Harbinger one lamp issue

[HailToTheBlues]

Hi guys,
So i had my harbinger working for a couple months now, not perfect yet tonewise, i think i might change it's photocells. But today, when i was jamming a bit using my pedalboard, i noticed the harbinger had stopped working, and the rate led was not blinking. I opened it and as it was obvious, the lamp was not blinking either. When i decrease the speed knob, the only thing that happens now is that the lamp loses a bit of brightness more or less from 10 0'clock, to the lowest speed. So, anyone knows what might be causing this sudden issue? Can it be an active part that broke? If so, some voltages might be useful, so where would i start, if that's necessary?

Best regards

[TGP39]

Have you tried playing with the offset trimmer to see if you can get the lamp to blink again? Just a thought.

Steve.

[HailToTheBlues]

I tried that, but the result was the same, it doesn't blink as it used to. I noticed that when i plugged the dc power, the lamp "flickered" a bit before it stabilized, don't know if that indicates something in particular. Well, any thoughts?

[HailToTheBlues]

So, any thoughts guys?

[madbean]

I would take some cursory voltage readings at least. See if you are getting 18v to the audio section and 15v to the LFO. You can measure this by checking pin8 of the charge pump and the output pin of the 15v regulator.

There are a couple things that could cause the LFO to stop working. Obviously, dodgy solder joints especially on the dual gang pot. One of the three 1uF electrolytic caps in the LFO section could be toast. Or, it could be something else. One trick you can try after verifying the voltages is unlpug the DC power, wait a minute or two then short the output pin of the regulator to ground then then input pin to ground drain all the caps. Then plug the DC power back in and see if the LFO starts to work.

[HailToTheBlues]

Thanks for the answer Brian. So i checked the voltages, with the pinout of the image i attached, if it is correct, then Pin 8 has only 9v. I also noticed something strange that maybe is normal, which was when i tried to measure the voltage of pin 1, the lamp turned off, and it gave me 0,9v. The regulator is fine, 15v. I also tried to drain the caps, as you suggested, and if i have done it right, it didn't help, i used a short wire, and touched each lead with the other end touching ground, i didn't solder. So, any suspects?

[madbean]

Sorry, I meant check the 18v reading on the second 1n5817 diode. 9v on pin8 is correct. But, since you are reading 9v on pin8 and 15 on the regulator then the voltages are fine. Don't worry about the thing with touching the DMM to pin1...probably just created a voltage divider with the DMM or something.

Which version is this...the 2015 or the one before?

[HailToTheBlues]

Sorry, I meant check the 18v reading on the second 1n5817 diode. 9v on pin8 is correct. But, since you are reading 9v on pin8 and 15 on the regulator then the voltages are fine. Don't worry about the thing with touching the DMM to pin1...probably just created a voltage divider with the DMM or something.

Which version is this...the 2015 or the one before?

Okay then. I think it's the previous version, before you made those layout changes on the last.

[madbean]

Do you have an external LED indicator for the LFO? If so, try shorting the + side of the LED to the - side to short the 4k7 resistor to ground. Does that start the lamp?

[HailToTheBlues]

Do you have an external LED indicator for the LFO? If so, try shorting the + side of the LED to the - side to short the 4k7 resistor to ground. Does that start the lamp?

If your talking about the rate led, i have one, but i tried that and it didn't change anything, the bypass led didn't change anything by doing that either, in case i was misunderstanding your indications.

[HailToTheBlues]

The weirdest thing in this situation, is that it has been working normally for months, and then suddenly it stopped working, so i'm thinking something broke or burned there, that is the only explanation that i can think of.

[HailToTheBlues]

Any clues of what might be causing it?

[luks999]

hm maybe a tranny fried?
maybe the lamp driver?
ive only had such thing with the neovibe when i wired my speed pot wrong... lamp light but wasnt blinking
any news on this?

[HailToTheBlues]

hm maybe a tranny fried?
maybe the lamp driver?
ive only had such thing with the neovibe when i wired my speed pot wrong... lamp light but wasnt blinking
any news on this?

I forgot to update this post. The problem solved on it's own, it started again without me doing anything, and it's still working without any issues, so i'm still confused, and waiting for it to let me down again (hope not). Thanks for the reply, thought.

[Strassercaster]

good luck. if you socketed a few components maybe they got hit and started making contact. check for connections. if it happens again check q13