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Accuphase P-300 Relay issue

fdeelros

fdeelros

AK Subscriber
Subscriber
Hello everyone and happy Easter holiday. I wanted to pick your brains about an Accuphase P-300 that I recently acquired. The unit has two relays (one on each side of the amp close to the front).
The relay on the left (behind the power switch) clicks like crazy when the amp is cold or when I power it up cold for the first time.

The faulty issue causes the speakers to engage & disengage but the clicking fault goes away as the amp warms up. I had an Onkyo receiver once with a similar problem and discovered that the problem was caused by a bad capacitor close to the power supply.

I cleaned the relay and filed it with a nail file and the amp improved a little, however the problem remains, but now on a lesser scale. I am thinking in recapping the entire power supply ( and prolly the amp drivers while I am it :-)) and see if the problem resolves. Any advice? Thanks in advance.
 
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Not sure about your specific relay issue, but I'd not use a nail file to clean contacts. Google 'contact burnishing tool'. Much finer for cleaning contacts. Proper tool for the job. :)
 
Have you calibrated the protect circuit as per the instructions in the service manual?

The protect circuit in these amps can be "iffy" - try recalibrating as per the manual and then you could consider a recap of that board as suggested above. However if you still have issues after calibration there is an analog IC on that protect PCB that fails over time - there is a new replacement - I had to replace this in my P300 and all was well after that.
 
Thanks guys. I am going to check the calibration (DC 0ffset and BIAS) this afternoon and see where they stand. I went ahead and order the caps anyway as it is always a good idea to recap those 30 something years old boads. By the way -@ Slimecity- Do you know the new part number for that failing IC on the protect board that you mentioned? Thanks!
 
fdeelros said:
Hello everyone and happy Easter holiday. I wanted to pick your brains about an Accuphase P-300 that I recently acquired. The unit has two relays (one on each side of the amp close to the front).
The relay on the left (behind the power switch) clicks like crazy when the amp is cold or when I power it up cold for the first time.

The faulty issue causes the speakers to engage & disengage but the clicking fault goes away as the amp warms up. I had an Onkyo receiver once with a similar problem and discovered that the problem was caused by a bad capacitor close to the power supply.

I cleaned the relay and filed it with a nail file and the amp improved a little, however the problem remains, but now on a lesser scale. I am thinking in recapping the entire power supply ( and prolly the amp drivers while I am it :)) and see if the problem resolves. Any advice? Thanks in advance.
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Hi. I have same issue as your. Need to power up and volume down for 10 minutes warm up. After that, no issue listening. I brought c200/p300 last year and amp has fixed circuit protection. I didn't use for 7 months. I use it today and found out issue. Not sure how to fix and find best repair in bay area, CA San Jose area. Any advise or what to do. Thanks
 
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