Thread: Philips N4450
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Old 13th Aug 2017, 4:04 pm   #46
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Location: Croydon, Surrey, UK.
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Default Re: Philips N4450

Quote:
Originally Posted by TonyDuell View Post

I probably won't have too many problems with the PSU.
The rectifiers used to fail on these with monotonous regularity. They are BY164 types and the official Philips mod was to fit one more in parallel with each so there were four in total (eight altogether). The advice was to drill 1/32" holes alongside the existing ones to take the extra BY164's. No more problems after that.

Quote:
Originally Posted by TonyDuell View Post
And today's lesson is 'Don't cut corners!'.

Having got the amplifier back together I tested it to find it was dead on one channel. An imput signal got as far as the monitor socket but no further. Testing signals on the amplifier motherboard suggests more potentiometer trouble.
I seem to recall that the 'A-B switch was troublesome. Back in the day, I just used to replace them. Now you may have to remove the slider and use switch cleaner sparingly. If you remove the slider, note that one end is tapered. Insert the slider tapered end first....that taper opens the internal contacts otherwise the contacts will be wrecked.
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