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GI fuse keeps blowing

Ac volts setting.

Put one lead on Brown one lead on white/brown. You should get around 6v ac. If you do then you know brown pair is good

Repeat for the other pairs until you find a pair that measures low volts.

Lets say it’s the yellow pair. So which pin is not working?

You know both brown pins are good. So put one lead on brown, the other on white yellow. If this pin is good you’ll see 6volts. If bad you won’t.

Then put one lead on white brown and the other on yellow. This will tell you whether yellow is good or bad.

You then will identify the single pin that is not in the circuit. Refer to schematics to see where that goes, and move the probe back along the circuit searching for the missing volts maintaining the other probe on a good (opposite polarity) output.
 
Ah I think I have got somewhere no voltage on the bad pair (violet and white & violet) since rewiring the connector. But I have good voltage from the corresponding pins on the female half of the insert board connector. So I’m thinking I have a couple flakey male pins? Which is funny considering the grey gorilla right coil decided to not work today. Which was cured by undoing it a couple times so will prob repin that one to at some point
 
Ha well that didn’t work. So I’m assuming there must be a duff lamp holder in the chain.

How did you come to that conclusion? A short circuit lamp holder would blow a fuse. If you have voltage at one side of the inline connector but not the other then the pins are not contacting. Try closing the female socket up a little with a small screwdriver so that it exerts more pressure on the inserted pin.
 
J105 and J106 are interchangeable so try putting the problem connector on the other feed and see if the problem continues or not. leave the other connector disconnected in case that is causing problems.
 
So I have tried what peter suggested but no change.

I’ve put fresh fuses in.

I’m getting 500 volts on the pair of pins on the female side of the light board loom.

I’ve put new crimps on both sides of the trouble pair.

I’m getting no volts at any of the lamp holder on the bad pair
 
500volts ? I’d go back and remeasure that. Can you show pics of the rewired GI connectors and explain exactly where each probe is when measuring voltages perhaps with a picture.
 
lol 5.00 even

I had 1 probe in the female pin for the violet wire and the other in the one for the white and violet. With the connector done up I then startind from the last connector in the chain put each probe on the contacts for each wire on each holder
 
You should be getting around 6.5v. Carry out comparisons with working circuits. If you measure the 5v on a working circuit then it’s probably just meter problem. But if you get 6.5v in working circuits and 5v on non working one go back and find out where the voltage is lost.
 
Ok so I did some more investigation does seem to be abit of weirdness going on with the voltages.

Violet - white & violet (the problem pair) = Earlier in the night before I decided to write it down it was 6.3 but on second testing it was 7.3v

Green - white & green = 6.6v

Yellow - white & yellow = 5.8v

Brown - white & brown = 7.4v

The above are all taken from the female connector pins
 
I do find it strange how when the main connector was originally wired incorrectly when I put in a fresh fuse all the lights lit up. But now it’s wired as the manual says the voltage can’t even get past the light board connector
 
I do find it strange how when the main connector was originally wired incorrectly when I put in a fresh fuse all the lights lit up. But now it’s wired as the manual says the voltage can’t even get past the light board connector

Not at all, it just means J103 is probably wired incorrectly as well (or there's hidden jumpers on the back of the driver board) which is why you're not getting the correct voltages. Just continuity test each GI string as per the buzz diagrams
http://pinwiki.com/wiki/index.php?title=Williams_WPC#WPC-95_General_Illumination_Problems
 
Thanks Pete I will have ago tomoz I’m pretty useless at electrical fault finding lol.

I do think I have found the fault with the stand up target I mentioned earlier in the thread registering as a trough switch. I think it’s wired the wrong way round (if it’s meant to be the same as the left anyway).

Left
5ec2d697f54d4474644de82f2fc2e69f.jpg

Right
897d98451eaffab9a17289ebc006183c.jpg
 
Correct it's wired wrong, you need to move the white stripe wire to the other end of the diode.
 
well a little progress, I took the board out to do the buz testing from pin wiki and the board appears to be fine all buzzed ok. And there are no hacks on the board all that appears to be done is the 0 ohm jumper mod. I had them all working but it then blew f111 again I believe it is to do with the lamp holders one on the violet line had a broken wire that had one half only lightly pressed into the holder. I reseated it and they all worked on power up for a few mins anyway then the fuse blew again. Would iffy bulbs cause a fuse to blow? There was a lamp out in the violet line so I took it out and rotated it then it worked, same with 3 in the green line. They stayed lit for a few mins then f111 & f110 blew (green and violet line). So to me it looks like something to do with the holders or bulbs
 
So I’ve still not really got to the bottom of this. I replaced and repined the 15 pin connector. All the lights lit for 10 mins then the fuse (f111) blew again. Do you think this is down to something on the board or dodgy sockets?
 
If you remove the pins from the header and let the board run for the same amount of time, it'll either blow or not...

If it doesn't - it's off the board. If it does, it is on the board.
 
Then it is off the board, have you put some new bulbs in, i.e... LED's?

I put some LED's in and there was one that kept taking out a fuse. I would remove each bulb within the string and replace.
 
Then it is off the board, have you put some new bulbs in, i.e... LED's?

I put some LED's in and there was one that kept taking out a fuse. I would remove each bulb within the string and replace.

No all incandescent bulbs and I’ve not touched em they were in it when it turned up. Just about to try something. There’s a ropey looking replacement holder in the suspect chain just changed it see if it will hold
 
A string has what - 10 bulbs in it? Swap them out - but not sure incandescents will act the same as others....

I am kinda lost as to where you got with the diagnosis, do you know which string is causing the issue? I can think of a dirty way of doing it though, that is create two bits of wire with one end wire you can put in the female end, then one end with a croc clip... then check through each string to validate the fuse popping.
 
My diagnosis was the board buz test that Pete posted tested fine. So has to be something the insert board side. Problem strings were violet and the green one. Since I reseated all the holders it’s just the green string
 
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