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snake
Copper Member
Mexico
5 Posts |
 Posted - 07/18/2006 : 02:45:21
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greetings everyone,i just want to share the solution to the problem on my phaser ph-1  :
malfunction.-plugged normally (guitar-in,output-amp)there`s no signal,on bypass mode or effect on(or should i said=led on/off normal)muted completly.
as usual replace both ic`s jrc4303 with a pair of lm324 and tl074,without any change at all, replace all the electrolitic capacitors and nothing,even test everyone of the diodes,one by one,all of them:"normal"cristal diodes,rectifier diode and the zener diodes,according to my multimeter all the readings look normal, here is when i request the schematic here to the boss area forum,because i was walking in circles and nothing.
with the schematic at hand proceed to check and recheck the componentes that i replace/check before.
then i see where i was missing,the zener diodes,i forgot to check the voltage with the zener diodes in place,one of the zener diodes was near at the indicator led which i don`t tested with the multimeter,because the led worked right and responded well with the action of the switch.
the other zener to ground(voltage=5.1volts) located after the first opamp section,with the multimeter read the 8.6volts of the battery 
not totally sure if this was the main problem, proceed to replace the diode zener with one of 5.6volts which i had in my box.
plug everything again,and work at the first try  bypass mode=guitar loud and clear,effect on=soft and crystal swaying with no distortion at all.
the zener in question is d3 marked 5.1v,
I really want to thank again to lightburst for the schematic.
I hope this information will be useful to someone who had the same problem with a boss ph-1.
Thanks to the boss area forum i resolve this issue and just took me 6-7 years
p.s sorry for my english |
Edited by - snake on 07/18/2006 02:48:02 |
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lightburst
Silver Member
Germany
158 Posts |
Posted - 07/18/2006 : 09:50:08
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Glad I could help and thank you for your report. In the future I will keep an eye on those zeners  |
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Basstyra
Gold Member
France
523 Posts |
Posted - 07/18/2006 : 12:42:00
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Yep... Allways verify the alimentaion and the bias first. That's kinda my golden rule when I repair stuff.
Plus, depending on the design, Zeners can be put pretty close to their max admissible power. Therefore they could suffer from a too high voltage. If you powered (you or someone else) your pedal with 12 instead of 9v, it could have been enough. |
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snake
Copper Member
Mexico
5 Posts |
Posted - 07/20/2006 : 04:03:50
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| Thanks for the advice,Basstyra.I will try not to forget that tip from now on |
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boss phaser ph-1-working!!!!!solution inside
