Completed Project STANDBY mode voltage fluctuation in Heathkit IP-17

Thread Starter

Rahulk70

Joined Dec 16, 2016
536
Hi folks,

It maybe that the IP-17 is just like that or it's malfunctioning, not really sure. I noticed that when both the C- & B+ voltage knobs are at min and the DC switch is turned ON it rises to like 25V and then slowly drops back to 0V in a few seconds.

So, now if I switch back to STANDBY then the voltage quickly goes to like -14V then rises back to 47V and then slowly drops back to 0V.

Is this a common phenomenon with the IP-17 or something is going bad inside?

Here is a video of the issue I have shot an posted for better understanding. I have a feeling it could be the caps that are discharging slowly?
In the first part I've used a load resistor to see if it is able to absorb the voltage fluctuation.


Also I found the same issue on another video posted by another person sometime ago but on an IP-2717A, timing from 3:43 to 4:24 to see the issue:

 

danadak

Joined Mar 10, 2018
4,057
Is V set pot when wiper at mechanical extremes making poor contact with
end of resistor track contact ? Clean it with DeOx or similiar contact cleaner.

Any polarized caps inside bulging or leaking ?


Regards, Dana.
 

Thread Starter

Rahulk70

Joined Dec 16, 2016
536
Is V set pot when wiper at mechanical extremes making poor contact with
end of resistor track contact ? Clean it with DeOx or similiar contact cleaner.

Any polarized caps inside bulging or leaking ?


Regards, Dana.
Do you mean the C- & B+ pots? The C- pot was quite hard to turn in the beginning, so after spraying some CRC co-contact cleaner into the pots its very smooth now. The voltage for both the knobs when at minimum has the outputs at 0V, both on the panel and when measured with a multi meter.

No, the caps are fine. Had replaced electrolytic and paper caps too. Also the 680K resistor that was out of value so replaced that too.
 
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