Transformer fried!

[delarge]

Hi all,
thanks for the advice.

I unplugged the cable on the main board (from transformer) and turned the machine on. This time, the 5 amp fuse blew and the whole machine went off. Would this cancel out a bridge rectifier problem, Mike?

I have compared the primary taps with my Aus. delivered South Park machine (X-Files was a U.S machine) and it looks correct. I don't know why it would develop an issue after having it for around 12 months and working fine?

Also.....when I first turned the machine on and saw smoke (instantly turned it off). Does this mean the transformer for South Park is ready for the bin or will it still be usable as it was only left on for a short while?


Cheers!
Adam.

p.s. will go through all fuses and check their ampages.

[Pinballer]

Ouch mate, not another one!  Hopefully you haven't damaged the one from your South Park. Smoke though, doesn't sound good, I have my fingers crossed for you.  As others have mentioned, you need to check all secondary connections/circuits for a short. Transformers don't just fail, well very very rarely anyway. Your machine has a fault and you need to find and fix it before plugging in anymore transformers.

Hate to say it and it won't make you feel any better, I did give you that advice a couple of weeks ago........

If you do find a replacement, make sure you test the circuits immediately after the transformer for shorts. You don't want to fry the replacment.

Good luck, I feel sorry for you in this situation.

[delarge]

Ouch mate, not another one!  Hopefully you haven't damaged the one from your South Park. Smoke though, doesn't sound good, I have my fingers crossed for you.  As others have mentioned, you need to check all secondary connections/circuits for a short. Transformers don't just fail, well very very rarely anyway. Your machine has a fault and you need to find and fix it before plugging in anymore transformers.

Hate to say it and it won't make you feel any better, I did give you that advice a couple of weeks ago........

If you do find a replacement, make sure you test the circuits immediately after the transformer for shorts. You don't want to fry the replacment.

Good luck, I feel sorry for you in this situation.

Yes, I have myself to blame on this one. Throwing caution to the wind "I'm sure the previous transformer had just gone bad over time. The new one will be fine. There are fuses in place to stop anything bad happening...."

The transformer should work again in South Park, but whether it is safe after this happening and smoke has come out of the transformer for a short period of time?

Once again, another pinball learning experience.

[Boots]

Double check that you have the primary taps set correctly IE: set for 240V and NOT 110V

The mains fuse may not save you in this instance - especially a 5A - I would put a 1A or 2A in with all secondaries disconnected as that should prevent transformer damage.

Would the machine startup at all if the primary taps were set to 110V?
Wouldn't you get other faults aswell?

[Pintoxicated]

I was speaking to Adam today and asked the same thing.  He had a look at the South Park taps and said they were the same.  The SP is an Aussie delivered machine from memory.  The X Files machine had been working fine for some time until the other week when it cooked the first transformer.

Can problems on the secondary side of the transformer cause it to cook and if so, what sort of things?  My first thoughts were that there is an issue on the primary side of the transformer.  It is the bottom section of the transformer that is cooking.

[Homepin]

Can problems on the secondary side of the transformer cause it to cook and if so, what sort of things?  My first thoughts were that there is an issue on the primary side of the transformer.  It is the bottom section of the transformer that is cooking.

In 99.999999999999999999% of cases a transformer (TX) will fry the PRIMARY (mains connected side) if there is an excessive load on the SECONDARY - this is VERY normal.

As this TX is basically directly connected to bridge rectifiers that would be my first port of call unless there is also some sort of surge device (MOV etc) ACROSS the secondary winding? There really is very little else that will cause a catastrophic failure such as this.

The mains fuse IS NOT THERE to save the transformer OR even your game. Its ONLY purpose is to prevent your house from burning down - do NOT ever think the mains fuse will save or protect your game - it won't and isn't designed to - that's why I suggested putting a much lower value mains fuse in with the secondary DISCONNECTED as a test. The lower value is very likely to pop if there is a fault in the TX BUT also it will likely stay intact if the TX is OK but with NO LOAD at all.

[Boots]

As this TX is basically directly connected to bridge rectifiers that would be my first port of call unless there is also some sort of surge device (MOV etc) ACROSS the secondary winding? There really is very little else that will cause a catastrophic failure such as this.

I don't have the schematic for X-Files but looking at Star Wars that came out the same year there is a fuse between the bridges and the transformer, wouldn't they blow if it was overloaded?
The only thing I could find without a fuse was the Backbox fluro, could that be the cause?

[Retropin]

I deal with transformers a lot.. some are better than others.
Mike is correct..MOST transformers will fail on the primary side due to too much draw on the 2ndary. Transformers i deal with have an output of between 6KV and 15KV at 30 or sometimes 60mA. When the primary fails, the transformer cooks rather like what you have there.. winding laminations break down due to heat, transformer shorts and its goodbye primary winding. Ive seen it on the 2ndary also.. this is ugly as the high voltage goes bang and blows a bloody great hole in the transformer lid. Primary failure is very common if its calibrated right to spec or too close.. we always calibrate loading for modern transformers to 80% give or take 5% of open circuit current... go above this and you run them hard... go below and you cause excessive heat... the need for smaller and smaller profiles on these units has seen a decrease in reliability.

All transformers work on the same principals.. i have some transformers on the market that if they run open circuit will burn out pretty quickly... i have others that will happily run open circuit for a couple of years... its all due to the quality of manufacture... some will overheat for no real apparent reason after approx 8 - 10 years of use.. others will last a lifetime.. all down to the quality of manufacture. I know of one Chinese brand that will simply burn out after approx 2 years.. you can almost time your clock to them.
Check your bridges as suggested, but, it could also be that the transformer died ( technical term in my field when explaining to a customer).. it does happen.. not often in a pinball transformer i admit but it is possible.

[delarge]

I deal with transformers a lot.. some are better than others.
Mike is correct..MOST transformers will fail on the primary side due to too much draw on the 2ndary. Transformers i deal with have an output of between 6KV and 15KV at 30 or sometimes 60mA. When the primary fails, the transformer cooks rather like what you have there.. winding laminations break down due to heat, transformer shorts and its goodbye primary winding. Ive seen it on the 2ndary also.. this is ugly as the high voltage goes bang and blows a bloody great hole in the transformer lid. Primary failure is very common if its calibrated right to spec or too close.. we always calibrate loading for modern transformers to 80% give or take 5% of open circuit current... go above this and you run them hard... go below and you cause excessive heat... the need for smaller and smaller profiles on these units has seen a decrease in reliability.

All transformers work on the same principals.. i have some transformers on the market that if they run open circuit will burn out pretty quickly... i have others that will happily run open circuit for a couple of years... its all due to the quality of manufacture... some will overheat for no real apparent reason after approx 8 - 10 years of use.. others will last a lifetime.. all down to the quality of manufacture. I know of one Chinese brand that will simply burn out after approx 2 years.. you can almost time your clock to them.
Check your bridges as suggested, but, it could also be that the transformer died ( technical term in my field when explaining to a customer).. it does happen.. not often in a pinball transformer i admit but it is possible.

I thought it may have been the case when the first transformer was smoking, but after putting the second transformer in and it started smoking instantly, I knew it was something else other than the age of the transformer.

Now this has happened, do you think the transformer is still usable in my South Park machine or if it has started smoking, does that mean it's time to get a new transformer for both machines (when I have X-Files sorted out)?

I am currently trying Mike's fault-finding tips and also looking into the fluoro tube.

Thanks,
Adam.

[Retropin]

Sorry mate.. missed the adding another transformer bit..

Ok... the SP tranny SHOULD be OK so long as it got turned off ASAP... the windings no doubt got hot and the laminations started to cook, but so long as the laminations didnt breakdown - youll be OK.

The flouro tube is just a tube attached to another transformer ( ballast), id be very suprised if its in any way connected to the main transformer.. it should run off the 240V or if its a 110vmachine  , then off the step down. It wont come from the transformer output ( or it shouldnt!).

You have something drawing a lot of current... you need to find what this is and the best way is by a process of elimination. If you go to Jaycar you can buy a trip switch which acts like a fuse except you can reset it... or buy some fuses that are of lower value than those on the output side of the transformer. Plug in the machine with everything on the output unplugged and see what happens.. transformer wont get hot.

Turn off the machine and place a lower value fuse ( say you require 5A.. put in a 3A, if it states 2A then put in a 1A etc.. all fast blow)... plug in ONE connector and see what happens.. etc etc etc until you find just where the fault lies.
Just to add, you can put your finger on the metal plates in the middle of the transformer without danger to see if its getting hot.. or better still, a digital thermometer ( keeps hands out of harms way)

Good luck..

[delarge]

Evening all....I'm back!

Just spent the past half hour working on X-Files.

I noticed a small transformer right up the back of the cabinet that South Park didn't have. A two wire connector coming from the transformer was plugged into this and wires from this transformer fed up into the head. I assume this connects to the fluoro.

Tonight, I unplugged the three connectors coming out of the transformer and the single connector at the front where the power goes in is the only thing connected. I tried a number of different fuses, with various results, but all resulting in a crackling sound and me quickly turning the machine off after around 3 seconds.

1 amp slow blow - fuse blew as soon as I turned the machine on.
3 amp slow blow - fuse didn't blow, but once I heard that familiar crackling sound, turned machine off.
5 amp slow blow - fuse didn't blow, but heard a hum, then crackling sound and turned machine off pronto.

I haven't checked the bridge rectifiers yet, but as nothing is plugged in, I'm guessing that these aren't the cause of the fault. Could the line filter have died?

Cheers!
Adam.

[The pinballist formally known as Dean Morgan]

So the 240v input to the primary side of transformer is still connected? If so transformer is fried most likely.

You could disconnect this input into tranny, if fuse still blows then line filter may be faulty.  But sounds like transformer is stuffed.

Remember, 240v kills, always power off at gpo and unplug to be sure

[delarge]

Yep, still connected on the 240v input to the primary side of the transformer. The three cables on the secondary side are ALL unplugged.

I will disconnect the input into the transformer and test a fuse that way.

Ugh....IF the transformer is stuffed (2nd transformer, two pinball machines now dead), how do I know or fix the machine so it won't blow a third transformer? I was thinking about having a viking funeral for X-Files. Maybe put it on some wheels, set it on fire and then push it down a hill.....haha....I can only laugh at this point.....*wipes tears away*

[Homepin]

I'm amazed you could destroy two TXs this way actually???

My plan to put a 1A fuse in the primary did the trick - with no load on the secondary it shouldn't blow but it did telling us there was an excessive load. You really shouldn't have put larger ones in at this point.

You should use fast blow types for these tests by the way.

There is still going to be an issue with a load on the secondary that has started all of this....................

[GORGAR 1]

Pm sent :-)