Marantz 2245 has no sound

The L and R channel amp boards are the same. The L amp is rotated half a turn so that the adjustment pots are to the bottom side whereas they are on top side for the R channel. The service manual call them the P750 board.

Did the Tech say what is wrong with the L channel board? If the board is not damage, repairing it would be the way to go. The output transistors are mounted on the heat sinks. You can buy replacements for those. The transistors, capacitors and resistors on the board are replaceable. Did he check the output transistors?

The early 2270 use the same design running at 47 vdc vs. 37 vdc for the 2245. Some of the components are different values like resistors. I think you need to stay with a 2245 board if you buy a used board. Others may know for sure about alternates.
 
The L and R channel amp boards are the same. The L amp is rotated half a turn so that the adjustment pots are to the bottom side whereas they are on top side for the R channel. The service manual call them the P750 board.

Did the Tech say what is wrong with the L channel board? If the board is not damage, repairing it would be the way to go. The output transistors are mounted on the heat sinks. You can buy replacements for those. The transistors, capacitors and resistors on the board are replaceable. Did he check the output transistors?

The early 2270 use the same design running at 47 vdc vs. 37 vdc for the 2245. Some of the components are different values like resistors. I think you need to stay with a 2245 board if you buy a used board. Others may know for sure about alternates.
First off , thanks for your Positive response, I feel a bit more reassured that it can be brought back to life.
The Tech didn't really go into detail , he only said he measured the voltage and it was some number that wasn't right ( sorry my memory sucks) . He didn't say the board was damaged only that the problem was the Left side and he wasn't sure which parts on the board were bad and he wasn't sure if the parts could even be had. He figured if he could get the parts it would be about $300 for his labour by the time he located and replaced what had to be replaced. I'm not sure if he checked the output resistors, he only said the Right side amp board had been worked on including the output transistors on the heatsink. He did say he checked the numbers on the replaced Right side Transistors and he said they weren't the ones that were suppose to be on there but at the same time being what he thought should have been a different transistor didn't nececarily mean they shouldn't work.
I did drop ot off to another guy that has done satelite reciever work for me, someone more likely to put time into locating the bad parts.
So would it be safe to say if the bare bones board was not damaged ( cracked ) then all the parts on the board could be had? Where from?
Thanks
Lynn
 
Once the tech figures out what parts are needed post the part ID number (the four digit number like C807 or H003 will do) from the manual on AK someone has likely found an acceptable substitute if that part is no longer made. For example, those right side output transistors are a substitute part since the original part is no longer available. I'm not aware of any components of the 2245 that an acceptable substitute is not available. Most newer electronic use integrated circuit chips that are not available once a device is over 10 years old or so. The part cost will not be much. The expense is in Technician labor.
 
Quick Update: Just spoke to tech on phone and of course he said he couldn't get the output transistors and said something mounting them over some sort of special paper. He wanted me to come down to see him, I told him basicly what ever parts needed to be had can be had but I need a list of the numbers and so he is making a list and I'll drop in to see him and see if he can put things in Laymans terms so I can explain them here and get lined up from you guys.
Curious Question, is there a specific type of paper or something that the output transistors were mounted on back in the 80's ? He said we would have to figure out a new location for mounting or something.
 
Not sure what he's talking about if it's actually the outputs he is discussing. They are mounted on the heat sinks with mica insulators under them the same way pretty much all audio output transistors are mounted. And replacements for the outputs are readily available, and I would think any qualified tech would know that. :dunno:
 
Not sure what he's talking about if it's actually the outputs he is discussing. They are mounted on the heat sinks with mica insulators under them the same way pretty much all audio output transistors are mounted. And replacements for the outputs are readily available, and I would think any qualified tech would know that. :dunno:
Perhaps the mica insulator is what he was talking about, keep in mind I don't know what I'm talking about. As for tech's in town here not knowing where to find 40 yr old replacement parts I would imagine they may or may not have the connections like you guys here on this Great Forum.
I've been researching on this site and its amazing what I'm finding/learning.
Was wondering though how do you test transistors when they are soldered into a board if there connected into a circuit board? This is really getting exciting.:jump:
 
He should be able to reuse the mica backing if he is carefully with it. The output transistors just slide in and out. No soldering required. The replacements are sold by Mouser. He will surely know them. The pnp transistor is a MJ21193G and the npn one is a MJ21194G. They are $5.50 each X2 plus shipping.

Did he take the old output transistor out and test them. It is very easy to get them reversed which will ruin the new ones. The tech must use the 2245 schematic to get them right. The tech also must use a non-conductive heat transfer paste.

The following link is a good one for the tech to read.

http://audiokarma.org/forums/index.php?threads/marantz-2245-subs-for-output-transistors.686452/
 
Perhaps the mica insulator is what he was talking about, keep in mind I don't know what I'm talking about. As for tech's in town here not knowing where to find 40 yr old replacement parts I would imagine they may or may not have the connections like you guys here on this Great Forum.
I've been researching on this site and its amazing what I'm finding/learning.
Was wondering though how do you test transistors when they are soldered into a board if there connected into a circuit board? This is really getting exciting.:jump:
On a 2245, the output transistors plug in. Remove two screws on each one and it will slide out to be tested and/or replaced. It's best to test transistors out of circuit. Here is a thread by the esteemed Echowars that is a tutorial on transistor testing.

http://audiokarma.org/forums/index.php?threads/bipolar-junction-transistor-testing-basics.43186/
 
Thanks guys for the helpful links.
So I stop by to see the tech and the guy I was speaking which had his dad elbows deep into it. They didn't find any problems with the Left side which the original guy said there was a problem. They had most of the right side removed and said the transistor outputs were ok. I was quite confused when they said Left side was good. They had already removed and replaced a bunch of capacitors which they said didn't fix anything. They said they are suspecting the relay. I sent them the pdf documentions for the 2245 as they had nothing to follow. :(

Pretty sure the red arrow points to the board the old guy replaced caps on
 
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That's the regulated power supply. It's always a good place to start. The relay is on that board, but otherwise, it's usually not a prime suspect if only one channel is bad.
 
Thanks Steven Tate any info helps at this point. I really wish I had known what I know now.
I came across this thread with the same symptoms and a great recommendation by RBuckner , Sounds like it's most likely C807, a 220uF/10V cap. You can use one rated at 16 or 25volts as they're more common. It could also be transistors getting low in gain or leaky too, H808-810.
http://audiokarma.org/forums/index.php?threads/marantz-2245-no-click-no-audio.602660/

Going to pass this info on to the Tech.
Thanks
Lynn
 
The power supply caps work hard and are definitely candidates for replacement. I'm fairly new to this myself, but I don't think any bad caps on that board would affect only one channel. But like I said, recapping the board and replacing the relay are first steps in any refurbish project to ensure nice clean, properly adjusted power to the rest of the unit. Others will chime in to verify if I'm wrong. :thumbsup:
 
You originally said there was no relay click, right? This does not sound like an issue with the relay its self.

The only issue that is common with a relay is dirty contacts. It clicks in but cuts out or takes some volume before the sound cuts in.
 
You originally said there was no relay click, right? This does not sound like an issue with the relay its self.

The only issue that is common with a relay is dirty contacts. It clicks in but cuts out or takes some volume before the sound cuts in.
Yes , there is no click but even with more volume did not give sound.
 
Yes , there is no click but even with more volume did not give sound.
Not sure why they would suspect the relay then. The only reason the relay its self would be responsible for it not clicking would be physical damage. Not likely if no one messed with between it working and not working. And easy to rule out by putting an ohm meter across the coil. Likely reasons for no relay click are a bad power supply voltage, issue with power amp, or issue with protection circuit.
 
Not sure why they would suspect the relay then. The only reason the relay its self would be responsible for it not clicking would be physical damage. Not likely if no one messed with between it working and not working. And easy to rule out by putting an ohm meter across the coil. Likely reasons for no relay click are a bad power supply voltage, issue with power amp, or issue with protection circuit.
I agree that Relay is probably good. I'm hoping with the Marantz service and parts manual pdf's I emailed them they can narrow down the issue. If the left side output amp is warm and right side output amp is cold while powered up ( as the tech said ) would that indicate anything definative?
 
I agree that Relay is probably good. I'm hoping with the Marantz service and parts manual pdf's I emailed them they can narrow down the issue. If the left side output amp is warm and right side output amp is cold while powered up ( as the tech said ) would that indicate anything definative?
Depends how hot. Sounds like the bias is off. Have they checked that? If it is very high that could indicate an issue. If just a little bit high it could just need adjustment. Also would check DC offset coming at the output pin on the amp boards.

It is possible that one channel power amp could stop the relay from clicking even if nothing is obviously blown.
 
Racoon1400 I'm not sure exactly about the bias but I will be sure to ask, but I would think they would know to check if it is a typical issue with most Analog systems but then again I'm sure they arent Marantz experts but what do I know.:confused: I'll give them a couple more days to work on it and hopefully they figure out the issue, after all any technician with the proper documentation and equipment should figure this out right?:eek:
 
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