatory sticker, so they just did not bother with changing the rear panel sticker. 61V on the 80V capacitor is about right for the rails anyway, and that transformer certainly never has run warm in any way.
I can tell you’re from around my age. My “elders” used to give me s**t if I banged on something to troubleshoot or if I “Easter egged”. Even if it was cheaper. The NASA crowd and older, they always wanted to know the exact cause.
My elsers were the ones that taught me to rattle and smack everything. You should have see what the engineers did at the TV station I interned at. I am surprised the old CEI280 cameras even worked at all considering the abuse the engineers and crew gave them. Bad connections everywhere and they were generally fixed with a smack on one side or the other.
I started work in about 75 in the Houston area. Worked with a lot of Viet Nam era ex military technicians and lots of ex NASA technicians. Those guys were crazy strict. Also started working on geophysical electronics - cost a pretty penny. Not to say there weren’t a few properly timed percussive taps used every now and then.
Percussive maintenance is all well and good for troubleshooting, but I don't like to rely on it during use. I would like to know the cause of the fault as well, and then fix it, rather than making a habit of pounding on something until it works, and then hoping it continues to -- because it probably won't, and then I'll want to pound on it out of frustration. FWIW, I definitely don't want to hear someone on a space shuttle telling me, "oh it does that -- just smack it until it starts working again." Naw, man! This isn't a shop radio! Fix it! hahah
@@nickwallette6201 Well tapping intermittent is how we find the fault. It allows localizing the fault. Once the area is found then move to the plastic spudger to lightoy scrape the board or probe individual connections to see if the fault reoccurs and then go in and fix the problem. With the cameras that were always faulting at the TV station they were beat up so much because the engineers never were able to fix the problem. They would work on them, and then in the next production, right in the middle of a shoot one of them would start acting up. We would stop tape, smack the camera a few times to get it working and then continue, and the engineer would be back on it again and not fix it.
@@12voltvids I'm with you all the way on finding faults, and I get sometimes you do what you have to do when you can't find an intermittent fault, and have to keep using something anyway. What bugs me is people who put up with stuff that can be easily fixed, like a dodgy connector, or bad cable, or something like that. :-) Smacking is a temporary fix!
Tapping on components to test for loose connections is a perfectly valid diagnostic method. Dragging chassis/faceplates/heatsinks around on your bench potentially causing scratches and worn edges makes me cringe.
I don't drag them around. I lift the edge with any edges that could get scratched. In this case the unit is already beat up. If i have a piece that is in immaculate condition I will either put a rag down under it or stick tape on the edge during service. Watch when i move things. I lift the front side up.
I get annoying posters on my Turntable Guy channel all the time telling me what to do, what I've done wrong, etc, etc. It's best to ignore them, mute them, ban them. Putting a snowflake message on the video is just going to get people to turn the video off. The term snowflake brings with it a lot of baggage.
The music i use is royalty free and I have the license to use it. Quite often the radio inside the house gets picked up by the microphone but it is so low in the background that it doesn't register and if it did I would just mask it with fan noise.
I used to use an ordinary pencil eraser to clean those lower pc board connectors. Worked like a champ. Thanks for another troubleshooting venture, Dave!
I still do that john.
Great job. Cold solder joints from prior repairs. Reflow all solder connections to fix intermittent fault. great video
Tapping "gently" the old tube TV with a rubber mallet got me into electronics for first time.
Hello Wibo here from the Netherlands, hope you are well. Love your video of the M2000 , I have the same and from the video I learn a lot of this fantastic power amp. Thanks a lot 👍
Percussive diagnostics are very useful. Always give it a whack. I found and fixed bad solder points in a subwoofer by tapping on the circuit board with a bamboo chopstick!
Yeah I agree. BUT.. You must tap around the section that has a bad connection VERY SOFTLY because if you tap agressively you will end up removing the 'oxydation' if there are any .. The contact will catch back FOR A WHILE.. Then the problem comes back after a couple of days (oxydation rebuild). Taping softly will show the problematic area without bringing back the connection.
The M2000 was a fairly pricey amp back around the late 70's. The next model up would've been the M4000 which was pretty hefty both price and weight wise. I've a M2000 along with two L100 Integrated amps and a T-110 tuner. Very solidly made, attractive and performs well. One of the L-100's remains in protection mode which I must address in due time, it's probably the connectors that need cleaning and circuit board touchups like you're doing. Good to see the insides of this unit, thank you!
Great video, Dave!, don't worry about those snowflakes!!, sometimes you have to use what I call the fonzi touch to help find /troubleshoot problems!! Lol 😆
Those caps look like bombs waiting to go off😂. Love the channel.
Seeing those edge connectors reminds me of some old HP telecommunications testing gear I had. Seeing all of the very high quality parts in those HP instruments makes me wonder how great a HP made amplifier would have been from that time - 60's - 70's ish. Of course, the price would have been at second mortgage levels.
@Kent Teffeteller That's awesome! HP always used the best parts back in the day. I wonder if any of those are still around.
As soon as that buzzy hum sound was heard, it sounded EXACTLY to me like two different guitar amps that had the big filter cap on one rail had a cracked solder joint. That SAME buzz. That's one beastly amp.
Mmm hand drawn Luxman circuitry. The first amp I fixed was a Luxman L30. One issue was intermittent crackles... Diagnosed and isolated via the whackamole method. Luxmans seem to enjoy this.
P.s. The small signal transistors fail because the had silver tinned legs. The silver oxidises up into the wafer.
Beautiful amp 👍
very nice and well built amplfier
35:20 ...and they call that a protest there in Canada? A performance artist in Moscow stripped naked and nailed his scrotum to the cobblestones of Red Square as some sort of protest (Nov 2013). lol, I wonder if a couple large fender washers under the head of that nail would have provided a better "grip" since the guy got picked up and hauled off anyway... IDK, maybe a broken pelvis is preferable.
BTW, if "planned" energy shortages happen within the year or two, chopping down some wood to heat your home in the winter might be a necessary life saver, even for those tree huggers.
The OEM soldering was pathetic back in the good old days even with that generous application of leaded solder. Oxidized component leads and lousy flux provided lots of "service opportunity".
Great care, thorough repair job, clear audio with perfect video close ups all make it a joy to watch you work!
It's not so much just chopping trees it's chopping the old growth forests that they have an issue with. The problem comes from the fact though that these old growth forests are on indigenous lands and the first Nation people have self-governance of those said lands. They can do what they please and the government is not going to interfere.
@@12voltvids Thanks for the background info. I like the sound of self-governance and land ownership/management and hope their foresters can nurture nature responsibly, maybe with fire-breaks and clear out dry underbrush, etc. Take care all.
Here by me protests are so common there is a spot in the morning news traffic report for them with locations to avoid. However normally involves burning tyres on the road and stoning cars.
Why do people have an issue with diagnosing by tapping... Lol how are else are you supposed to find intermittent connections
Thanks for another info vid Dave. Would applying di-electric grease be a good or bad idea on those multi-pin connections ?
Nice modular amp from past....First time in hifi slogan high end used on M6000 in 1976...Tim de Pavaricini's child
Plug-in cards (aka “works-in-drawer”) was almost a rage back in the day .. until it was discovered that heat/expansion cycles would cause them to back their way out of the slot/connector, (Did you ever see a raised nail on the outside of a house). Hence, a locking mechanism is needed. Also, the edge connectors need to be very robust …
Ala S-100
These amps were absolute beasts.
Just wait till you see what i am picking up today. You want to talk about a beast.
I noticed the main outputs are on semi made in Mexico The original Japanese probably toasted from over-voltage
The malfunctioning amp may not know the words, but it can certainly carry a note at 60 Hz...
And, yeah, you have to give it a knock sometimes. When everything is normal, it shouldn't do anything but work even when giving it a few whaps. But if there are bad connections or bad solder joints, giving it a few whaps can help you to reveal problems and even the general vicinity of the fault. It's not like you're taking a sledgehammer to it.
😀
Those old circuit boards are kind of alien space ship looking.
That is a pretty typical board layout pattern.
Hand drawn with pen on paper, then photographed onto a transparency for use to expose the photoresist. First one was likely hand drawn, direct on the copper, with India ink, left to dry then etched. Then when working was copied to paper again.
The beauty of discreet components vs. today's all-in-one ic's.
LOL, I got a similar connection fault somewhere in a cassette deck Im working on and also have given it a bit of the ol percussive maintenance to test it out.
I've seen a lot of square cross section pins cause trouble, a black line is always there where the opposite contact touches the pin. dampness is my guess.
Those transistor sockets bother me, I'm sure they weaken over the years.
But i so like the easy changing of the outputs.:-D
I am no lover of wire wrapping on square pins, damp buggers up the connection.
Dam i'm moaning again lol.
Smacking is brilliant diagnostic technique, haven't even finished the video yet but sure does imply a connection problem or dry solder joints perhaps, I thought filter caps might have been bad first off I'll kepp watching now to see how it goes lol first impressions though I like your style 😂😊
Oh wow gorgeous fucking amp 🤤 had an l200 years ago from tip shop just replaced caps and couple of resistors I could see were burnt out works beautifully till I over drove shitty tip shop speakers and blew it beyond my knowledge of fixing at the time 😂
Shame the top of that unit is scratched up my Luxman is 50watts RMS per side! it was funny how you talked about the Zenith Tv's with those plug-in boards that was a good set other than that issue I did Zenith warranty work in the day .
Well those chroma color too did have a good picture when they worked. But boy did they have problems that four lead capacitor would blow up all the time triplers failing left right and center and of course those plug-on modules that caused all those intermittent problems that everybody just despised. You'd fix it send it back to the customer a month and a half later it's back with a different intermittent fault you'd fix that you send that back out two months later it's back with a different intermittent fault you'd reseed everything again we were unplugged all those connectors clean up the pegs that they are on tighten down the springs push them back on be perfect in the shop send it out six months later it was back with another intermittent problem then people would get mad tell you you're incompetent that you can't fix it and the problem was caused by the modules. I remember getting one in once that some jackass had soldered all the modules down to the pins well that was great module didn't have a failure bad connections but when a module failed and you had to remove it and it was soldered down well there was no way to really get the module out other than break it out and then unsolder all the individual pins and then you couldn't send the defective one back as you remember seeing if you used to take the modules back and rebuild them.
Greetings from New Zealand. Yes, the service industry cannot afford time consuming repairs, the customer wants their stuff fixed at a reasonable price else it gets dumped. To run a successful repair shop, any shortcut to find the fault is used, so anything that works is valid. The actual repair is the easy part of the process, finding the fault is the expensive bit... I am usually informed that it was working yesterday, so there wont be much wrong with it, and its likely just a "wire off".
Well today it’s a throw away nation
Did you yama ' hop that ladder protestor ?
Power supply thermistors, perhaps?
On this? No.
Nice work saving a quaity unit.
Yes likely bad connections on those tinned connectors, they get grumpy with age. The voltage might be already set to 120VAC, probably by the importer, to get the regulatory sticker, so they just did not bother with changing the rear panel sticker. 61V on the 80V capacitor is about right for the rails anyway, and that transformer certainly never has run warm in any way.
I once had a broken fuse that acted like a time delay. The fusible link had a hairline crack in it.
Nothing wrong with your fault-finding methods, Dave.
I can tell you’re from around my age. My “elders” used to give me s**t if I banged on something to troubleshoot or if I “Easter egged”. Even if it was cheaper. The NASA crowd and older, they always wanted to know the exact cause.
My elsers were the ones that taught me to rattle and smack everything. You should have see what the engineers did at the TV station I interned at. I am surprised the old CEI280 cameras even worked at all considering the abuse the engineers and crew gave them. Bad connections everywhere and they were generally fixed with a smack on one side or the other.
I started work in about 75 in the Houston area. Worked with a lot of Viet Nam era ex military technicians and lots of ex NASA technicians. Those guys were crazy strict. Also started working on geophysical electronics - cost a pretty penny. Not to say there weren’t a few properly timed percussive taps used every now and then.
Percussive maintenance is all well and good for troubleshooting, but I don't like to rely on it during use. I would like to know the cause of the fault as well, and then fix it, rather than making a habit of pounding on something until it works, and then hoping it continues to -- because it probably won't, and then I'll want to pound on it out of frustration.
FWIW, I definitely don't want to hear someone on a space shuttle telling me, "oh it does that -- just smack it until it starts working again." Naw, man! This isn't a shop radio! Fix it! hahah
@@nickwallette6201 Well tapping intermittent is how we find the fault. It allows localizing the fault. Once the area is found then move to the plastic spudger to lightoy scrape the board or probe individual connections to see if the fault reoccurs and then go in and fix the problem. With the cameras that were always faulting at the TV station they were beat up so much because the engineers never were able to fix the problem. They would work on them, and then in the next production, right in the middle of a shoot one of them would start acting up. We would stop tape, smack the camera a few times to get it working and then continue, and the engineer would be back on it again and not fix it.
@@12voltvids I'm with you all the way on finding faults, and I get sometimes you do what you have to do when you can't find an intermittent fault, and have to keep using something anyway.
What bugs me is people who put up with stuff that can be easily fixed, like a dodgy connector, or bad cable, or something like that. :-) Smacking is a temporary fix!
Mabey It Was A Triped Circuit Breaker.
Tapping on components to test for loose connections is a perfectly valid diagnostic method. Dragging chassis/faceplates/heatsinks around on your bench potentially causing scratches and worn edges makes me cringe.
I don't drag them around. I lift the edge with any edges that could get scratched. In this case the unit is already beat up. If i have a piece that is in immaculate condition I will either put a rag down under it or stick tape on the edge during service. Watch when i move things. I lift the front side up.
the msg to the snowflakes cracked me up
Snowflakes are enraged and unsubing in numbers.
I get annoying posters on my Turntable Guy channel all the time telling me what to do, what I've done wrong, etc, etc. It's best to ignore them, mute them, ban them. Putting a snowflake message on the video is just going to get people to turn the video off. The term snowflake brings with it a lot of baggage.
Can't handle the heat get out if the kitchen. The snowflakes know who they are. When they whine and complain so does everyone else.
120 watts per channel according to the specs
Sounds about right
Heartbroken how this amp is scrached all around
Hmmmmm, that's no good. 00:30 And yes, agreed, this is a tried and tested diagnostic method. 01:36
I have a CD player that is humming the same. UNICO. CD.
Nice amp..........
This one would certainly be welcome in my system.
It's Funny You'r Not Getting A Copywrite Stike On The Music You'r Playing Now.
The music i use is royalty free and I have the license to use it. Quite often the radio inside the house gets picked up by the microphone but it is so low in the background that it doesn't register and if it did I would just mask it with fan noise.
👍👍👌👍
@12voltvids 1:37 this testing methode is s improved work all over the world. In Germany call3d it "Kalte Lötstellen suchen" 👍👍