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If you mean what suffix? No, that was the alphabet soup I refered to. When I need some, I just look at the available ones for the shape I need. Usually either DIP8 or SOIC. Whatever suffix that results in is what I order. DImensions are on the data sheets.
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Education is what you're left with after you have forgotten what you have learned. -
There were two different size 4580's but were very close in the diminsions. I measured the original and of coarse it's metric. The op amp is so small I was wondering what you have used in the past. The data sheet had the old name JRC on one side of the page and on the other end had NJM. Same company, just the name had changed. I guess. Should be part number 513-NJM4580E. And this is from Mouser. Did you see the two bad 4580's I had in a previous post ? I guess that I measured it the right way. It was the only two on the entire main board with those readings and the bad IC's are in the circuit that I'm having problems with. Thanks....Comment
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Yes, I saw those, that was why I mentioned making sure there was no DC on the input pins when the pads are empty. Very unlikey the problem is not the IC though,
New Japan Radio Company - NJR, JRC, same place. I think JRC is one of the brands of NJR. Like Chevy is to General Motors.
Metric? No sweat. You have a Harbor Freight nearby? Look up their cheap plastic micrometer. Two bucks. I have one, works fine. I have a similar one I have been using for 30 some years. Just the thing to find out if the pots you are looking at are 12mm, 16mm, 24mm or whatever, or the tiny tactile pushbuttton is 6mm or 12mm, or what size your op amp might be. Or google plastic micrometer - sold all over, and cheap. And darn useful.
6" Utility Caliper
The E package is probably OK, I usually look for SOIC, but not every maker uses that term for the same shape. Just look up the overall dimensions and the lead spacing.Education is what you're left with after you have forgotten what you have learned.Comment
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What would be a bad DC reading on the + and - input Pins ? Thank you....Comment
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Well, probably any at all, unless the exact same amount was on both the invert and non-invert input pins. But really all I am looking for - and not really expecting anyway - is something like several volts or more. I won't worry about a few millivolts or something.Education is what you're left with after you have forgotten what you have learned.Comment
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Hi Guys!
First sorry for hijacking the post about outputs, but i have a question regarding the same desk with different problem. Today i've bought SL2442FX pro in quite a bad shape. Everything except DSP seems to be working. There is E1 error shown on right effect display (immediately after power on). The left (DSP1) display is blank. Can somebody please point me in the right direction? I have some experiences in electronics and i'd like to work on that desk in my spare time just for hobby/pleasure. Also the service manual would be nice but haven't found any on the web so far.
Thank you for your help,
peterComment
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Hi Peter, welcome to the forum.
DOn;t be sorry about hijacking a thread, just don't hijack one. Threads are free, start a new one for your board, and we'll help you. That way no one will be confused as to what we are working on.
Pull your DSP board off and then put it back. That will refresh the connector contacts. CAn;t hurt, might help.Education is what you're left with after you have forgotten what you have learned.Comment
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I measured the empty pads for IC 39 and 44. The test was done with no signal input. Here are the results....
IC 39
Pin 1 = .009 Vac (-.000 Vdc )
Pin 7 = .046 Vac ( .076 Vdc )
Pin 8 = +14.76 Vdc
Pin 4 = -14.67 Vdc
Pin 2 = .007 Vac ( .000 Vdc )
Pin 3 = .001 Vac ( .000 Vdc )
Pin 5 = .023 Vac (+1.9 Vdc )
Pin 6 = .034 Vac (+1.3 Vdc )
IC 44
Pin 1 = .003 Vac ( .000 Vdc )
Pin 7 = .003 Vac ( .000 Vdc )
Pin 8 = +14.73 Vdc
Pin 4 = -14.67 Vdc
Pin 2 = .002 Vac (.000 Vdc )
Pin 3 = .001 Vac (.000 Vdc )
Pin 5 = .001 Vac (.000 Vdc )
Pin 6 = .002 Vac (.000 Vdc )
Is the stray DC voltage on pins 5 and 6 of IC 39 OK ? Thanks....Comment
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As per post #24, I went back and checked IC 53 with the IC in place....
IC 53
Pin 1 = .000 Vac (.000 Vdc )
Pin 7 = .000 Vac (.000 Vdc )
Pin 8 = +14.73 Vdc
Pin 4 = -14.66 Vdc
Pin 2 = .001 Vac (.000 Vdc )
Pin 3 = .001 Vac (.000 Vdc )
Pin 5 = .001 Vac (.000 Vdc )
Pin 6 = .001 Vac (.000 Vdc )
Thanks for your help....Last edited by Twistedpair; 10-31-2010, 05:42 PM.Comment
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Looking at the schematic, It looks like the voltage on input pins 5 and 6 would be normal unless the control line balance's out these two pins thus pulling down the output on pin 7. Is this how IC 39 works ? Anybody....Thanks....Attached FilesComment
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I guess no one like's Behringer too much and I can see why. They are a PIA to work on. However, I'm trying to move forward with my troubleshooting, so any input from anyone would greatly be appreciated. If I could get an answer to post #38 on page 2, your answer would be helpful. Thanks to anyone for your help....Last edited by Twistedpair; 11-01-2010, 07:35 PM.Comment
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IC39b is a control driver for the PFL or Solo or something. It is not in the signal path. The output is intended to snap between two DC states depending up- on if buttons are pushed or not. I am sorry if I led you wrong there. I seem to recall IC44 and 53 as being break points in the signal.
This big Behr mixer is not much different from anyone else's big mixer once you have a schematic.Education is what you're left with after you have forgotten what you have learned.Comment
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You didn't lead me wrong Enzo, it was my blind troubleshooting, although I'm getting some practice soldering the SMT chips. Really small stuff. IC39 and 44 have been replaced with new 4580's. I will try out the board with the new 4580's shortly. I have the main board, input jack board and power supply out of the chassis and on the work bench. Channels 1-16 are still in the chassis. For further checks, will a signal input into the CD jacks be ok for now. I know early in the post you suggested an input signal into one of the regular channels. Maybe IC44 was the problem. Thank You !!!!Comment
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The master board includes a few input channels, so why not use them? 1-16 are left behind, but the master still has 17-whatever right on it. The reason I prefer that is that we know what a regular input channel ought to sound like, and that it will have reasonable levels. It will be fully assignable to subs and mains, plus it can send to all the AUX buses. And it hits the master section from the beginning, not a doorway halfway down the hall, so to speak. Frankly when I encounter a mixer with tape inputs and outputs I never really know WHAT to expect them to do. SOme work like line inputs, while others seem to want more signal level than my speakers.Education is what you're left with after you have forgotten what you have learned.Comment
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I finally got to check what has been done so far and with good results. The main outs and mono are working now, however when engaging the pushbutton on the mono channel for the low pass filter, the volume drops off to a very low level. Without the low pass filter engaged, the volume level is great. I will go back and check my readings on IC34. My previous readings on IC34 were ok...Thanks....
PS: I forgot to mention that channels 1-16 Line-In's all work and during the above testing, the signal was to channel 1. I haven't tested the In's and Out's of anything else yet but I intend to do that soon....Last edited by Twistedpair; 11-04-2010, 04:15 PM.Comment
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