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2270 power amplifier boards R & R

rustyhusky

rustyhusky

Member
Ok, I admit it. I'm a glutton for punishment. After rebuilding a 2265B, I'm taking on my cousins 2270.

The first thing I've noticed is that the older 2270 is much less service-friendly than the 2265B. Getting the two power amp board/heatsink assemblies out is nothing short of a $@&%!!!

A big advantage I had when working on the 2265B was the ability to create some "jumper cables" so I could work on and troubleshoot the power amplifier assembly outside of the chassis. I would like to do the same with the 2270, however the wiring harnesses are soldered directly to the boards.

Has anyone attempted to wire in some quick disconnects to the 2270 power amplifier boards using Molex or other similar connectors?
 
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I’m sure you could, but I would want a really tight connector, since Molex can be a little sloppy. You’re talking about the Molex type as is used in a computer? What did Marantz use for connectors on later units? You should be able to purchase something like those.
 
Welcome to AK!

The 2270 main amplifiers can be rebuilt in place by removing the heat sinks. None of the leads have to be removed. You can do a certain amount of troubleshooting with them this way but it takes care not too let anything short out. And if it needs to come out, then it is easier to remove the leads after the heat sinks are out. With practice it becomes easier to remove and reinstall the 2245/2270 amps. With care, the original leads can all be used without replacing or extending the leads.

2270 right amp w heatsink removed_resize.jpg

If completely removed, you can work on the amp outside the chassis using as many test leads as needed going back to the leads in the chassis. Be sure to be using a dim bulb tester while you are running the amp outside the receiver. Or pretty much any time you are working on it.

This 2270 amp is being powered off the receiver, while using a signal generator and scope instead of the inputs and outputs to the receiver.But you can connect back to the input and outputs on the receiver too.

test leads.jpg 2270 amp on bench powered by receiver.jpg

With a bench power supply, signal generator, and oscilloscope, the amp can be worked on independently of the receiver.

2270 amp on bench.jpg
 
cemerson said:
I’m sure you could, but I would want a really tight connector, since Molex can be a little sloppy. You’re talking about the Molex type as is used in a computer? What did Marantz use for connectors on later units? You should be able to purchase something like those.
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Molex has a whole slew of connector types. I'm looking at using pairs of "Micro-Fit 3.0" connectors. They're good for 8.5A and I can get gold plated male/female pins.

As for the connectors on my 2265B, they are nothing special. The female connectors were several plated "U" shaped sockets that pins on the circuit board plugged into. Honestly, I think the gold plated Molex connectors I'm looking at are much more secure. They have integral latches so they can't come apart easily.
 
Seems like overkill TBH. Great idea, don't get me wrong ...but, just 'jumper cable' the board to test/troubleshoot and then solder them back in place when you're done.
Once you're finished no one should be back inside for another 40 years, right? :cool:
 
KeyserSozee said:
Seems like overkill TBH. Great idea, don't get me wrong ...but, just 'jumper cable' the board to test/troubleshoot and then solder them back in place when you're done.
Once you're finished no one should be back inside for another 40 years, right? :cool:
Click to expand...
It's the soldering back in place that's the problem. The space is tight between the terminals and the chassis and it would be difficult without damaging other wires. I could probably add extensions though......
 
If you do end up unsoldering the wiring I'd avoid adding extensions. A tip for you is to redress the heat damaged ends of the wires that were unsoldered. It will happen to the most experienced of us! Gut back any flared out insulation on the wire ends and fit a piece of heat shrink tubing on to make up the lost insulation. It looks nice too and nice counts in my book!
 
rustyhusky said:
Ok, I admit it. I'm a glutton for punishment. After rebuilding a 2265B, I'm taking on my cousins 2270.

The first thing I've noticed is that the older 2270 is much less service-friendly than the 2265B. Getting the two power amp board/heatsink assemblies out is nothing short of a $@&%!!!

A big advantage I had when working on the 2265B was the ability to create some "jumper cables" so I could work on and troubleshoot the power amplifier assembly outside of the chassis. I would like to do the same with the 2270, however the wiring harnesses are soldered directly to the boards.

Has anyone attempted to wire in some quick disconnects to the 2270 power amplifier boards using Molex or other similar connectors?
Click to expand...

Hello, I'm brand new to AK and seeking tech help. I have a Marantz 2270. It worked fine but I managed to make it blow a fuse. I was trying to record vinyl to digital and had a line from REC OUT on the MZ to laptop line in. While the MZ was on, I unplugged the 3.5 jack from the laptop (stupid I know) and the MZ popped and went off. I replaced the fuse and hit the power button. It came on for about 3 seconds and then went off. I checked and the fuse wasn't blown. I'm afraid I may have fried a lot of stuff inside the MZ. I'm wondering if anyone out there takes on diagnostics and attempted repairs of things like this? It is a very nice unit and I'm hoping I didn't ruin it beyond repair. It has never been recapped or anything else. I'm totally non-technical and couldn't attempt this myself. I'm willing to send the unit with the understanding it may not be fixable. Thanks in advance. Robert
 
Robert Welch said:
Hello, I'm brand new to AK and seeking tech help. I have a Marantz 2270. It worked fine but I managed to make it blow a fuse. I was trying to record vinyl to digital and had a line from REC OUT on the MZ to laptop line in. While the MZ was on, I unplugged the 3.5 jack from the laptop (stupid I know) and the MZ popped and went off. I replaced the fuse and hit the power button. It came on for about 3 seconds and then went off. I checked and the fuse wasn't blown. I'm afraid I may have fried a lot of stuff inside the MZ. I'm wondering if anyone out there takes on diagnostics and attempted repairs of things like this? It is a very nice unit and I'm hoping I didn't ruin it beyond repair. It has never been recapped or anything else. I'm totally non-technical and couldn't attempt this myself. I'm willing to send the unit with the understanding it may not be fixable. Thanks in advance. Robert
Click to expand...

Robert Welch said:
Hello, I'm brand new to AK and seeking tech help. I have a Marantz 2270. It worked fine but I managed to make it blow a fuse. I was trying to record vinyl to digital and had a line from REC OUT on the MZ to laptop line in. While the MZ was on, I unplugged the 3.5 jack from the laptop (stupid I know) and the MZ popped and went off. I replaced the fuse and hit the power button. It came on for about 3 seconds and then went off. I checked and the fuse wasn't blown. I'm afraid I may have fried a lot of stuff inside the MZ. I'm wondering if anyone out there takes on diagnostics and attempted repairs of things like this? It is a very nice unit and I'm hoping I didn't ruin it beyond repair. It has never been recapped or anything else. I'm totally non-technical and couldn't attempt this myself. I'm willing to send the unit with the understanding it may not be fixable. Thanks in advance. Robert
Click to expand...
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