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LVRALPH
Fireman
5431 Posts |
 Posted - 07/04/2012 : 04:40:10 AM
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Well, the DCCOD's arrived at Marc's on Monday and on Tuesday an answer appeared in my mailbox! How is that for customer service! I was not expecting an answer for at least a week!
Marc found some soldering issues, which really bugged me. I examine closely all boards after I build them under magnification (Optivisor) and missed the issues he brought up. I will have to be a little more diligent.
He mentions that my flux might be causing an issue. I have been using a water based flux that was recommended. Even though I spray the board generously with flux remover and scrub it vigerously with my wife's toothbrush, most of the flux residue remains. I am thinking of removing the IC and scubbing the board under hot water, then using a hair dryer, dry the board and replace the IC. This is because the flux is stubborn to remove. But I don't know if that would be bad. I will ask Marc.
I have posted his response below as well as some very helpful pics he sent to me. I hope all you can learn from my troubles.
Hello Ralph,
I got your boards today and have figured out what has caused issues.
-Both boards had a part where the pad was missing and the part was clipped flush with the board.
-Both boards had one or two other solder issues.
The second board had still had issues after fixing the above. Despite seeing the problem quickly, it took me a while to figure out what was causing the issue. The problem was that the current sense voltage remained lower than the input to the IC. They should be the same. Something was causing that voltage to go up. I replaced the two diodes, checked all of the resistor's values, replaced the 0.01uF capacitor, replaced the IC and replaced the 14 pin socket. I rewound the transformer. During the course of the tests I occasionally cleaned the board. I noticed that the input to the IC's voltage was changing. This was weird. I looked at the schematic and the input pin's trace runs right next to the 12 volt trace. I scraped between the two traces and cleaned the board again. The issue was improved but will require some more cleaning to get the DCCOD to full operation. What was happening is the flux was acting like a resistor between the two leads
I suppose the real question is what type of solder are you using? The flux is conductive and is causing problems with the DCCOD's sensitive circuitry.
Suggestions for fixing the boards,
-Make sure each joint is soldered. Look at each join from multiple angles as the issue that I found was one side was soldered and the other side was not.
-Make sure there are no solder bridges.
-Make sure that there aren't any clipped pin as both of the boards had,
-Clean the flux off of the board, especially the area between the two traces that go to pins 4 and 5 on the IC. This turned out to be the critical point in the one circuit.
Also note that the windings are a loose on the transformer. You'll see the tight windings one the one that I rewound. You will get better performance with tight windings than loose ones.
Regards,
-Marc Robertson
SLIQ Electronics
Again, thanks to Marc for his help and fantastic customer service!
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Edited by - LVRALPH on 07/04/2012 04:43:13 AM |
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LVRALPH
Fireman
5431 Posts |
Posted - 07/05/2012 : 05:22:56 AM
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Well, I still have two DCCOD's that I did not send to Marc for repair that do not work. So, I had at them. I could find no component issures. I re inspected the solder joints again. I found two that could be questionable so I resoldered them to make them pretty. I tested both units and still the same. The LED stays on no matter what the pot setting. This was after re cleaning the board again.
I can still see the flux residue remaining, so I tried this. I took a small flat screwfriver and carefully scraped between all the traces on the board. Marc, was saying that my flux residue was conducting, so I tried this. After a short time of using this to clean the board I tested them. BOTH BOARDS WORKED. So this is my major problem. I am going to switch to my RS rosin flux, and will clean them after much more thoroughly.
I had about 2 hours free time before company arrived, so I went about installing them. I had previously ran two sub busses for OS 121E and OS 121W. I finished insulating the gaps and reattached the feeders and ran new ones for each OS. I then connected the input wires from pins 5 and 6 to the DCCOD's.
Block 121E works perfectly and reports upstairs that the block is occuped. (Pin 5) However, block 121W (pin 6), while detecting, is not reporting to the system upstairs, even though the LED lights on the detector when an engine enters the block. I'm not sure what is going on, so I will have to investigate.
I will not have any time today or tomorrow to work on this after work. It will be straight to Lake DeBlasi with its warm water during the 98 to 100 air temps. Bit the weekend is looking good, as the lawn will not need cutting due to the high heat.
I'm really starting to feel the pressure now as Bill is requesting lodging info for his anticipated visit. This along with my friend Mark making clock sounds...you get the picture. Can you see me sweating a little.
One thing i am thinking of doing is having a few people over from my Friday night group to help test the RR. I have ripped so much out and re-installed so much, I really need to run the entire RR during op session conditions to find out the major bugs. I would do that over a couple evenings then restage for the Aug session. Hold on to your hats folks, this is going to be close. |
Edited by - LVRALPH on 07/05/2012 05:34:00 AM |
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MarkF
Engineer
USA
9276 Posts |
Posted - 07/05/2012 : 2:17:41 PM
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...tick...tick...tick...
You know, I don't have a pool. I stay cool by hanging out in my basement and getting stuff done![:-censored]
No more excuses! |
Mark
See my homepage at http://home.comcast.net/~prrndiv/
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LVRALPH
Fireman
5431 Posts |
Posted - 07/05/2012 : 7:31:49 PM
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Mark, who you kidding. When you had your pool you used it and got nothing done on the RR.
After a long swim I had just enough energy to build another DCCOD. This time I switched to my RS rosin flux and it came off much better with the flux remover. I then took the board out to the sink in our garage and scrubbed the heck out of it under hot water. Taking it out to the sunlight the board shines with little trace of flux. I am letting it air dry until tomorrow, then I will insert the IC chip. Saturday i will test the puppy. |
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jbvb
Fireman
USA
1866 Posts |
Posted - 07/05/2012 : 9:24:20 PM
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| Good luck wishes from up north! |
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LVRALPH
Fireman
5431 Posts |
Posted - 07/06/2012 : 7:33:51 PM
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I built a detector last night and ione tonight. I fully expect these to work when I power them up tomorrow. But, first I built the last DCCOD mother board to hold them at the Packerton node. I ordered 6 more DCCOD's as I think I am thre short of what is needed.
Tomorrow I should be able to kicjk some model RR butt. I'm taking off from the gym, and should be downstairs by 6:30. I fully expect to get 12 hours into the project. Lets see what happens. Of course with it going to be 101 tomorrow a swim is in the works. |
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LVRALPH
Fireman
5431 Posts |
Posted - 07/07/2012 : 7:05:12 PM
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Today was a good day. I spent 9 hours in the basement. It would have bee 11, but the pool called my name.
I built 4 DCCOD's today and installed them and the two I built Thurs and Fri.
The time consuming thing I did was to rip out the bus wire between Packerton and Hetchel on both mainline tracks. I then managed to re install the buss for # 1 track. I then ran a bus wire for OS 119 W which ran from Packerton to Lehighton. Two more bus runs were installed. The short one from Packerton to OS 122 (Packerton Yard Lead) and OS 125 (CNJ interchange at Hetchel) All the feeders were installed except for OS 125.
I hope to have at least 6 more hours at this tomorrow. I am hoping to have the entire mainline powered by the end of the weekend. |
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plavallee
New Hire
Canada
8 Posts |
Posted - 07/07/2012 : 7:17:43 PM
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"but the pool called my name"
Do any other lawn and garden features talk to you? If so,please take a break.
Great work as always. I will have to get to Jersey to checkout this wonderful layout.
Patrick Lavallee
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Some say"blind obedience".
I say "malicious compliance". |
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MarkF
Engineer
USA
9276 Posts |
Posted - 07/07/2012 : 7:47:46 PM
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| Ralph hears voices all the time, but those of us who know him have learned to live with this and humor him! |
Mark
See my homepage at http://home.comcast.net/~prrndiv/
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LVRALPH
Fireman
5431 Posts |
Posted - 07/08/2012 : 06:00:29 AM
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quote:
Originally posted by plavallee
"but the pool called my name"
Do any other lawn and garden features talk to you? If so,please take a break.
Great work as always. I will have to get to Jersey to checkout this wonderful layout.
Patrick Lavallee
Yes, the lawn mower says " leave me alone", but my wife makes me ignore it. As for the voices, I am OK unless I listen to the guy that says climb the high water tower. :)
I hope to put in 6 hours of work today. |
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vzjtothalo
Section Hand
USA
90 Posts |
Posted - 07/08/2012 : 08:19:38 AM
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Ralph:
My trick for soldering cleanup (especially components built at a bench) is to wash in the infamous soapy water and air-can dry. Also you can try 99% alcohol spray. Your friendly neighborhood Verizon FiOS guy would have the latter.
John |
John Loesch
For God so loved the world, he did not send a committee.... |
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LVRALPH
Fireman
5431 Posts |
Posted - 07/09/2012 : 05:07:25 AM
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Thanks guys for the help and encouragement. I am feeling much better after this weekends 14 hour effort about holding the August session.
The entire mainline now has all its new sub busses installed and they are connected to the CMRI system. I can run an engine (not a train yet) from NY Division staging to Coxton Yard. Only the two sub busses for the Coxton crossover remain to be installed and one detector needs to be built for OS 122. I feel a whole lot better.
Now, I can focus on getting the turnouts to work, which would put the RR back in operation. Still to be installed are the turnouts at OS 121 (Packerton crossover,) the electric lock at turnout 120 (Crossover to enter/exit Packerton yard), OS 122 (turnout to enter/exit Packerton yard via yard lead), and both turnouts at OS 125 (Hetchel). I also need to pull down and re install two turnouts for sidings at northampton, as they have their old DS 54 wiring.
Still to troubleshoot are why the turnout at Laurel Run (OS 164) has stopped working. This one is critical. Also, why the turnouts for OS 132, and OS 175 are not working. Turnouts 164 an 132 where working, so this is concerning, but maybe it is nothing big.
I also need to string a main buss to the east end of the layout to power the sidings, hook up the yard turnouts to the CMRI supply and reconnect some yard turnouts that suffered a Ralphie whoops moment.
At that point, I just need to clean the layout, then test everything to see if it works. I am thinking of inviting a few of my buds over on Friday July 27th, to have a dress rehersal op session. We might not run the whole schedule, but enough of the trackwork to let me know if there are any issures.
The one thing which looks in doubt, but I won't rule out is building and installing a DOUT 32 card for the machine upstairs. This output card provides most of the block indicator lamps for the east end of the RR on the CTC machine. Not only must I build it, and hope it works, but I need to connect each lamp to the machine. No small task.
So, as I type this I think the odds are 75% I might pull this off. One wildcard is things are very slow at work in August, and I most likely have some unpaid days off early in the month to work on this. So hold on to your hats. |
Edited by - LVRALPH on 07/09/2012 05:17:27 AM |
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Steam Nut
Fireman
USA
1277 Posts |
Posted - 07/09/2012 : 07:01:47 AM
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| Tick,Tick,Tick! |
Steam Lives! |
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LVRALPH
Fireman
5431 Posts |
Posted - 07/09/2012 : 07:24:00 AM
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quote:
Originally posted by Steam Nut
Tick,Tick,Tick!
Some one say something? |
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MarkF
Engineer
USA
9276 Posts |
Posted - 07/09/2012 : 08:28:48 AM
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quote:
Originally posted by LVRALPH
quote:
Originally posted by Steam Nut
Tick,Tick,Tick!
Some one say something?
Yes, that was another crew member saying "tick...tick...tick" |
Mark
See my homepage at http://home.comcast.net/~prrndiv/
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Signaling my model railroad
