Counterpoint Natural Progression Turn On Problems


I have a Natural Progression NP 100 Gold Upgrade amplifier that will not turn on. When working properly, from the stand-by mode, you press the power on button, it goes through some type of verification process and then after a minute or so it turns on. However, since three years ago, and in the summer only, it would sometimes end up not turning on or taking much longer than ususal. I chalked it up to possible brown-outs, but it has gotten progressively worse and now will not power up from stand-by at all. I have seen a similar one for sale with the caveat that it wouldn't turn on when the temperature was above about 72ºF. The owner put ice packs on it to turn it on when that happened. I have not tried this. Does anyone have any idea what can be wrong (ie thermal protection circuit?) and who or where can it be fixed? I now live in Europe so if you have any clues for overseas repair, great, if not I'll have it sent to the US. Thamks!

Ag insider logo xs@2xsquitti

With an amp that old who knows you should get it checked out anyway a once over and maybe a recapping are in order.

What you are describing is too dramatic

NP100s are extremely reliable and they are not that old


the turn-on timer is triggered by a 555 timer that derives power from the 6.3v filament supply.
pull out 1 of the 6sn7 tubes and see if it turns on after 60 seconds and stay on

if so you may have either a tube that has a filament shorted therefore drawing too much current. Or a filament supply cap 16v 10000uf that has deteriorated, or one of the white 3ohm drop resisters next to the filament supply caps that have bad solder joints.

there is no thermal protection on the np100, only a thermal bias reducing circuit that doesn’t cut off as dramatically as pulling standby or not popping to “green” operating mode.

there is enough urban folklore on counterpoint SA amps and NP amps it’s disgusting. No putting an ice pack will only get the amp wet and explode. Do not attempt!

I have SA 20 that's been upgraded (?so SA220?) with similar issues--began few weeks ago, goes to standby for minute or two, then blue light comes back on--no issues with the sound it's producing.  Yesterday, would not turn on--no red light, etc.  Tried again 30" later, and it operated normally.  (hen it wouldn't turn on, had not been running for couple days--i.e., was not hot, etc).  Looking for knowledgeable repair person in SF North Bay area...

@johnsonwu gave you some good thoughts.  Shipping it to the US is likely prohibitively expensive so I’d make a new post here and ask if someone knows a repair guy in your area, or even quite a bit further.  I had the same thing happen to my McCormack amp and it was a faulty input board that’s very difficult to fix if you can even find someone to do it.  Just another potential issue to consider, and best of luck. 

It’s always the timer circuit in these older NP100s

just a cap and the 555 timer

a competent tech can identify it right away But these days cap swappers are common, competent techs are rare.

NP220s... maybe the rocker power switch in the front, too much current makes them fail every few years. You can even get those at Lowes or Home Depot.

 

drsommer I am in Sunnyvale.  But most likely you can fix your unit yourself without having to haul it around.
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