Honeydripper output low (SOLVED)

[trickpony]

Ok. I have a honeydripper that is built to spec, and was working before I boxed it. Trying to fit it into a 125b, I had to make things tight and ended up scraping the top of 2 of those 4 caps on the top right (next to the 1054) with the output connector when inserting it. I can hear output fine on bypass, but when engaged I hear a very quiet signal (whisper), with some fuzz but no quacking. When I started pulling it back out of the box I got full volume for a second as I was pulling out the pots, but since then back to whisper
I have pulled out all the ic's, reflowed everything, and swapped new ic's in with no luck.  I will take readings tomorrow, but before I do, would the caps have anything to do with this? Should I pull them and check them? I am getting steady 9v into the 1054. The 4558 is showing output of 14-16 V.


Also, I pulled out a pot thinking it was bust because it was measuring 0 , but when I unwired it and tested it was fine. The other measures fine when wired. Both 10kB.  Would this be a bad diiode somewhere?

Arggh, this is such a cool effect, I should have waited for my BB enclosure to arrive.....

Thanks,
Ben

[madbean]

I don't think it is a bad diode. It might be a bad solder joint around that pot. Scraping the cap casings with the jack probably did not damage them unless it was with a lot of force. Since your signal is intermittent I would go with reflowing the solder joints and double checking your wire connections. Try replacing the potentially bad pot if necessary.

[trickpony]

Here are the voltages of the  ICS:
JRC4558
7.34
5.9
0.12
0
0
.12
5.9
7.39
0

Both 3080 are the same:
0
0.1
0.1
0
0
0.1
7.9
0

1054
0.79
0.05
0
0.66
0.83
0.88
7.43
9.15

324N (out side)
0.38
0.38
0.38
7.9
0.117
0.23
0
0
0.27
0
0
0
0.2
0

324N (in side)
0.2
0.1
0.1
7.89
0.1
0.1
0.1
0
0.1
0
0.1
0.1
0.1

All IC's were swapped out and everything was reflowed.

[trickpony]

Ok, well I am just a novice but looking at the schematic I see that I am supposed to have a voltage doubler that acts as Vcc for the other ICs, correct? Well, This is not happening...
Can anyone direct me to what I should check next?  The 2 10uf caps measure fine in circuit. I need to pull the 100uf ones to get a reading.

Thanks,
Ben

[trickpony]

Sorry, my second 1054 that I swapped in was bad...on my last one and now have half of what I need
Leg 2 of the 1054 is now measuring 4.6, then back at the end of  d12 I am getting 13V....should be getting 18V right? I did pull the two 100uf and they were fine.
On the + end of c20 I am reading 9.14V. This is bad right?

Thanks for your time,
Ben

[trickpony]

I am also seeing only 5.1v at the end of r43 (and d15)....This is weird.
Ok, to recap
Where I am supposed to be seeing 18v I see 13,
Where I am supposed to see 10 I see 5
and where I am supposed to see 5 I see 9.14.
Has one of the zeners failed?

[trickpony]

Sorry for the corrections, I said d12 above, actually I should be looking at d13.
I have 9.1V at pin8 of the 1054. Then after d14 its 12.9, then after d13 its 16.4V
Lower than 18 but is it ok?

However after R42 I am seeing 5.1V instead of 10V on the spec.  This I don't understand. r42 measures 3K9, why am I not seeing 10V? Also the output at the +end of d16 is 9.1 not 5....

Help.

[trickpony]

Ok, I am still having no luck on this. Maybe before I go further someone with more electronics knowledge could help me.

Just looking at the (honeydripper) upper schematic that has the voltage doubler:

1) Can I consider this separate from the rest of the circuit, ie do I need to worry about other ICS being bad, other caps and resistors and traces outside of this "power circuit", in the context of why I am seeing incorrect voltages.

2) Should the voltage be doubled at the point where the 1054 loops back into the supply voltage? If so, than since I am seeing additional voltage increase after the second 4001 diode, is this indicating a grounding issue of some kind? (I see 12.9V after first diode, 16.4 after second).

3) I noticed that in TI pdf for the 1054, they tie pin 5 to ground...is that not actually necessary?

Thanks for your time, I am sorry if I seem to be self spamming this thread, I just don't know where to go from here.

Ben

[jkokura]

Wish I could help, but I have no experience with the Honeydripper. It seems like you're working in on the problem well though pony. Hopefully, someone who does have Honeydripper experience can help you out soon, but in the meantime, just keep working those debugging techniques.

Jacob

[trickpony]

OK. Finally found the problem. d16 was shorted.
Looking back, it was of course obvious, and totally makes sense from what I was seeing.
Good news is that I didnt zonk any of my ICS!....
Wacka wacka...

Ben

[trickpony]

And just to close out this thread, I found that the probable reason that the diode died is that I short circuited everything when placing in the box due to using a new part that I really didnt think about.  Tayda sells a
DC Power Jack 2.1mm Panel Mount Bulkhead, that looks nice and attaches from the inside, so that you can put it in the enclosure after you wire. Unfortunately, it is metal and the sleeve is not insulated from the exterior. So when using Center - circuits the sleeve is +, but the sleeve of the input is connected to ground and also uninsulated...so I short everything through the enclosure....arggh.