Strange Boss issue - Help pls!

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mothershipzeta
PAT. # 2.972.923
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Strange Boss issue - Help pls!

Post by mothershipzeta » Fri Oct 13, 2017 3:28 am

So I snagged an old '80s PH-1r from ebay after playing a borrowed one for a while, and slowly falling in love with it.

Well it arrived, and didn't quite work.

It produced the gorgeous phaser sound for maybe a minute, then the effected signal faded out together with the LED, and all that remained was my dry signal when the pedal was turned on. Thinking that this was a cap issue (even though there were no visible signs of faulty caps), I quickly changed all the electrolytics on the PCB, and just as I thought the problem got a whole lot better. Now the effect doesn't fade out, it stays on for as long as I want it to, but part of the problem remained: The LED light dims approximately after 5 mins when the pedal is on. After changing all the coupling caps and filter caps, I have no idea what could cause this. I even carefully looked over the board to see if any two components' legs are touching, but I didn't find any.

Any help would be appreciated if someone has an idea of what's going on!
Here's the schematic for reference: http://www.geofex.com/FX_images/Boss%20PH-1r.pdf" onclick="window.open(this.href);return false;

Meanwhile I'm in talks with the seller for a partial refund (of course the listing didn't mention anything - EXCELLENT L@@K!, and all that).

THANKS guys&gals you're the best
indulj már, hé / embermlék / önmagától gyulladó fény!

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mothershipzeta
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Re: Strange Boss issue - Help pls!

Post by mothershipzeta » Fri Oct 13, 2017 3:41 am

Oh yeah, one thing I didn't mention, is that I'm powering it from a battery (fresh, checked, it doesn't drain it), because this requires one of those old ACA adapters, which I don't have, and haven't converted it to use regulated 9V yet.
indulj már, hé / embermlék / önmagától gyulladó fény!

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shoule79
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Re: Strange Boss issue - Help pls!

Post by shoule79 » Fri Oct 13, 2017 6:38 am

If you have another, newer Boss pedal you can daisy chain it to the PH1 to it to rule out a power issue. I do this to power my old Boss pedals on the board.

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mothershipzeta
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Re: Strange Boss issue - Help pls!

Post by mothershipzeta » Sun Oct 15, 2017 12:23 pm

I think I got the issue sorted: I tried it with 9V through a daisy chain with another boss pedal connected, also tried running it on 12V as the PP2+ manual suggested, but it didn't turn on either way, so I went ahead and removed and jumpered the extra resistor and diode that stepped down the voltage from the adaptor, and got it working this way from a regular 9V center negative power supply. I didn't pay attention to the LED that much during playing, so I can't say if the dimming issue is solved, at this point I'm just glad I can use it on the board at last.
indulj már, hé / embermlék / önmagától gyulladó fény!

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