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Author Topic: Help wanted, Small Co/freelance Near Macclesfield, Manchester UK  (Read 2137 times)

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Offline WheatElec

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Help wanted, Small Co/freelance Near Macclesfield, Manchester UK
« on: February 14, 2017, 10:52:15 PM »
Hi

I am an electrician that happens to work on a few outdated & obsolete machines in the South Manchester, UK area. I am great at fixing control panels and I even fix some PCBs however I do not have enough time or knowledge to fix everything.

I would like to make contact with a small company / freelance electronics engineer that I can refer to/ give work to as needed. Preferably near to me. Can you help?

Generally I get called into work on a temperamental/failed machine. All the electrical engineering side I can fix. But where the wires turn into PCB traces I struggle, I just don't have the knowledge, or enough time to cram it into my head fast enough to solve the problem. Times I have identified a fault as relating to the PCB I refer it back to my customer, they then find a few companies to pass it onto for repair. Unfortunately most of them don't even promise to look at the board for 2-4 weeks. So the PCB ends up back on my lap. As I tend to fix what ever gets thrown at me, I battle my way through to repair it. Essentially what might take me 3-7 days to repair may only take an electronics engineer with a proper scope & knowledge a few hours. but my 3-7 days is still much better than it being sat on a shelf for 2 weeks. Its mostly through hole stuff from the 90's.

If you think you could help, and are relatively near by I would like to hear from you. I have so far worked on Print controllers, CNC's, Plotters, High Voltage power supplies. Pretty much everything I get to fix is obsolete & has no documentation. And despite me enjoying the occasional PCB repair challenge. In am much much better with a control panel full of wires! If this sounds like something you can help me with please get in touch! [email protected]

Thanks

Richard


Few examples of the type of stuff..

Ahh, and just as I am about to click send I have had a phone call about the machine with the above board in. Which may be at fault again. replaced a few unhappy Tantelums on it last year.

« Last Edit: February 14, 2017, 10:54:15 PM by WheatElec »
 

Online Ian.M

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Re: Help wanted, Small Co/freelance Near Macclesfield, Manchester UK
« Reply #1 on: February 14, 2017, 11:52:39 PM »
I've been on the repair shop end of this game.  Unfortunately there's not a lot one can do cold checking this sort of board unless there is obvious damage or parts that are generally suspect with age, so all one can fix is the low hanging fruit.  To do a better job one needs documentation and a test jig, or access to the whole machine + someone who actually knows what normal operation looks like in detail.  Building a test jig isn't cost effective unless you are going to specialise in repairing a particular board, so IMHO you should be looking to recruit a part-timer or subcontractor with component level repair experience from before everything went SMD, who is willing to come on-site with you and also do bench work at your base.  Its probably a good fit for a retired TV repair shop tech with time on their hands.
 

Offline artag

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Re: Help wanted, Small Co/freelance Near Macclesfield, Manchester UK
« Reply #2 on: February 14, 2017, 11:57:25 PM »
I agree with Ian. If I repaired something like this, how would I be able to test it before returning it ?
 

Offline WheatElec

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Re: Help wanted, Small Co/freelance Near Macclesfield, Manchester UK
« Reply #3 on: February 16, 2017, 04:56:51 AM »
Thanks for the advice.

I thought I might get a reply something along those lines, but then you don't know if you don't ask!
I took the plunge and got a proper scope, well a Rigol DS1054. I've been pondering about it for a while mainly for hobby use, but occasional work use. Now seems as good a time as any. Hopefully by the time I've sorted this thing I'll have learnt to properly use most of it as well. My fluke Power Quality analyser has a 20Mhz scope function built in, but it's Auto everything so it's been great for tracing trough clear and easy signals to follow, or electrical fault diagnosis (why I bought it) but it's a bit rubbish for this.

Anyway, thanks very much, and my request still stands, as today I would have preferred working with my apprentice, rather than stuck in a dingy cupboard with this old machine! No leg or elbow room.

Cheers

Richard
 

Offline paulcav

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Re: Help wanted, Small Co/freelance Near Macclesfield, Manchester UK
« Reply #4 on: March 01, 2017, 05:49:09 AM »
had a look on google for "intlas scheda" and it found nothing relevant.

So even if you could find an engineer it would be difficult to fault find without a circuit diagram. Then the engineer would have to reverse engineer the whole system which would take time. Another possibility would be to replace the board with a modern equivalent that would do the same job.


Edit:
found some Italian site that maybe the company

http://www.tpaspa.it/controlli-numerici-e-plc.html


well the logo on the one of the pics is the same on the website

tpa Spa
Technologies and Products for Automation

it needs a login name to access the support section. Or you could give them a call ... so how is your italian?  :)
« Last Edit: March 01, 2017, 06:27:31 AM by paulcav »
 
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Offline tpowell1830

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Re: Help wanted, Small Co/freelance Near Macclesfield, Manchester UK
« Reply #5 on: March 01, 2017, 06:11:53 AM »
My brother had a machine shop that had old equipment, CNC etc. and he called on me every time he had problems with his machines. As was said, I picked the low hanging fruit and looked for obvious items such as bulging caps, obvious hot spots and bad traces, and, even though he had complete schematics for these, it is extremely difficult and time consuming to troubleshoot to the extent that you could look at a signal on a scope and infer any problems or issues.
The analog portions were doable with a scope, providing you had docs or clear views of traces so as to reverse engineer a circuit, but even that was sketchy and time consuming. What I did find out was that this brand of machines were still being used, even though they were obsolete to the manufacturer, but some companies had started in the sole purpose of repairing the boards for these machines. This company had rebuilt and tested boards that you could swap out with them, but it was not very cheap, but what is cheap? Your time spent for all those many hours analyzing and troubleshooting is worth something. An indexing control board, for instance, rebuilt, was $600 and well worth it if you needed it. Ten hours of downtime on this machine was worth -$1200, due to loss of production.
PEACE===>T
 

Offline WheatElec

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Re: Help wanted, Small Co/freelance Near Macclesfield, Manchester UK
« Reply #6 on: March 03, 2017, 03:52:43 AM »
Thanks for the Replies!

Well done for finding the Tpa website. It took me a little while to find it myself a few months back. but alas, they were no help.
Unfortunately my Italian is rubbish. Which considering I have been repairing a lot of Italian textile machines for the last few years it would be good if it was better. Thank goodness for data-sims and google translate is all i can say!

Since I posted my original plea, my customer got hold of the internals of another machine that was about to be scrapped, so I got a few large boxes to go through the other day. I've not made a full assessment, but I think I have all the main control cards & two of the main interface boards (top picture). They are an older revision, there is less filtering on the incoming power supply side. and a couple of other changes. Good news though, It worked!

Prior to these parts, I was coming to the conclusion though prodding and poking around with my scopes and a bunch of data sheets that I think the problem is around the encoder and positioning data in relation to the information coming in (vague yes, as I said Im better with wires!). With putting the replacement board in a few of these symptoms have disappeared for a while, but It has stopped mid run after working flawlessly for a few days. So, I shall be going though my doggy bag of spares to see what changes, and fixing the "low hanging fruit" on the original board if I get time.

 For now, I have been putting a bit of effort into another cranky old machine, which is more up my street, that I can buy and configure modern parts for.

Richard


 

Offline tpowell1830

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Re: Help wanted, Small Co/freelance Near Macclesfield, Manchester UK
« Reply #7 on: March 03, 2017, 05:07:59 AM »
Thanks for the Replies!

Well done for finding the Tpa website. It took me a little while to find it myself a few months back. but alas, they were no help.
Unfortunately my Italian is rubbish. Which considering I have been repairing a lot of Italian textile machines for the last few years it would be good if it was better. Thank goodness for data-sims and google translate is all i can say!

Since I posted my original plea, my customer got hold of the internals of another machine that was about to be scrapped, so I got a few large boxes to go through the other day. I've not made a full assessment, but I think I have all the main control cards & two of the main interface boards (top picture). They are an older revision, there is less filtering on the incoming power supply side. and a couple of other changes. Good news though, It worked!

Prior to these parts, I was coming to the conclusion though prodding and poking around with my scopes and a bunch of data sheets that I think the problem is around the encoder and positioning data in relation to the information coming in (vague yes, as I said Im better with wires!). With putting the replacement board in a few of these symptoms have disappeared for a while, but It has stopped mid run after working flawlessly for a few days. So, I shall be going though my doggy bag of spares to see what changes, and fixing the "low hanging fruit" on the original board if I get time.

 For now, I have been putting a bit of effort into another cranky old machine, which is more up my street, that I can buy and configure modern parts for.

Richard

Sometimes the positioning board updates also require the encoder to be updated to more lines per revolution. This can cause considerable problems if not known.
PEACE===>T
 

Offline danmcb

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Re: Help wanted, Small Co/freelance Near Macclesfield, Manchester UK
« Reply #8 on: April 20, 2017, 06:49:41 PM »
I just saw this. And FWIW my 0.02 ...

I do a fair bit of repair of old gear, with or without documentation. Generally I get somewhere, though once in a while I do turn a job away as "beyond economic repair".

The key thing to remember is this : It worked until recently.

That means that you can say with a pretty high degree of probability that nothing fancy (like a complex uP chip) has failed. I won't say never, but - almost. On a piece of gear that has worked well for a long time, the things that are more likely to cause issues are:

1. corroded or oxidised or simply loose connections. Use Caig DeOxit spray to clean switches and pots. Be suspicious of any connection which is not gold plated - oxidisation can easily build up a few hundred ohms of resistance over the years, and at a certain moment weird things happen. The best indicator is that things fail intermittently when you touch wiring looms or connectors. Molex crimps can be an issue too, but that normally shows up in the first year or two.

2. dried out electrolytic caps. Usually this only is an issue that happens in gear that runs warm. Sometimes you can see (discoloured, bulging) sometimes not. An in-circuit ESR tester is really useful here. The Peak ESR60 is good. Add to that tantalum bead caps. They are bad news as they tend to fail short-circuit, which can cause big probs of course. They used to be used a lot, even for supply decoupling - if one goes, change the lot, usually you can use good quality electrolytics with no problems.

3. anything that runs hot can eventually fail. Power transistors etc. Again you can usually see. Make sure that heatsink compound is not dried out as well - which can cause overheating.

4. optical sensors that are just dirty or dusty.

5. always asking the customer very carefully if anything specific happened before the failure that could be related. Changes to the installation wiring? a connected piece of gear? did it get moved or jarred? someone decided to hoover out the inside? you'd be surprised. And people don't always tell you. I know it sounds obvious but ...

I do agree with the above posters that it is going to be hard to fix these boards away from the gear they belong in, simply because of not knowing what *should* happen.

hope that helps. good luck.
« Last Edit: April 20, 2017, 06:53:02 PM by danmcb »
 


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