Electrical help please

Had you brought it in from the cold? seems like something (damp and dirt) caused the tracks to arc and burn then the fuse blew. I would clean the area, change the fuse then clean the track around the damage and apply some solid wire to beef it up. then stand well back and try again.
 
Was just typing pretty much the same thing. Clean it and change the fuse. If you've got an rcd plug as well even better.
 
Probably the transformer gone short then. Unsolder it and check the primary resistance and resistance to ground.

If I was working on an AC at work we'd just order a new board if there was any problem with it. There will be a serial No. On it ?
 
If it's not an inverter type the first thing I would do is put a 230v feed straight to the compressor to see if it starts and runs OK. It's all a waste of time trying to repair/replace the board if what's caused it is a seized up compressor ?

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It looks to me that the area has been damp for a long time causing mold or fuzz to build up on the pcb.
Without having the board in my hands I cant see exactly where the burn is between but it looks like its the rear of the mains input. Is that correct?
If it is its just flashed across between either L and E or N and E. If that is the fact, clean the PCB up with a fibreglass pencil and put a new fuse in and hopefuly you will be OK unless the flash has knackered other components.
 
To add to that, from the photo there looks to be other fuzz on the board around 2 pins on what I guess is the underside of the transformer and other areas, so give it a good brush up before reconnecting
Fuzzy areas highlighted in red that need cleaning. Blue highlighted area has possibly been slightly corroded by damp on surface.
fuzz.JPG
 
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jezport said:
Without having the board in my hands I cant see exactly where the burn is between but it looks like its the rear of the mains input. Is that correct?
Click to expand...
Yes the damage is between the live and neutral next to the input. Main fuse in between.
I'll try running the compressor direct and make sure it's working.
Would a bit of solder on those lines after cleaning do the trick ?
There was a fair bit of dust on the PCB I cleaned some up before photo but I'll do a proper clean up before going any further.

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Figaro said:
Yes the damage is between the live and neutral next to the input. Main fuse in between.
I'll try running the compressor direct and make sure it's working.
Would a bit of solder on those lines after cleaning do the trick ?
There was a fair bit of dust on the PCB I cleaned some up before photo but I'll do a proper clean up before going any further.
Click to expand...

Dont solder it, it needs cleaning. Don't test the compressor unless you have checked the circuit diagram and you know what you are doing. Besides theres no need, put a fuse in after cleaning all the print making sure no carbon is left between the two areas where the 240v has jumped and brush any other fuzz or corrosion off.

Then put new fuse in and test. If it blows again I would remove the mains smoothing capacitor and test once again with new fuse.

After that you will know the board is either good or knackered.
 
BTW you may need to clean the flashed area out quite deep to remove all the carbonized area, but the tracks ant both sides of the area are wide so dont need repair
 
Ok, what should I clean the tracking with, you mentioned a fibreglass pencil ?
Not got one but maybe eBay can assist.
Can the rest be just brushed / vacumed off.
Would PTFE spray help clean ?
 
I've never seen moisture conduct 10 amps blow copper tracks off a pcb. For that to happen there is a low resistance short. Still there's no harm cleaning it up.

The smoothing capacitors smooth the rectified DC on the other side of the transformer, doubt it's anything to do with them.. IMO ?
 
It does look like something was between the L and N on the pcb tracks looking at the pic again mind ? just test the L to N resistance before powering up.
 
Had a similar problem:

Probably caused by damp and a flash over on the pcb.

you will need to scrape out the carbonised PCB section between the two copper (green lacquered) tracks to remove the short.

Can be filled with insulating lacquer/aradlidite.

Any damaged tracks need to be repaired, scrap off the green lacquer and solder copper wire across any breaks or thinned sections.

Ensure pcb is dry and warm and spray with insulating PCB lacquer. (have used the equivalent of wd40 in the past to get the thing away)

Replace the fuses and retire to a safe distance and test.

Good luck.
 
If it was a short-circuit of some part of the circuit, then assuming the fuse did not blow quick enough then you'd expect to see one of the pcb tracks melted / broken, maybe the fuse would then have blown or not.

This does not seem to be the case, rather it looks like a short between the live and neutral tracks which would cause the fuse to blow faster as the current was destroying both tracks.

If it were me I'd clean right round the damaged track area then repair each track by soldering a bit of meaty wire over the damaged section, (making sure to remove the protective coating for about 1cm on the good bit of track you are soldering to), effectively bridging the gap, flood the joint with solder and test again.
 
Richard and Ann said:
I've never seen moisture conduct 10 amps blow copper tracks off a pcb. For that to happen there is a low resistance short. Still there's no harm cleaning it up.

The smoothing capacitors smooth the rectified DC on the other side of the transformer, doubt it's anything to do with them.. IMO ?
Click to expand...
Mains smoothing is across the mains near the input not on the DC side It protects the board from spikes.
Going by the clues that are there of fuzz and watermarks on the board Im going with my diagnosis. There are no tracks blown off the circuit board! It has arched between tracks! Its all there to be seen!
 
Figaro said:
Ok, what should I clean the tracking with, you mentioned a fibreglass pencil ?
Not got one but maybe eBay can assist.
Can the rest be just brushed / vacumed off.
Would PTFE spray help clean ?
Click to expand...
Clean the board, dont put any lubricant on. These are ideal for all sorts of cleaning Scratch brushes and PCB Cleaner spray you could use a pure alcohol like isopropyl but either way make sure its dried before turning on. Use a hair dryer if in a rush
 
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jezport said:
Mains smoothing is across the mains near the input not on the DC side It protects the board from spikes.
Going by the clues that are there of fuzz and watermarks on the board Im going with my diagnosis. There are no tracks blown off the circuit board! It has arched between tracks! Its all there to be seen!
Click to expand...
I think you're you meaning that inductor/choke top left? I've never seen an AC capacitor just put across the mains, it would just waste power charging and discharging with the sine wave.

Smoothing capacitors are for DC. Don't take my word for it though, Google it ?
 
There are a lot of people suggesting all sorts but the facts in plain view for those who understand enough to look at the PCB are.
A. Its arched between tracks. Not blown a component any thing else
B. There are signs of contamination on the PCB which could have been condensation or water ingress (no way to know unless there are further clues in the unit)
C. The fuse has blown

Other than that the rest is guessing.
Without the circuit diagram or having technical knowledge its no use suggesting further testing as you would be just guessing.
 
Figaro said:
There were two pops when I plugged in ... .... eek :eek:
What might cause an overload ?
To be fair I did use a bit of cable laying around and not 2.5mm but it looks ok.
That damage is between the live and neutral with the fuse in between, and both go to the copper coil.
Thanks for help tonyidle , does it look repairable or toast ?
I'll email apuljack tomorrow.
Click to expand...
Cable size wouldn't affect the unit. The copper coil (toroid) has two windings: one passes the live straight through; the other passes the neutral straight through. Neither winding should be in contact with the other. It is a simple suppression device.

I've just taken a detailed look at it. I believe the fault was something shorting the tracks either side of the damage which has now gone. The tracks, despite appearances, will be OK. Replace fuse and try it again. You may wish to clean the damaged area with a little thinners / alcohol / nail varnish remover then cover the patch with clear nail varnish. The PCB function is definitely unaffected by what has happened and I'll be very surprised if there's any collateral damage.

As suggested by others if I'd read right to the end :blusher: .

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tonyidle said:
The PCB function is definitely unaffected by what has happened and I'll be very surprised if there's any collateral damage.
Click to expand...
That's very encouraging, thanks.
I'll order some fuses, clean up a little and report back in a few days (y)
Thanks again to all who helped
 
You mentioned ptfe spray, dont get that anywhere near where you want to solder, its a non stick spray!.
A bit unusual for a track to blow off like that, it would have been caused by excess current perhaps due to poor insulation ie damp between the tracks at that point
Keep your fingers crossed.
I still think it may be a seized compressor or lack of gas, did you follow the compressor resting instructions before switching on? Itll have a good rest, the right way up etc whislt you think about it.
Mike
 
I`ve not used any PTFE on it.
Since last post I just got a soft brush and vacume to remove a build up of dust on the pcb.
I`ve ordered some of those clean up pencils and replacement fuses. When they arrive I`ll clean up the damage and coat with clear lacquer as suggested, fit fuse, reconnect and hope for the best :LOL:
There was no damp apparent, it stood overnight in the garage but not particularly cold.
It was tested and working apparently last month by a motorhome dealer who fitted a new unit for the seller.
I`ve not read any resting instructions in the manual but to be honest it had not been tipped up or overturned in the hours before I tried it.
As you say, fingers crossed
 
tonyidle said:
Cable size wouldn't affect the unit. The copper coil (toroid) has two windings: one passes the live straight through; the other passes the neutral straight through. Neither winding should be in contact with the other. It is a simple suppression device.

I've just taken a detailed look at it. I believe the fault was something shorting the tracks either side of the damage which has now gone. The tracks, despite appearances, will be OK. Replace fuse and try it again. You may wish to clean the damaged area with a little thinners / alcohol / nail varnish remover then cover the patch with clear nail varnish. The PCB function is definitely unaffected by what has happened and I'll be very surprised if there's any collateral damage.

As suggested by others if I'd read right to the end :blusher: .
Click to expand...

The photo does show some pcb track missing, for peace of mind I'd build up the remaining track using wire and solder. Reduced track could result in overheating in that track area and therefore further problems. It would do no harm after all.
 
Sandancers said:
The photo does show some pcb track missing, for peace of mind I'd build up the remaining track using wire and solder. Reduced track could result in overheating in that track area and therefore further problems. It would do no harm after all.
Click to expand...
Fair comment, if all works ok when I clean it up and plug in, I`ll remove it again and see if I can get the track repaired locally as you suggest.

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