Power Pro 256 stuck at 240+ AMPS

First off, I'd like to make it clear I'm very happy with my welder and I would still recommend it to anyone who wants an outrageous bargain. If and when I have an excuse to buy another Everlast welder, I will.

So I was welding today and suddenly blew a hole through what I was working on.

I looked at the welder at it was at 257A. I had it set to 119A.

I tried flipping all the switches and messing around with stuff. The display stays at 257A no matter where I move the AMPS knob, except maybe the first 1/16th of a turn where it will go down to 240A. This is in TIG, PLASMA, and STICK modes.

I had a similar if not identical problem a few years ago and Ray at tech support sent me some parts and I was able to fix it following his instructions. So hopefully its that easy this time.

I called up Ray and he says that the display should be showing more like 400+A if the same chip that died a few years ago died again. Hrmm. I could swear that its doing the same thing it was a couple years ago.

The chip in question is the MC14053BCP on one of the daughter boards, and I believe the rework he had me do before (at my request) was replacing that chip with a socket and a new chip, adding a bypass cap to a resistor nearby, and replacing two diodes. I am an EE so soldering and troubleshooting is easier and quicker for me than packing up the welder and shipping it around. Technically its still under warranty right now, but if I can just replace a couple parts again that would be very preferable because I'm right in the middle of a project.

I just bought 4 MC14053BCP chips on ebay for about 6 bucks. I'm hoping this is the issue. I emailed Ray the control board number and hopefully he may have a few ideas about what I might be able to check to identify the problem if its not this.

Does anyone who has done a 4053 replacement remember the symptoms they had when it died? Did the current stick at full machine rated current or did it go way up to like 400A?

http://i242.photobucket.com/albums/f...psovc4vfvn.jpg

http://i242.photobucket.com/albums/f...pso1zehsoh.jpg

http://i242.photobucket.com/albums/f...psaczotgwt.jpg

Yeah, it would be going to 400 amps if it was that chip. My thoughts might be a bad foot pedal or foot pedal circuit. Have you tried it with the torch switch?

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Originally Posted by performance

Yeah, it would be going to 400 amps if it was that chip. My thoughts might be a bad foot pedal or foot pedal circuit. Have you tried it with the torch switch?

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thanks for the help!!

the display is stuck at 257 without the arc being turned on (no torch or foot switch depressed) Oh wait, so are you saying that the 400AMPs will show up only when the foot/torch switch is activated? Because I'm not checking that, I'm only checking what it says when its just idle. What should the display show when its idle if the 4053 is dead?

Can I just tap the torch/foot switch without letting the arc start (just pre flow) to see if the 400 shows up? I dont want to send 400A to the torch if I can avoid it

A momentary surge won't hurt the torch...only burn up the tungsten. I'd check it with the pedal down. The 4053 could exhibit itself in several different ways IF I remember right, depending on what part of the chip fried.

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Originally Posted by performance

A momentary surge won't hurt the torch...only burn up the tungsten. I'd check it with the pedal down. The 4053 could exhibit itself in several different ways IF I remember right, depending on what part of the chip fried.

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Okay I'll give it a shot.

I was able to find my old email from a couple years ago where I had basically the same problem. Replacing the 4053 and adding the diodes and cap fixed it up until today. So I'm pretty hopeful that will fix it this time. The new 4053's are in the mail and I'll report back once I try them out.

Heres my old email:

"On 3/5/2012 12:32 AM:
Hello,

I had a serious problem with my PowerPro 256 today which makes it unusable. I have had the unit for about a year and a half.

This is not the first time I have used the welder. I have done maybe 120 minutes of welding with it (thats actual current ON time).

I was in DC TIG mode with pulse off, and using the foot pedal, doing simple welding on mild steel with a thin tungsten electrode (close to 1/16" diameter). I had just done a successful weld a few minutes before, and was starting a new weld. Suddenly a huge hole blew in the steel I was welding. I didnt know what had happened. I looked at the electrode and it was gone, it had vaporized about half an inch of the electrode. I looked at the welder and it said 130 amps. I figured somehow I must have set the current too high (I am pretty sure 130 amps would vaporize my electrode). I set the main knob back to 90 amps and tried again. A huge hole blew in the steel again and I let off the current quickly to avoid vaporizing the electrode again. The display on the welder now said 213 amps! A couple seconds later it went back to 90 (the usual delay).

I spent 10 minutes playing with all the knobs, switches, restarting the unit, etc.. but it would always say more than 200 amps once I pressed the footswitch. CUT mode shows between 245 to 257 amps regardless on knob position for amps.

I disconnected the foot switch and tried using the torch button in DC TIG mode again. The display would bounce around and sometimes say -1 or 0666.


"

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Originally Posted by acannell

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I disconnected the foot switch and tried using the torch button in DC TIG mode again. The display would bounce around and sometimes say -1 or 0666.

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Maybe your machine got possessed ;)

Yea,,, I don't like that 666 stuff at ALL.... :D

My 256 did some really weird stuff when the Pedal Connector, on the machine, was not tight. It Maxed-Out as soon as the switch was tripped and acted like I didn't have a pedal connected. Tightening the connector ring and it went back to normal.

There is an 8 pin chip there that can go, but was rare it blew. But check the two signal diodes above the 4053. You have a socket in there so should be a quick thing to test.

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Originally Posted by everlastsupport

There is an 8 pin chip there that can go, but was rare it blew. But check the two signal diodes above the 4053. You have a socket in there so should be a quick thing to test.

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Okay will do. The 4053's should be here Mon or Tue at latest so I'll do everything at once.

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Originally Posted by acannell

Okay will do. The 4053's should be here Mon or Tue at latest so I'll do everything at once.

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The 4053 chips came in today. I replaced it and powered it up. Now the display appears to show the correct current as I move the knob around!

However, I tried welding and vaporized a 1/16" electrode with the amps set to 119A and the pedal pushed down maybe 20%

So I guess that just fixed the display. The display still works after vaporizing the tungsten, so thats good.

Perhaps that 8 pin guy died? The LM358? I may actually have one somewhere...

And I'll check the diodes too.

Any other ideas?

Quote:

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Originally Posted by acannell

The 4053 chips came in today. I replaced it and powered it up. Now the display appears to show the correct current as I move the knob around!

However, I tried welding and vaporized a 1/16" electrode with the amps set to 119A and the pedal pushed down maybe 20%

So I guess that just fixed the display. The display still works after vaporizing the tungsten, so thats good.

Perhaps that 8 pin guy died? The LM358? I may actually have one somewhere...

And I'll check the diodes too.

Any other ideas?

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okay I spoke to soon..

when I was troubleshooting the welder last week I must have left the AC balance knob at 80%..thats what melted the electrode right now I think

so I turned it down to 10-20%, replaced the electrode, and was able to make a good bead on 1/16" aluminum ... yay!

but right after that, I couldnt get an arc started. It just stays in HF making the long thin sparks. I tried it for about 5 minutes (not continuously, maybe 5 seconds at a time) and only once was able to get an arc started. I replaced the collet and used a fresh electrode, no change. I brushed the already very clean aluminum, no change.

This is a problem I've been having for awhile, right up until when the 4053 blew last week. Sometimes I just cant get an arc and then I spend more time in HF, which I think blew the 4053.

Is there a known thing to look at for "hard to start arc"?

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Originally Posted by acannell

okay I spoke to soon..

when I was troubleshooting the welder last week I must have left the AC balance knob at 80%..thats what melted the electrode right now I think

so I turned it down to 10-20%, replaced the electrode, and was able to make a good bead on 1/16" aluminum ... yay!

but right after that, I couldnt get an arc started. It just stays in HF making the long thin sparks. I tried it for about 5 minutes (not continuously, maybe 5 seconds at a time) and only once was able to get an arc started. I replaced the collet and used a fresh electrode, no change. I brushed the already very clean aluminum, no change.

This is a problem I've been having for awhile, right up until when the 4053 blew last week. Sometimes I just cant get an arc and then I spend more time in HF, which I think blew the 4053.

Is there a known thing to look at for "hard to start arc"?

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okay it looks like one of the things that can case hard to start arc issues are points

looks like my welder has the "old style"...very small little deals

its tricky to measure the gap because theres not much room in there but it would appear to be around 20 thou...is that too small?

should I try to clean them or something?

http://i242.photobucket.com/albums/f...psk7qgque2.jpg

Quote:

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Originally Posted by acannell

okay it looks like one of the things that can case hard to start arc issues are points

looks like my welder has the "old style"...very small little deals

its tricky to measure the gap because theres not much room in there but it would appear to be around 20 thou...is that too small?

should I try to clean them or something?

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Try .025-.035 range. I used to have people that had no tools get a credit card loose enough to slide in and out. Let them discharge before each test too, especially if you have a metal gauge.

Some machines liked them tighter, some looser. I always figured the humidity or something, but it would make a difference.

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Originally Posted by everlastsupport

Try .025-.035 range. I used to have people that had no tools get a credit card loose enough to slide in and out. Let them discharge before each test too, especially if you have a metal gauge.

Some machines liked them tighter, some looser. I always figured the humidity or something, but it would make a difference.

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Okay right after I posted yesterday, I wanted to try and get things working. So I sanded that points with 600 grit just enough to where the crud on them was removed. Then I set them to 0.045" because I saw somewhere where that was apparently the value suggested by tech support to someone years and years ago. Didn't work.

So then I just pushed them together with my fingers, not really setting them to any particular gap. And I was able to get good starts and weld for about 30 minutes with plenty of fast restarts!

So I think that things are all good now..hopefully.

I notice that there are two different kinds of "failure to start" symptoms.

1) The HF arc is a long skinny arc and a constant buzz with no flashes. Like watching a continuous mini lightning storm. Thats how mine was acting.

OR

2) You dont even see the HF arc. Instead you get a slower-rate (maybe 3 to 5 times a second versus the zzzzzz of #1) POOF POOF POOF POOF where its like the arc is starting but then immediately going out.
Thats what happens occasionally to me now.


Is #2 "normal" hard-to-start-arc from say dirty aluminum and/or using pure tungsten?

I'm pretty sure #1 only happens because of electrical/points issues.

And, for the future, is there anything else I can do to make the welder a little more reliable or start arcs even better? Replacing the chip once every year is no big deal. Heck even once a month really wouldnt be that big of a deal, it pops right out and a new one pops right in, and they are about $2. But it would be nice to make it so the welder has no issues with arc start ever. Has this issue been fixed somehow?

http://i242.photobucket.com/albums/f...ps0k6iaiyi.jpg

So Far, and I've only had my 256 for a couple of years, anytime I've seen your Scenario #1 I've cured it by finding I had insufficient Path-to-Ground.

Maybe clean-up all those connections too?

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Originally Posted by Blaster

So Far, and I've only had my 256 for a couple of years, anytime I've seen your Scenario #1 I've cured it by finding I had insufficient Path-to-Ground.

Maybe clean-up all those connections too?

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Yes I have seen that too..and it has been the return. Either I forgot to connect it, or its not making a good connection. But I spent a good hour taking apart the ground clamp and brushing everything then tightening it back up, to no avail, at least, thats what was happening before my welder was apparently fixed by chip replacement + points adjustment. So yes #1 causes could be internal welder malfunction or return path problems

Quote:

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Originally Posted by acannell

Yes I have seen that too..and it has been the return. Either I forgot to connect it, or its not making a good connection. But I spent a good hour taking apart the ground clamp and brushing everything then tightening it back up, to no avail, at least, thats what was happening before my welder was apparently fixed by chip replacement + points adjustment. So yes #1 causes could be internal welder malfunction or return path problems

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Some of the old posts will range from .020 (credit card range) and .045 was probably the max. But most worked in the range I posted.
Glad you are getting back running. Lucky the chip was in a socket.

Quote:

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Originally Posted by everlastsupport

Some of the old posts will range from .020 (credit card range) and .045 was probably the max. But most worked in the range I posted.
Glad you are getting back running. Lucky the chip was in a socket.

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Yup, thanks to Ray from a couple years ago lol

So is there anything I can do as far as improvements or upgrades? Are the newer design points better for this issue or are they beefier for some other reason? What about the 4053 circuit? Has it been changed somehow that I can do on mine?

If its just a matter of swapping a chip once every few months I guess that things are good enough. But if the points wear out too much or some other part of the circuit dies then I would like to know if I can improve it all somehow..

Quote:

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Originally Posted by acannell

Yup, thanks to Ray from a couple years ago lol

So is there anything I can do as far as improvements or upgrades? Are the newer design points better for this issue or are they beefier for some other reason? What about the 4053 circuit? Has it been changed somehow that I can do on mine?

If its just a matter of swapping a chip once every few months I guess that things are good enough. But if the points wear out too much or some other part of the circuit dies then I would like to know if I can improve it all somehow..

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There was a choke mod. Do not recall what is was. I can look it up. Ray should know.