Hi Friends,
I just inherited this unit, whose previous (and original) owner was a cat and cigar lover. But the fact that the knobs and faceplate were literally bronzed with nicotine, and that it still smells strongly of smoke and cat urine after a thorough cleaning is the least of the problems at the moment. There seems to be no signal from one channel. I managed to determine that both sides of the power section worked by use of the MONO button, and so I'm pretty sure the problem lies in the preamp. However, after spraying out the switches and pots with De-Oxit, now the MONO button trick has no effect, though I'm still fairly sure the trouble is in the pre section.
My question: are there any "usual supsects" with this model that might help me zero in on the problem--say, electrolytic failures, etc? I do have the schematic, but I'm not too thrilled about the prospect of tracing out the whole dang thing unless I'm confident it can be a one-day sort of job. Otherwise I'm tempted to take it to a service center.
Any help much appreciated!
Regards,
Joe
I just inherited this unit, whose previous (and original) owner was a cat and cigar lover. But the fact that the knobs and faceplate were literally bronzed with nicotine, and that it still smells strongly of smoke and cat urine after a thorough cleaning is the least of the problems at the moment. There seems to be no signal from one channel. I managed to determine that both sides of the power section worked by use of the MONO button, and so I'm pretty sure the problem lies in the preamp. However, after spraying out the switches and pots with De-Oxit, now the MONO button trick has no effect, though I'm still fairly sure the trouble is in the pre section.
My question: are there any "usual supsects" with this model that might help me zero in on the problem--say, electrolytic failures, etc? I do have the schematic, but I'm not too thrilled about the prospect of tracing out the whole dang thing unless I'm confident it can be a one-day sort of job. Otherwise I'm tempted to take it to a service center.
Any help much appreciated!
Regards,
Joe
Joe,
welcome.
I doubt you will find a service centre that will want to tackle that job. Indications are not that good and making this beauty back to work is a time consuming task. Diy is the only way to go. What worries most is the cat urine. Look at the copper traces and component legs is they are oxidized. A few locals can be fixed but if it's all over the place, you'll have a though time. Bad solderings and worn out caps, crackling pots and faulty trim pots are the most common errors to look for.
If it weren't a receiver, I would apply the dishwasher method to clean it.
Good luck and keep us posted.
/Hugo
welcome.
I doubt you will find a service centre that will want to tackle that job. Indications are not that good and making this beauty back to work is a time consuming task. Diy is the only way to go. What worries most is the cat urine. Look at the copper traces and component legs is they are oxidized. A few locals can be fixed but if it's all over the place, you'll have a though time. Bad solderings and worn out caps, crackling pots and faulty trim pots are the most common errors to look for.
If it weren't a receiver, I would apply the dishwasher method to clean it.
Good luck and keep us posted.
/Hugo
Hey Hugo,
Thanks for your reply. I think you're right in general about finding someone to service this old thing, but I happen to be fortunate enough to live not too far from an authorized MacIntosh dealer who also carries and services Marantz. They would be my only choice if I were to go that way. I'll take your advice and give it a fine tooth combing over. Thanks again!
Regards,
Joe
Thanks for your reply. I think you're right in general about finding someone to service this old thing, but I happen to be fortunate enough to live not too far from an authorized MacIntosh dealer who also carries and services Marantz. They would be my only choice if I were to go that way. I'll take your advice and give it a fine tooth combing over. Thanks again!
Regards,
Joe
There is a lot to learn from these old solid states. In general, basic servicing is rewarding because of the openness of the design.
You don't need expensive soldering tools, no magnifying glasses etc...
I'd give it a go if I were you, of course I have no idea of your experience with electronics.
/Hugo
You don't need expensive soldering tools, no magnifying glasses etc...
I'd give it a go if I were you, of course I have no idea of your experience with electronics.
/Hugo
switches...
clean them, clean them again, maybe disassemble and clean (tricky but it can be done) - if one channel is out for all inputs always suspect the tape monitor switch - it does not get used by many people
But if there is feline urine in the set then all bets are off - when I was fixing sets this was one of the few things that I would say no to. It stinks, is very caustic and therefore is very hard to guarantee and I hated to fix something twice. Becomes a labor of love. If there is damage from liquids as soon as possible rinse well with clean water (tap is ok) in a bathtub or whatever, get the worst out (shake?? reminds of some huge amplifier that the manufacturer told you to shake to check for loose screws once reassembled - it was as much as most of us could do to lift it!) and dry thoroughly before turning on.
If the liquid has been there for some time all kinds of nasty things can happen, some are real obvious, but some are not I've seen components that look fine and the board around them looks fine but one lead is completely eaten away - hence as a pro it was best to stay away from these sets. DIY well thats different, I once for myself took every component off the PCB, cleaned and repaired the PCB, checked every component and reassembled - lots of work, but fun in its own way.
The other liquids that are bad are coke (the drink) and water dripped from plants (why would you put your stereo below a plant?!?).
Cats seem to like laying on the warm sets, sometimes you just have to deal with the fur and dander, but sometimes...
So I guess I'm saying try cleaning first, and second, and when it is thoroughly ckean and the switchs are clean and known to be working then, and only then look else where.
Good luck, Bill
clean them, clean them again, maybe disassemble and clean (tricky but it can be done) - if one channel is out for all inputs always suspect the tape monitor switch - it does not get used by many people
But if there is feline urine in the set then all bets are off - when I was fixing sets this was one of the few things that I would say no to. It stinks, is very caustic and therefore is very hard to guarantee and I hated to fix something twice. Becomes a labor of love. If there is damage from liquids as soon as possible rinse well with clean water (tap is ok) in a bathtub or whatever, get the worst out (shake?? reminds of some huge amplifier that the manufacturer told you to shake to check for loose screws once reassembled - it was as much as most of us could do to lift it!) and dry thoroughly before turning on.
If the liquid has been there for some time all kinds of nasty things can happen, some are real obvious, but some are not I've seen components that look fine and the board around them looks fine but one lead is completely eaten away - hence as a pro it was best to stay away from these sets. DIY well thats different, I once for myself took every component off the PCB, cleaned and repaired the PCB, checked every component and reassembled - lots of work, but fun in its own way.
The other liquids that are bad are coke (the drink) and water dripped from plants (why would you put your stereo below a plant?!?).
Cats seem to like laying on the warm sets, sometimes you just have to deal with the fur and dander, but sometimes...
So I guess I'm saying try cleaning first, and second, and when it is thoroughly ckean and the switchs are clean and known to be working then, and only then look else where.
Good luck, Bill
I'm got a 2245 that has lost audio as well, in both channels (though no cat pee or nicotine is involved in my case). For a while I would need to turn the volume up fairly high before I'd get anything to the speakers. Once the juice was flowing I could choose any volume level I wanted.
Now, there is no output at all. I turned the volume to max (cringing while I did so) but nothing happened. This is the same for all input sources.
Any suggestions as to where I should start? I did buy a service manual on eBay, which hasn't arrived yet.
Thanks
Now, there is no output at all. I turned the volume to max (cringing while I did so) but nothing happened. This is the same for all input sources.
Any suggestions as to where I should start? I did buy a service manual on eBay, which hasn't arrived yet.
Thanks
Bane2871 said:
This sounds like the same behaviour my 2285B showed when it had a bad relay power supply. Try tapping the top of the case to see if it suddenly switches the speakers on. If so, it's probably a bad capacitor in the little relay board - at least replacing those on my 2285B solved that particular problem.
For the original poster - if you have access to an oscilloscope it should be relatively straightforward to attach a source and follow through the circuit seeing where the signal gets to. Aside from signal-path caps, the relay, speaker switches, mono switches, tape monitor switches, source selector switch, tone control range switch (if any) and the pre-out / main-in jumpers, which may be internal, are all suspects. Remember the DeOxit has to get into the control, but you then need to work it a couple of dozen times and wait for it to dry.
Hi Bane2871,
Clean all the dust and debris out first and take some digital pictures before you do anything. Check the main filter caps for broken or leaking seals.
Get a service manual or schematic before going further. Refer to it often. Before you start, measure the DC offset and bias currents. This tells you some things. Close the tuning cap up so it doesn't get damaged as you work (plates meshed together).
Now, replace all the electrolytic caps in the low voltage power supplies, the amplifier boards and the tone board. Clean the controls and switches at this point in time. Make sure you do not get any cleaner into the tuning capacitor or any of the trimmers.
If you replace the dial lamps, make sure you do them all at once. You must use 8V 200mA "fuselamps". Most have higher current ratings that will ruin the reflector for the tuning dial.
Lastly, do not twiddle any controls or adjustments without a clear understanding of what you are doing. This is especially true of the RF stages. If you think you know, you don't. Yo must know what you are doing.
Not a bad set BTW. Nice find.
-Chris
Clean all the dust and debris out first and take some digital pictures before you do anything. Check the main filter caps for broken or leaking seals.
Get a service manual or schematic before going further. Refer to it often. Before you start, measure the DC offset and bias currents. This tells you some things. Close the tuning cap up so it doesn't get damaged as you work (plates meshed together).
Now, replace all the electrolytic caps in the low voltage power supplies, the amplifier boards and the tone board. Clean the controls and switches at this point in time. Make sure you do not get any cleaner into the tuning capacitor or any of the trimmers.
If you replace the dial lamps, make sure you do them all at once. You must use 8V 200mA "fuselamps". Most have higher current ratings that will ruin the reflector for the tuning dial.
Lastly, do not twiddle any controls or adjustments without a clear understanding of what you are doing. This is especially true of the RF stages. If you think you know, you don't. Yo must know what you are doing.
Not a bad set BTW. Nice find.
-Chris
OMG!!!!!!
I finally pulled the case apart on the Marantz. I have a Yamaha receiver that I've opened up and repaired. The Yamaha has nothing on the Marantz in terms of complexity of packaging. I can't get to anything without major dis-assembly. This is going to be a much more difficult and time consuming task than I thought. The real daunting part is that the bulk of the interior is dedicated to the tuner section, some of which needs to be removed to gain access to other parts, like the main filter caps. Its going to be several hours just to form a plan of attack. They sure don't build 'em like they used to.
Sorry, just needed to vent.
I finally pulled the case apart on the Marantz. I have a Yamaha receiver that I've opened up and repaired. The Yamaha has nothing on the Marantz in terms of complexity of packaging. I can't get to anything without major dis-assembly. This is going to be a much more difficult and time consuming task than I thought. The real daunting part is that the bulk of the interior is dedicated to the tuner section, some of which needs to be removed to gain access to other parts, like the main filter caps. Its going to be several hours just to form a plan of attack. They sure don't build 'em like they used to.
Sorry, just needed to vent.
Hi Bane2871,
How did you make out on the Marantz?
BTW, you do not have to remove any part of the tuner unless you need to work on one of the boards, which is rare.
To be honest with you, I've worked on many, many Marantz and Yamaha units. The only Marantz units I really don't like are the quad units. Those are packed tight. There are some truly horrendous units out there for accessing parts. That Marantz is not bad in comparison.
-Chris
How did you make out on the Marantz?
BTW, you do not have to remove any part of the tuner unless you need to work on one of the boards, which is rare.
To be honest with you, I've worked on many, many Marantz and Yamaha units. The only Marantz units I really don't like are the quad units. Those are packed tight. There are some truly horrendous units out there for accessing parts. That Marantz is not bad in comparison.
-Chris
The bulk of this thread is old, but in general, this symptom to me warrants looking at all the switches, tape monitor switches, input select switches, etc. Even EQ in/out switches. And of course signal can enter a volume or balance control without exiting its wiper. And don't forget on the rear of many is a switch to separate the pre amps and power amps for insert of a graphic or other accecssory. And even those bare metal jumpers that plug into RCA jacks for that purpose can get poor contact in the RCA.
Hi Enzo,
You forgot to mention the speaker relay.
Actually, a no signal problem sounds more like the +35 VDC supply is down. That would kill the tone amp and also some models used this +35 VDC supply to run the tail current for the diff pairs in the amps. So losing the supply would kill all audio. So would losing just the resistor that feeds the tone board, in case it has a 25 VDC filter capacitor and 35 V supply. Some were made like that.
Never clean switches without checking them first. Use cleaner sparingly. To check, slowly operate each switch and control. This way you can tell how bad it is (or isn't). Cleaner attacks lubricants, not good for bushings in controls or the carbon track. Besides, it is the metal contacts that are noisy, not the carbon track.
-Chris
You forgot to mention the speaker relay.
Actually, a no signal problem sounds more like the +35 VDC supply is down. That would kill the tone amp and also some models used this +35 VDC supply to run the tail current for the diff pairs in the amps. So losing the supply would kill all audio. So would losing just the resistor that feeds the tone board, in case it has a 25 VDC filter capacitor and 35 V supply. Some were made like that.
Never clean switches without checking them first. Use cleaner sparingly. To check, slowly operate each switch and control. This way you can tell how bad it is (or isn't). Cleaner attacks lubricants, not good for bushings in controls or the carbon track. Besides, it is the metal contacts that are noisy, not the carbon track.
-Chris
anatech said:
I Haven't actually done anything beyond opening the case and cleaning the insides a bit. After seeing that the time requirement was going to be substantially more than than originally though, it has been moved to the back burner for now (too many other demands on my time; family, work, etc.). I've re-read your post (and the other relevant posts) and am gearing up to take a stab at it now that I've gotten some other projects (mostly honey-do's) off my plate.
I looked at the interior again, and I'm not sure how I can replace many of the components without a lot of dis-assembly. The modules appear to be "nested" and solder points are hidden. Even the basic fixes mentioned above appear to require removal of modules.
That 22xx Marantz series are true classics Some of the best tuners ever made, I was able to get textbook perfect s-curves
out of them with a Sound Technology sig gen . the power amps were clean and open sounding.
Switches are going to be dirty and pots likley to be noisey, a shot of Cramolin should fix them up. You should replace the filter caps in any unit of that age. These are well worth the effort to restore
My favorite was the 2270 a true audio classic. Iam sure that you can find a manual around somewhere, I know the shop I used to work for has manuals for the whole line.
out of them with a Sound Technology sig gen . the power amps were clean and open sounding.
Switches are going to be dirty and pots likley to be noisey, a shot of Cramolin should fix them up. You should replace the filter caps in any unit of that age. These are well worth the effort to restore
My favorite was the 2270 a true audio classic. Iam sure that you can find a manual around somewhere, I know the shop I used to work for has manuals for the whole line.
Hi Bane2871,
Yes, the amp modules are soldered in on that one. It doesn't really take a lot of time to remove them, let me guide you a little....
1. Flip the chassis over so you are looking at the bottom of the chassis.
2. Take digital pictures of each bottom side so you can see the wire colors.
3. Take pictures of the ground connections. You will see what I mean.
4. Unsolder the ground straps and wire, or undo the screw if possible.
5. Unsolder the other wires leading to the amp PCBs.
6. Release the heat sinks from the chassis one at a time.
7. Put the screws in a container or small plastic bag, set them aside.
8. Work on one output assembly at a time, release the PCB from the heat sink.
9. Take digital pictures of each PCB from several angles. You have cap polarities now.
10. Take digital pictures of the power transistors, again you noted the locations.
11. Take your time and remove everything else from the heat sinks.
12. Store all the screws and label as above.
13. Clean all the heat sink surfaces and power transistors carefully.
14. Test these parts using a jig or transistor tester like a Heathkit IT-18.
15. Mark down the beta readings, mark if leaky C-E or C-B. Store.
16. I normally test all the capacitors as I remove and test them. Optional.
17. Match the differential pair. If not matched well, install matched replacements.
18. Do test the other transistors. Replace if defective (leaky or low beta).
19. Replace resistors that are over heated, if any.
20. Match emitter resistors of diff pair carefully (if they exist).
21. Replace capacitors with the same or improved types.
22. Recheck your soldering carefully, clean the flux off and check them again.
23. Install the output transistors, use new mica insulators (TO-3).
Make sure you use a thin coat of new thermal compound here!!
24. Reinstall the PCB onto the heat sink.
25. Optional. Test the amp using a power supply. I do this.
26. Do the other channel as you did this one.
Before you put the amps back in, service the power supply. You may have to remove the speaker wires from the amp side. Flip it up now after removing and storing the screws. Same general idea as the amp service.
The tone PCB is easy to release, remove the face plate and clean it. Remove the tone board and service that.
Put things back together in reverse order. Use a variac the first time you power it up. Stop at 20 VAC intervals to make sure nothing is drawing too much current. Check your power supply voltages from the regulator every 20 VAC after you reach 60 VAC input. Keep an eye on your primary current.
I do this in case there is a pinched wire or error in your work. I'd rather not see smoke.
The phono PCB flips out easily for service. If you see a pair of 2SC458, replace those with 2SC1775A. This is an ECO from Marantz as the 2SC458 tend to fail. The newer parts are more quiet.
If you replace any lamps, they must be 200 mA, never use 250 mA or even 300 mA!
Do not adjust or replace capacitors in the tuner, IF, MPX or AM circuits. Most receivers I see these days have been mis-adjusted. I just looked at a 2385 that is so far out, it's silly. The customer even paid for this!
-Chris
Yes, the amp modules are soldered in on that one. It doesn't really take a lot of time to remove them, let me guide you a little....
1. Flip the chassis over so you are looking at the bottom of the chassis.
2. Take digital pictures of each bottom side so you can see the wire colors.
3. Take pictures of the ground connections. You will see what I mean.
4. Unsolder the ground straps and wire, or undo the screw if possible.
5. Unsolder the other wires leading to the amp PCBs.
6. Release the heat sinks from the chassis one at a time.
7. Put the screws in a container or small plastic bag, set them aside.
8. Work on one output assembly at a time, release the PCB from the heat sink.
9. Take digital pictures of each PCB from several angles. You have cap polarities now.
10. Take digital pictures of the power transistors, again you noted the locations.
11. Take your time and remove everything else from the heat sinks.
12. Store all the screws and label as above.
13. Clean all the heat sink surfaces and power transistors carefully.
14. Test these parts using a jig or transistor tester like a Heathkit IT-18.
15. Mark down the beta readings, mark if leaky C-E or C-B. Store.
16. I normally test all the capacitors as I remove and test them. Optional.
17. Match the differential pair. If not matched well, install matched replacements.
18. Do test the other transistors. Replace if defective (leaky or low beta).
19. Replace resistors that are over heated, if any.
20. Match emitter resistors of diff pair carefully (if they exist).
21. Replace capacitors with the same or improved types.
22. Recheck your soldering carefully, clean the flux off and check them again.
23. Install the output transistors, use new mica insulators (TO-3).
Make sure you use a thin coat of new thermal compound here!!
24. Reinstall the PCB onto the heat sink.
25. Optional. Test the amp using a power supply. I do this.
26. Do the other channel as you did this one.
Before you put the amps back in, service the power supply. You may have to remove the speaker wires from the amp side. Flip it up now after removing and storing the screws. Same general idea as the amp service.
The tone PCB is easy to release, remove the face plate and clean it. Remove the tone board and service that.
Put things back together in reverse order. Use a variac the first time you power it up. Stop at 20 VAC intervals to make sure nothing is drawing too much current. Check your power supply voltages from the regulator every 20 VAC after you reach 60 VAC input. Keep an eye on your primary current.
I do this in case there is a pinched wire or error in your work. I'd rather not see smoke.
The phono PCB flips out easily for service. If you see a pair of 2SC458, replace those with 2SC1775A. This is an ECO from Marantz as the 2SC458 tend to fail. The newer parts are more quiet.
If you replace any lamps, they must be 200 mA, never use 250 mA or even 300 mA!
Do not adjust or replace capacitors in the tuner, IF, MPX or AM circuits. Most receivers I see these days have been mis-adjusted. I just looked at a 2385 that is so far out, it's silly. The customer even paid for this!
-Chris
BY ANATECH :
Do not adjust or replace capacitors in the tuner, IF, MPX or AM circuits. Most receivers I see these days have been mis-adjusted. I just looked at a 2385 that is so far out, it's silly. The customer even paid for this!
chris i will have to have a diferent opinion on this and actually this comes from very close expirience
i usually take a look at tuners also since i have the ability to reset them again ....in the particular unit in the left tuner area as we look at it from the front there is a large ammount of caps and most of them are psu related ....just a few days ago a similar unit come in cause there was a constand 1.5 khz sound in the all unit
faulty caps in the tuner area cused oscilation and tha all unit was doomed
i will sugest recap everything anyway but be very very carefull with other tuning settings ( if the tuner is faulty replacing the caps all arround will only do good .)
i heard you had some health problems ...I wish you all the best and a fast recovery ....
thanks for your time chris
Do not adjust or replace capacitors in the tuner, IF, MPX or AM circuits. Most receivers I see these days have been mis-adjusted. I just looked at a 2385 that is so far out, it's silly. The customer even paid for this!
chris i will have to have a diferent opinion on this and actually this comes from very close expirience
i usually take a look at tuners also since i have the ability to reset them again ....in the particular unit in the left tuner area as we look at it from the front there is a large ammount of caps and most of them are psu related ....just a few days ago a similar unit come in cause there was a constand 1.5 khz sound in the all unit
faulty caps in the tuner area cused oscilation and tha all unit was doomed
i will sugest recap everything anyway but be very very carefull with other tuning settings ( if the tuner is faulty replacing the caps all arround will only do good .)
i heard you had some health problems ...I wish you all the best and a fast recovery ....
thanks for your time chris
Hi Sakis,
Thank you kindly for wishing me well. There is really no great recovery possible, but maybe a reduction in pain sometime.
I understand what you are saying, and in your case I completely agree with you.
However.
Most technicians don't really understand how to set up a tuner, and those who do, most will not take the time to go back and forth in adjustments as most manuals suggest. The newer tuners are mostly adjustment free. That doesn't mean the alignment is right though. All it means is that component value changes are required to get it right. Then there are those that are simply bad.
When you don't understand what you are doing completely, the job may look easier than it really is to do properly.
My fear are those "modders" out there that might change capacitor values in areas where the type is critical. Some caps are temperature compensating components and others must be what is already there. There are tuned circuits in these areas that may not be adjustable in the normal sense. People have to respect that RF circuits are different from audio only circuits.
Many adjustments are interactive as well. Lovely if someone is a control twiddler.
I've seen a number of bad components as well in tuners. But no way am I going to replace anything unless the part is bad. Supply bypass caps and charge pump caps are another story, but how does someone who is not a tech identify these critters?
In short, a tweaker is very likely to cause more trouble if they play in these areas. The same holds true with the servo and RF sections of CD and DVD players. Seen a couple written off so far. These areas really should be left to someone who is very familiar with these circuits. Of course, their work should be very good too.
Sorry to disagree with you, but I think we actually think the same. Electrolytic caps are one thing. I'm worried about coil position / spacing and those ceramic capacitors. You may only be talking about the normal electrolytic caps.
One final point about working in tuner sections. It's far too easy to burn through the dial cord. You do not want to damage the dial cord in any way!!! I hate restringing tuners, I;m not very good at it.
-Chris
Thank you kindly for wishing me well. There is really no great recovery possible, but maybe a reduction in pain sometime.
I understand what you are saying, and in your case I completely agree with you.
However.
Most technicians don't really understand how to set up a tuner, and those who do, most will not take the time to go back and forth in adjustments as most manuals suggest. The newer tuners are mostly adjustment free. That doesn't mean the alignment is right though. All it means is that component value changes are required to get it right. Then there are those that are simply bad.
When you don't understand what you are doing completely, the job may look easier than it really is to do properly.
My fear are those "modders" out there that might change capacitor values in areas where the type is critical. Some caps are temperature compensating components and others must be what is already there. There are tuned circuits in these areas that may not be adjustable in the normal sense. People have to respect that RF circuits are different from audio only circuits.
Many adjustments are interactive as well. Lovely if someone is a control twiddler.
I've seen a number of bad components as well in tuners. But no way am I going to replace anything unless the part is bad. Supply bypass caps and charge pump caps are another story, but how does someone who is not a tech identify these critters?
In short, a tweaker is very likely to cause more trouble if they play in these areas. The same holds true with the servo and RF sections of CD and DVD players. Seen a couple written off so far. These areas really should be left to someone who is very familiar with these circuits. Of course, their work should be very good too.
Sorry to disagree with you, but I think we actually think the same. Electrolytic caps are one thing. I'm worried about coil position / spacing and those ceramic capacitors. You may only be talking about the normal electrolytic caps.
One final point about working in tuner sections. It's far too easy to burn through the dial cord. You do not want to damage the dial cord in any way!!! I hate restringing tuners, I;m not very good at it.
-Chris
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