Announcement

Collapse
No announcement yet.

330 a b/p HF Problem

Collapse
X
  • Filter
  • Time
  • Show
Clear All
new posts

  • #16


    Same idea but looks older to me. Also noticed the diagram for the first time when I grabbed that pic:

    Attached Files

    Comment


    • #17
      There's probably another diagram on the inside of the lid there. Wayne will know what it says. To me, it looks like someone spilled their bowl of ramen noodles.

      Comment


      • #18
        Ahhh--what a difference the right diagram makes! There is a fuse in the HF circuit in that model, but not in the other (models') diagrams I looked at. Without a manual and pictures of physical layout, I can't tell you where the fuse is but if you look at the schematic, upper left, right where the power lines come in to the main transformer, there is a switch S1 (the POWER switch), with three wipers tied together with a dotted line. The later models only had a 2-wiper power switch, and only one fuse there. You are looking for the fuse on the right (looks like F1) in the schematic diagram. So, you could have a blown fuse, a bad connection, or that portion of the POWER switch could be bad. Locate and check the fuse, and then ohm out the POWER switch if that's not it. I'm betting on the power switch being flaky--and the fuse may have blown due to current surges as it flaked in and out. Also, if the fuse looks OK, you still need to check it with an ohmmeter. I have found a number of very old fuses over the years that looked good but were not when checked with an ohmmeter--I think the end of the fuse element must get internally disconnected from the end caps somehow due to age and vibration. Never bothered (or had time) to take one apart to see what happened.

        And, as I continue looking at the diagram, there is something really strange. It appears that for whatever reason, they have placed the fan motor in series with the HF transformer primary. Does the fan work? It looks like a bad fan could shut down the HF. Not something I would have expected. Ya gotta love sleuthing through these old monsters! I have to wonder if there is a mistake in this diagram, though. Seems the fan would only run while HF is active, and no other time, which just seems wrong. If I were guessing, I'd guess the fan is NOT supposed to be in series with the HF transformer, and there should be a connection dot on the diagram where the line that runs to the right from the top of the fan motor crosses the line coming down out of the left fuse (looks like F2). That would make a whole lot more sense.

        Ryan, don't tell Helga I called her a monster--I know how sensitive she is about her weight!
        Last edited by Aeronca41; 06-03-2019, 06:33 AM.

        Comment


        • #19
          Well after an unreasonable amount of searching, I finally found the fuse (more or less exactly opposite of the switches/HF in the back bottom of the machine) and sure enough, that one is blown. This was my first time taking that side panel off, and it’s waaay dirtier than the other side. There’s a fine dust that appears to be rubber, coating pretty much everything including the fuse holders. My hope is that’s what the problem was... I shop vac’d/blew everything out with compressed air & wiped it down the best I could. I’ll grab a fuse tomorrow and hopefully be up & running.

          On the fan circuit- the fan has run throughout this process, and still runs with the fuse removed, so it definitely doesn’t seem to get power from the same place.

          Comment


          • #20
            Good find! I think the fan thing is just a mistake on the diagram as I said last night. Everyone makes a mistake now and then. Hope it doesn’t just blow the fuse again.

            Comment


            • #21
              Don't use a typical slow-blow fuse from the hardware store. It should be a yellow in color fuse. I bought a new old stock box on eBay a few ago. It was from the 70s I think. I have four or six spares. These fuses were hard for me to find. I'm not an electro-technico-super genius like Wayne, so I have no idea where to look for such a creature, but I got lucky on fleabay.

              Comment


              • #22
                Hah-- I'm no techno-genius--just an old guy who's been through the school of hard knocks (and a few zaps--those ones from HF in radars are nasty!) over a lot of years. I'd like to know more about those fuses--I only know of regular (fast) blow and slo-blo. What are these yellow ones? Are they glass or ceramic? Please post a pic of the fuse and the box if you can.

                Comment


                • #23
                  I'll try and remember to take a picture. They are fast blow, comprised of glass, metal and probably ceramic. And they came in the original box like you used to see on the shelf at the old school hardware stores.

                  This is my highest level of electronics repair...on my own at least. It's a 1960-70s(?) radio that adorns a shelf on my shop and is my sole means of entertainment while I'm working...outside of me hurting myself of course. Got her back up and running.
                  Attached Files

                  Comment


                  • #24
                    That's a nice-looking old timer. You must know something about electronics if you got it running. And it's far better entertainment than the business end of a plasma cutter!

                    Comment


                    • #25
                      Gave me a good zap when I was testing it too. Guess I was touching something I wasn't supposed to and then touched the radio chassis. Felt like 60hz at least. Ya see, back in the days of this radio, the manufacturer didn't expect a ding dong like me to be sticking his grubby mitts in there and fiddling around, so there aren't warning signs every half inch. The only thing I couldn't get working was the light. I also didn't try to get the light working. It's not just a light bulb though and I wasn't interested in messing with it.

                      Comment


                      • #26
                        Found 'em!
                        Attached Files

                        Comment


                        • #27
                          Check 'em out.
                          Attached Files

                          Comment


                          • #28
                            Thank you! Now I get it. I have some of those. I was thinking of the little tubular glass or ceramic fuses like you see in an old car or old electronics equipment with the plastic cap fuseholder. I should have known those would lack the robustness needed for a machine like Helga! Those are hard to come by; most of the screw-in fuses still available have different ceramic base sizes for different amperages that fit into Edison-base adapters that have to be screwed into home fuseboxes. The goal was to prevent people from putting a 30 amp fuse (or a penny) in place of a 15-amp fuse and burning down their houses.

                            Jmcghee, if you can't find the ones like Ryan has, you can get the adapters at an electrical supply house and then the "new" ceramic base fuses will work. I assume you are not a purist trying to retain "antique value" on your welder--once installed, those adapters cannot be removed without destroying the socket. Just be sure you get the adapter for the right amperage fuse.

                            Comment


                            • #29
                              All I could find at my local hardware store was the slow-blow type for houses. That's not what you want as I understand. I have five extras, so let me know if you can't track one down.

                              Comment


                              • #30
                                This one is a totally different style... it’s the sausage-shaped type that fits into copper “fingers” on either side. I grabbed two (an extra just in case today & will fuss with it tonight. I’ll keep you guys posted.

                                BTW- thanks for everything, this place is great

                                Comment

                                Working...
                                X