madbeanpedals::forum

Projects => Tech Help - Projects Page => Topic started by: miter53 on February 09, 2014, 01:23:56 AM

Title: not another pork barrel troubleshooting thread! Need advice...[Huzzah! Fixed!]
Post by: miter53 on February 09, 2014, 01:23:56 AM
Okay, I'm ready for some help. The output is completely dry. Inspected and reflowed all (I think!) the pads. LED varies in intensity and rate as expected. I swapped the 3007 for a tested one, but only have the one 3101 on hand. The voltages seem funny on 2 and 4. Any suggestions? I'll post some pix in a bit.

TL062
1: 0.67 - 8.5
2: 4.4 - 4.8
3: 2.5 - 6.4
4: 0
5: 4.4 - 4.8
6: 4.8
7: 2.5 - 5.6
8: 9.19

JRC4558D
1: 6.83
2: 6.83
3: 6.83
4: 0
5: 6.83
6: 6.83
7: 6.83
8: 9.19

MN3101
1: 9.19
2: .001 ??
3: 0
4: .001 ??
5: 0.67
6: .001
7: 6.5
8: 1.2 drifts towards 0

MN3007
1: 9.19
2: .001
3: 6.09
4: 1.2 drifts towards 0
5: 0
6: 6.53
7: 6.83
8: 6.83
Title: Re: not another pork barrel troubleshooting thread! Need advice...
Post by: miter53 on February 10, 2014, 08:27:44 PM
(http://imageshack.com/a/img513/5926/a0tp.jpg)
(http://imageshack.com/a/img844/4395/usqv.jpg)

Pay no attention to the disconnected in/out wires...
Title: Re: not another pork barrel troubleshooting thread! Need advice...
Post by: jkokura on February 10, 2014, 08:32:50 PM
Do you have a probe? Are you getting output on the BBD?

Jacob
Title: Re: not another pork barrel troubleshooting thread! Need advice...
Post by: Scruffie on February 10, 2014, 09:05:55 PM
I very much doubt it as it has no clock to work with.

You were right to suspect the MN3101, it's way off, rest looks fine.
Title: Re: not another pork barrel troubleshooting thread! Need advice...
Post by: Clayford on February 10, 2014, 10:56:21 PM
Yup - and damn.
Dale  mil-spec resistors
Wima box caps
Sprague caps
milled sockets
Highend replacement for the tl062...

And none of us managed to use sockets on the trannys when we built them. Get a replacement MN3101 and she should fire right up!

Title: Re: not another pork barrel troubleshooting thread! Need advice...
Post by: mattlee0037 on February 10, 2014, 11:39:15 PM
What are the resistors that look like Dales but have the regular bands on them? Are those also Dales?
Title: Re: not another pork barrel troubleshooting thread! Need advice...
Post by: Clayford on February 10, 2014, 11:41:28 PM
I think? This thing is (almost)ready for war! I like it. I prefer cheaper parts than he's chosen here but man it's nice.
Title: Re: not another pork barrel troubleshooting thread! Need advice...
Post by: miter53 on February 11, 2014, 12:45:57 AM
Those are Dales too. They're not too pricey in quantity from Mouser and/or Allied. I usually figure parts for the most part are pretty cheap compared to the time spent building. Although I did try to go cheap-ish on the ICs. Got both the MNs from Doctor Tweek in the UK. I've ordered a 3101 from SB now lol...we will see what happens! Thanks all.
Title: Re: not another pork barrel troubleshooting thread! Need advice...
Post by: Govmnt_Lacky on February 11, 2014, 01:05:52 AM
Last ditch effort...

From the looks of your pics, it looks like your 3101 is not fully seated in the socket. Especially the Pin 1-4 side. Look there.

Also... since it is presumed dead anyways... try lifting Pin 4 of the 3101 out of its socket and reinsert with all the other pins making contact and see if you get anything. I once had a problem with a CE2 build and I read somewhere that lifting Pin 4 of the 3101 could fix it..... and it did!

Give these both a try and let us know.  ;)

EDIT: Yes... Scruffie is correct below. It is Pin 8 of the 3101. Try lifting Pin 8.
Title: Re: not another pork barrel troubleshooting thread! Need advice...
Post by: Scruffie on February 11, 2014, 02:03:18 AM
I didn't mean to imply the chip was definitely dead, merely that's where the issue lies so yes give lacky's ideas a go, I too remember the pin lifting 'trick' but I don't think it was pin 4 as that's a clock pulse we need... not sure which pin it was... probably 6, 3 or 8.

And you've checked it's all soldered nicely? I did wonder about pin 8 dropping, that should be the V.Ref pin so I wonder if C12 is soldered correctly too or if it is just the 3101.
Title: Re: not another pork barrel troubleshooting thread! Need advice...
Post by: miter53 on February 11, 2014, 05:44:02 AM
Fwiw, touched up C12 pads, tried lifting pins 4, 6, 3 and 8 in turn, no change.
Title: Re: not another pork barrel troubleshooting thread! Need advice...
Post by: Clayford on February 11, 2014, 06:17:47 AM
(http://i.imgur.com/RcK8rXx.png?1)
Title: Re: not another pork barrel troubleshooting thread! Need advice...[Huzzah! Fixed!]
Post by: miter53 on February 19, 2014, 03:59:38 AM
Bad 3101 confirmed...SB to the rescue. Thanks all!
Title: Re: not another pork barrel troubleshooting thread! Need advice...[Huzzah! Fixed!]
Post by: Clayford on February 19, 2014, 03:11:07 PM
(http://www.crankyandjaded.com/img/frankenstein.jpg)
Clearly - I'm stoked for you.
Congrats!
Title: Re: not another pork barrel troubleshooting thread! Need advice...[Huzzah! Fixed!]
Post by: icecycle66 on February 19, 2014, 03:25:44 PM
Where do you get those awesome little sausage resistors?
Title: Re: not another pork barrel troubleshooting thread! Need advice...[Huzzah! Fixed!]
Post by: miter53 on February 19, 2014, 04:45:18 PM
They are Vishay-Dale mil-spec metal film. Got them either at Mouser or Allied. A little pricey, but there are some really good deals available at Allied in some values, and Mouser is ok if you buy in quantity.