2016-01-12 21:49:32 +00:00
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date = "2016-01-12"
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title = "Denon PMA-560 Repair Log - Update"
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tags = ["ohmexpress", "repair", "audiorepair"]
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2017-09-11 12:20:15 +00:00
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categories = [ "Audio Repair" ]
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2016-01-12 21:49:32 +00:00
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description = "Replacement parts for the Denon PMA-560 have arrived. Let's get to work!"
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slug = "denon-pma-560-repair-log-update"
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+++
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Last week I diagnosed a Denon PMA-560 Integrated Stereo Amplifier. The device worked fine
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since its production in 1990, but had lost output on the left channel. My diagnosis, as
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you can [read in the previous repair log][repair-log] was a defect in the A-Channel
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relay.
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## There and back again
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It sounds straightforward: just replace the A-channel relay. And it is. But does require
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a bit of work and careful deconstruction of the unit.
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2016-01-12 21:57:31 +00:00
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Those are the original relays. On the left you can see some metal pins connected to the
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PCB, those are the speaker terminals that you can see protrude out the back. This PCB is,
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2016-01-12 21:49:32 +00:00
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on one side, firmly pressed against the back panel of the case and other the other side
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wedged in by the big transformer. The PCB itself is held in place by three white plastic
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pins. Can you spot them?
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To remove the PCB, as I need to do some soldering work on the bottom side, I'd need to
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2016-01-12 21:57:31 +00:00
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remove the back panel, which amounts to 15 screws. After that, the PCB comes loose and
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2016-01-12 21:49:32 +00:00
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the soldering iron can be heated up.
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## Replacement
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The first problem is that the schematic in the service manual sports two RL602 devices.
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I've marked the three relays in green. RL601 and RL602 are for the A and B speaker channels.
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The second relay also RL602 in the schematic is for the headphones. Luckily this relay
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has different size and shape and is correctly marked as RL603 on the PCB silkscreen.
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The relay has six pins, which are soldered to the PCB. Using my soldering iron and
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desoldering pump I first removed most of the solder and then wiggled the relay free
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while quickly heating up each pin.
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Next up, insert new relays and solder it to the PCB.
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Here is the new relay in place. As you can see it's the same make and model as
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it's malfunctioning predecessor.
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Let's get the PCB back in, re-attach the back plate and hook the unit up to some speakers
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and input.
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## Moment of truth
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Yes. It worked. Turn on some music, select the correct input, select A-channel speaker output
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and slowly turn up the volume to the voice of Adele.
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After this I did a double-check that I reconnected all wires and put the device back
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together (including the 15 screws on the back, not counting the three for the top cover).
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Here is the restored Denon PMA-560 Integrated Stereo Amplifier, fully tested and working.
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[repair-log]: /2016/01/07/denon-pma-560-repair-log/
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