This job is amazing. Really nice and professionally done. I don't think that the best dentist doing root canal is more patient than you are during the troubleshooting and repairs.
I had to replace a relay on my Marantz Model 250 power amp a few months ago. The problem was that no replacement existed. The original Factory relay was an oddball in that the coil contacts were in the position occupied by the actuator contacts. Lucky for me I found a solution on a trouble site. They recommended a relay that wasn't an exact footprint as well as the coil and actuator contacts did not match, but otherwise the relay was a good match. First I had to open the relay and physically swap the wiring of the coil and the contact-er. Then I had to "muscle" the relay into the mismatched footprint. It was worth it. The unit works flawlessly now. I bought an extra relay because I have another Model 250 in another room.
Tony this video has been your best. I would expect this sort of thing with a very complicated equipment. The best part of this video is how you do the process of debugging the problem. This is something that is not taught in school. You have more experience than most in this area cause you work on very very expensive X Ray machines that cost 1000 more money than this receiver. You have been working on these X Ray machines for a long time and developed a methodology on working through the problem is what I find is the most on these videos.
Nice troubleshooting, thanks for the video :) It looks like you're getting a visit from our Canadian winter weather, it was really cold on Thursday and Friday.
I noticed the old fan you removed was made by Rotron fan company up in or near Saugerties, N.Y. that location is only about 3/4 hour drive North Northeast from where I live !! Interesting video on this big old beast receiver/amplifier!!
The active ingredient in Deoxit is cramolyn. I think Caig labs developed it themselves. My service dept. began using it in the early 1980s and had to thin it ourselves. I forgot whethrr we used alcohol or freon Tp-35 to do it. Works great!
Well you impressed me with all this hard work. Sometimes schematics and directions make us stupid with the relay as an example. I would be looking at the relay, looking at the traces and say, it must go this way. I rarely use diagrams but rarely go farther than just make it work and a few adjustments.
In regards to the relay w/ wrong pins... I once installed an LM317 voltage regulator with the pins of an LM780x -- I had completely forgotten that there were different and it took me a while to figure out why it was not working. It is good that these regulators have some internal protection and there was no magic smoke...
The first mention of a computer bug was when they foud an actual bug dead between some relay switches back in 1947.
5 років тому
Surprised to see how many areas that required repair on this unit, seems unusual. Generally receivers are quite reliable but this one has had more than it's share of problems. In your opinion do you suspect design, component selection or is this typical of these huge receivers. This makes a good argument for separates.
This was a great series, thank you a bunch Tony, great insight here. Have to tell you how great your filter cap upgrade looks too, it is such a nice job! You really do wonderful work, thanks a lot for taking all the time to record and post your videos, they are all greatly appreciated. I’m curious, have you ever worked on a Harmon Kardon 730 before? I found one yesterday and was able to talk the fella down to $25 on it. His kid took a gold paint bomb to it and painted the outer case and did an absolutely crap job. (It’s so horrible looking right now) I glanced at the guys and it doesn’t look like anyone has been in it. I also pulled the service and operations manual off the Internet but was wondering if this is worth a complete resto like you performed on this receiver. It’s only 40 watts per channel but it has a lot of followers online. Thanks, Buddy
I wonder why they used a power resistor to lower voltage to the fan? I've often used a capacitor in series with the fan and a thermal switch that shorts out the capacitor when hot to allow the fan to run a full voltage in this state.
I got lucky last year on ebay. I found a seller who had over 100 cans of vintage Cemtronics tuner cleaner, the "real" stuff. Trichlorofluoromethane and trichlorotrifluoroethane mixture. Had been very sparingly using my last can for close to 2 years. When i saw those on ebay I bought every can he had. Something I keep forgetting to ask. Why do you conformally coat the boards? I know it can't be for moisture protection because you only do the solder side of the board. Only time I conformally coat boards is if I'm doing something that's going to be mounted outdoors and in that application I coat the entire board (top and bottom) with about a 1/8 inch thick layer of UV cure coating.
HI Mike! I only touch up the boards that already have coating on them.. A lot of the gear from this era had a coating on the back of the boards. It's not really the same as the stuff they used on military or high quality test gear, as it will break down with alcohol and get hazy. I only use it for cosmetic purposes and I just use the MG chemicals stuff. Looks like watered down clear nail polish and makes the back of the board look "shiny and new". ;)
@@xraytonyb That's not a coating, that's left over flux residue from the wave soldering process. Common in most consumer electronics of the era. The 1980's vintage CB radio I'm currently working on that has a Uniden chassis in it is covered in it to. Since it's a "no clean flux" the manufacturers didn't bother cleaning the residue off after wave soldering the boards.
Its quite funny... to connect the heating up resistor and cooling down fan in series. :) Maybe it would be better to omit the resistor at all and install a fan with built in (even custom) pwm speed control based on some thermal sensor?
I just saw one of the ridiculous Super Bowl Ads on TV. A guy shows up at a yard sale and there is a Marantz receiver for sale. Fat chance of that happening.
You can find Marantz receivers for sale everywhere around here... (Central Florida) The problem is they are all the cheap ones, certainly not a 2500 like this!
@@budandbean1 Years ago I saw one of these at a garage sale for 100.00 but it needed work and this was before the internet got really big and I didn't realize these were worth so much, I seen these go for 7,000 dollars or more on E bay. I kick myself every time I see one of these on here lol
Good point. I feel sometimes tempted to change the factory design of my own vintage sound equipment when I restore them (recap, cleaning, deoxi, etc.) -- not as complicated as this one, I can't do a project like this. But I would feel tempted to change the design of this fan altogether, however then one may not like to lose the originality of the project. On another point... I almost always replace all of the power supply's main transistors, power diodes, heatsinks, protection relays, etc. (I got a lot of knowledge about it watching his videos). But I try not to change transistors in the audio path in order to keep the original sound of the equipment.
@@kylesmithiii6150 I never worked much on consumer equipment once I got older. I never found people would pay for such an extensive restoration. I would fix the problem and anything obvious that is gone or failing. More like a Shango 66 fix
@Mark Anderson I can't agree more. I think that an average customer would want a "vanilla ice cream" type of repair. Only true collectors would be willing to pay $1000s in parts and labor for a repair like this. What I do is for my own humble collection -- I try to buy the best parts I can, usually from mouser. I feel satisfied with the final work (I try to do a clean work like this also using Q-tips, alcohol, etc.) -- usually worth the time and investment. For me the repair of this Marantz is worth more than a $1000 -- compare w/ the price of a new Yamaha A-S1100 ($2500). BTW, I was thinking of buying a reel-to-reel for restoration for my own use, but it is too much for me, I am not up to the challenge. I gave up. I use more nice vintage turntables, cassette decks, etc. My amplifiers from the late 70s/early 80s sound fantastic too (but they are for low power - I don't need more).
@@kylesmithiii6150 yes I had a Chinese friend who's dad had high end equipment in the 70s. He had upgraded to all Mac components and I remember this cool tandberg 64x open reel recorder. I loved that. He had tannoy speakers and later Mac speakers which were more like furniture. Was fun playing and using it. I also had a friend with b& w 801s i really liked them
carefull with the chinese aluminium resistors...i had them come open from the factory and i have read somewhere that the wattage rating they have marked refers to them being attached to a heatsink, i dont know however if that is true
I used high quality Dale resistors purchased from Mouser for the soft start and fan. They are rated for up to 600 volts. I do agree that some of the inexpensive Chinese resistors are pretty dodgy. Thanks for watching!
Bugs are one other thing to watch out for when purchasing used gear, anything you get these days can be infested with bed bugs and cock roaches and if they get out into your house, you'll have an expensive mess on your hands.
Meticulous as always. I'm just wondering whether the old fan couldn't be rebuilt with new ball bearings - apparently these things are standardized, and there isn't really an awful lot else to go bad in an AC motor. Probably not worth it given the advances in fan aerodynamics in the last 40 years, mind you, and your new fan looks solid enough, but maybe someone would like the keep things as original as possible. I also have to imagine that a solid 120mm fan like that isn't too cheap, unlike some ball bearings.
As a nooby, I would rather see you do the actual work for a learning experience. Seeing you talk about what you're going to do and the next shot it's finished and reassembled is no help to me.
I know I am a hand guy I should know my metrics but I don't know my metrics in this is the USA dude I don't know why you don't use inches that would be super cool if you could
Well Adron, the USA is the only country in the world still using feet and inches, and Fahrenheit for that matter. It might take another 20 years to catch up with everyone else in the world but you are going to do it one day!! Now is a good time to start. A double sided ruler might be a good start. Well done Tony!
I use mm or cm in projects almost all the time. I use inches if I have to. For those who are not used to mm and cm way of measuring, you may be missing how useful, precise and practical it is.
@@kylesmithiii6150 I agree Kyle, I was brought up in feet and inches but like everything if you use these measurements you soon learn, or you can always ignore the rest of the world and bury your head in the sand, we all have a choice!
That's the first time I've ever seen a wire-unwrapper. Awesome!
I am always amazed by the superb knowledge, patience, problem solving capability of Tony. Way to go!
This job is amazing. Really nice and professionally done. I don't think that the best dentist doing root canal is more patient than you are during the troubleshooting and repairs.
I had to replace a relay on my Marantz Model 250 power amp a few months ago. The problem was that no replacement existed. The original Factory relay was an oddball in that the coil contacts were in the position occupied by the actuator contacts. Lucky for me I found a solution on a trouble site. They recommended a relay that wasn't an exact footprint as well as the coil and actuator contacts did not match, but otherwise the relay was a good match. First I had to open the relay and physically swap the wiring of the coil and the contact-er. Then I had to "muscle" the relay into the mismatched footprint.
It was worth it. The unit works flawlessly now. I bought an extra relay because I have another Model 250 in another room.
Wow what a project,prob not a better man around to execute this restoration process,thanks for sharing,really enjoying this one!
Tony this video has been your best. I would expect this sort of thing with a very complicated equipment. The best part of this video is how you do the process of debugging the problem. This is something that is not taught in school. You have more experience than most in this area cause you work on very very expensive X Ray machines that cost 1000 more money than this receiver. You have been working on these X Ray machines for a long time and developed a methodology on working through the problem is what I find is the most on these videos.
"Awkward as an Ostrich in a porta-potty here." Now, there's an image! Great video Tony; as always!
Wow, when this video started I was like 😲, good job you really know how to put these back together! Another great series and superb amp.
Nice troubleshooting, thanks for the video :) It looks like you're getting a visit from our Canadian winter weather, it was really cold on Thursday and Friday.
Definately doing serious effort in cleaning and renew this reciever im shure its gonna be a keeper and a display point in your collection .
Great work with this lovely old beast. Everyone's allowed the woopsie moments 👍
I noticed the old fan you removed was made by Rotron fan company up in or near Saugerties, N.Y. that location is only about 3/4 hour drive North Northeast from where I live !! Interesting video on this big old beast receiver/amplifier!!
thank u so much for those marantz 2500 videos do u have any videos of the scope repair or servise Thanks Mark
Hi Tony. Great job. I am sure you will never put a relay in backwards again. Always double check. Some brands have different connections.
Good stuff Tony! Talk about a mess in the beginning.
they put that relay in backwards. what a repair shop.
Very nice, Tony! Thanks!
The active ingredient in Deoxit is cramolyn. I think Caig labs developed it themselves. My service dept. began using it in the early 1980s and had to thin it ourselves. I forgot whethrr we used alcohol or freon Tp-35 to do it. Works great!
Great as always Tony, but I am amazed you did not have to turn the camera off to turn the air blue for a few seconds, I know I would've had to! :o)
Well you impressed me with all this hard work. Sometimes schematics and directions make us stupid with the relay as an example. I would be looking at the relay, looking at the traces and say, it must go this way. I rarely use diagrams but rarely go farther than just make it work and a few adjustments.
In regards to the relay w/ wrong pins... I once installed an LM317 voltage regulator with the pins of an LM780x -- I had completely forgotten that there were different and it took me a while to figure out why it was not working. It is good that these regulators have some internal protection and there was no magic smoke...
The first mention of a computer bug was when they foud an actual bug dead between some relay switches back in 1947.
Surprised to see how many areas that required repair on this unit, seems unusual. Generally receivers are quite reliable but this one has had more than it's share of problems. In your opinion do you suspect design, component selection or is this typical of these huge receivers. This makes a good argument for separates.
This was a great series, thank you a bunch Tony, great insight here. Have to tell you how great your filter cap upgrade looks too, it is such a nice job! You really do wonderful work, thanks a lot for taking all the time to record and post your videos, they are all greatly appreciated.
I’m curious, have you ever worked on a Harmon Kardon 730 before? I found one yesterday and was able to talk the fella down to $25 on it. His kid took a gold paint bomb to it and painted the outer case and did an absolutely crap job. (It’s so horrible looking right now) I glanced at the guys and it doesn’t look like anyone has been in it. I also pulled the service and operations manual off the Internet but was wondering if this is worth a complete resto like you performed on this receiver. It’s only 40 watts per channel but it has a lot of followers online. Thanks, Buddy
Time for some late night amp repair!
I wonder why they used a power resistor to lower voltage to the fan? I've often used a capacitor in series with the fan and a thermal switch that shorts out the capacitor when hot to allow the fan to run a full voltage in this state.
Tony.. can I ask how many man hours this restoration took.. best wishes.. T
Most contacts are silver plated, if scratched by sanding destroys the polished surface causing them not to last very long.
Hi, Can you please explain the CRT circuit and how it works? Thank you
I got lucky last year on ebay. I found a seller who had over 100 cans of vintage Cemtronics tuner cleaner, the "real" stuff. Trichlorofluoromethane and trichlorotrifluoroethane mixture. Had been very sparingly using my last can for close to 2 years. When i saw those on ebay I bought every can he had.
Something I keep forgetting to ask. Why do you conformally coat the boards? I know it can't be for moisture protection because you only do the solder side of the board. Only time I conformally coat boards is if I'm doing something that's going to be mounted outdoors and in that application I coat the entire board (top and bottom) with about a 1/8 inch thick layer of UV cure coating.
HI Mike! I only touch up the boards that already have coating on them.. A lot of the gear from this era had a coating on the back of the boards. It's not really the same as the stuff they used on military or high quality test gear, as it will break down with alcohol and get hazy. I only use it for cosmetic purposes and I just use the MG chemicals stuff. Looks like watered down clear nail polish and makes the back of the board look "shiny and new". ;)
@@xraytonyb
That's not a coating, that's left over flux residue from the wave soldering process. Common in most consumer electronics of the era. The 1980's vintage CB radio I'm currently working on that has a Uniden chassis in it is covered in it to. Since it's a "no clean flux" the manufacturers didn't bother cleaning the residue off after wave soldering the boards.
Its quite funny... to connect the heating up resistor and cooling down fan in series. :)
Maybe it would be better to omit the resistor at all and install a fan with built in (even custom) pwm speed control based on some thermal sensor?
27:30 - I'd err on the side of caution and clean the tuning cap with compressed air!
41:30 - Couldn't you diagnose this my removing the dim-bulb and using your Variac and monitor the current while slowly bringing up the voltage?
Hey, Tony. I found that bug amusing. I'm curious. Is that why the phrase, " there was bug in the system" created?
Indeed
I just saw one of the ridiculous Super Bowl Ads on TV. A guy shows up at a yard sale and there is a Marantz receiver for sale. Fat chance of that happening.
You can find Marantz receivers for sale everywhere around here... (Central Florida) The problem is they are all the cheap ones, certainly not a 2500 like this!
I noticed that also.
@@budandbean1 Years ago I saw one of these at a garage sale for 100.00 but it needed work and this was before the internet got really big and I didn't realize these were worth so much, I seen these go for 7,000 dollars or more on E bay. I kick myself every time I see one of these on here lol
I found one in a thrift shop in the 1990’s for $100
The first bug looks like a woodlouse :-)
Debugging the hardware :-)
Did you accidentally put in a dead transistor if so then replace it with a known good transistor.
How is an ostrich in a port a potty ackward????.......LOL
The RPM-Regulation of this fans is made with changing the frequency, never with pre-resistors.
I used to see resistors used to sense cooling in front of a fan. Not sure if it was resistor and thermistor together.
Good point. I feel sometimes tempted to change the factory design of my own vintage sound equipment when I restore them (recap, cleaning, deoxi, etc.) -- not as complicated as this one, I can't do a project like this. But I would feel tempted to change the design of this fan altogether, however then one may not like to lose the originality of the project. On another point... I almost always replace all of the power supply's main transistors, power diodes, heatsinks, protection relays, etc. (I got a lot of knowledge about it watching his videos). But I try not to change transistors in the audio path in order to keep the original sound of the equipment.
@@kylesmithiii6150 I never worked much on consumer equipment once I got older. I never found people would pay for such an extensive restoration. I would fix the problem and anything obvious that is gone or failing. More like a Shango 66 fix
@Mark Anderson
I can't agree more. I think that an average customer would want a "vanilla ice cream" type of repair. Only true collectors would be willing to pay $1000s in parts and labor for a repair like this. What I do is for my own humble collection -- I try to buy the best parts I can, usually from mouser. I feel satisfied with the final work (I try to do a clean work like this also using Q-tips, alcohol, etc.) -- usually worth the time and investment. For me the repair of this Marantz is worth more than a $1000 -- compare w/ the price of a new Yamaha A-S1100 ($2500). BTW, I was thinking of buying a reel-to-reel for restoration for my own use, but it is too much for me, I am not up to the challenge. I gave up. I use more nice vintage turntables, cassette decks, etc. My amplifiers from the late 70s/early 80s sound fantastic too (but they are for low power - I don't need more).
@@kylesmithiii6150 yes I had a Chinese friend who's dad had high end equipment in the 70s. He had upgraded to all Mac components and I remember this cool tandberg 64x open reel recorder. I loved that. He had tannoy speakers and later Mac speakers which were more like furniture. Was fun playing and using it. I also had a friend with b& w 801s i really liked them
carefull with the chinese aluminium resistors...i had them come open from the factory and i have read somewhere that the wattage rating they have marked refers to them being attached to a heatsink, i dont know however if that is true
I used high quality Dale resistors purchased from Mouser for the soft start and fan. They are rated for up to 600 volts. I do agree that some of the inexpensive Chinese resistors are pretty dodgy. Thanks for watching!
@@xraytonyb yep i saw it but be carefull with knock-off's... anyway nice job on the amp!
can you fix mine?
Bugs are one other thing to watch out for when purchasing used gear, anything you get these days can be infested with bed bugs and cock roaches and if they get out into your house, you'll have an expensive mess on your hands.
16:15 looks like the engineer died!
Mara(m)tz? :-)
Meticulous as always. I'm just wondering whether the old fan couldn't be rebuilt with new ball bearings - apparently these things are standardized, and there isn't really an awful lot else to go bad in an AC motor. Probably not worth it given the advances in fan aerodynamics in the last 40 years, mind you, and your new fan looks solid enough, but maybe someone would like the keep things as original as possible. I also have to imagine that a solid 120mm fan like that isn't too cheap, unlike some ball bearings.
Barium would have poop in it!
wish you had a like button
He does I just pressed it
@@jonka1 But I don't see the like and dislike bar : (
That's strange. On my screen it's there right below the video window as always. Tony shows the words without the numbers.
@@jonka1 ok
This is excellent but the constant clearing of the throat is incredibly annoying.
As a nooby, I would rather see you do the actual work for a learning experience. Seeing you talk about what you're going to do and the next shot it's finished and reassembled is no help to me.
I know I am a hand guy I should know my metrics but I don't know my metrics in this is the USA dude I don't know why you don't use inches that would be super cool if you could
Well Adron, the USA is the only country in the world still using feet and inches, and Fahrenheit for that matter. It might take another 20 years to catch up with everyone else in the world but you are going to do it one day!! Now is a good time to start. A double sided ruler might be a good start. Well done Tony!
I actually used a double sided ruler when I measured the fan in the video!
I use mm or cm in projects almost all the time. I use inches if I have to. For those who are not used to mm and cm way of measuring, you may be missing how useful, precise and practical it is.
@@kylesmithiii6150 I agree Kyle, I was brought up in feet and inches but like everything if you use these measurements you soon learn, or you can always ignore the rest of the world and bury your head in the sand, we all have a choice!