Help Lincoln 300/300 wont tig on DC ,weak HF wont light up.

First time posting on this board.Any ideas will be very much appreciated.Bought this Lincoln 300/300 about ten years ago.It stick welds like a champ with no issues but the tig function has been a real pain in the butt since I got it.Bought a new foot pedal torch,etc to get a good start and it initially welded aluminium castings I work on occationally.Problem is its unreliable.I was going to try welding a stainless steel manifold .Set my machine settings to DC-,soft start off,spark sw/start only.30 on argon also set the sets of contact points to .010.Result was a very weak fingery spark that wouldn't weld.This machine does a lot of sitting but is clean and in a dry shop that is heated a lot of the time.I am an amateur welder at best so be gentle.

When you have the 300/300 switched for start only high frequency then you will have high frequency for the preset amount of arc established time before it automatically shuts off the high frequency.
You are using a foot pedal so when you push the pedal to establish welding arc you should have a very good and constant arc jump between the high frequency contact points, with the points adjustment door removed you should see this.
As you have already adjusted the point gap (correct gap is generally on a decal on the access door) I would check the condition of the points them self's, there could be a problem with the relay or the capacitors in the high freq start system, be careful as high freq can be a dangerous shock hazard. If all looks good there then it is also worth mentioning that high freq super imposes the weld current carrying cables so a poor work/ground connection or torch connection could be at fault. hope this helps........

Dana gear,I cleaned the contact points with emery prior to setting them to .010.Since the weak High freq is present in both AC and DC operation it would make sense there is a common thread there.I also turned the remote off and tried to establish an arc on panel settings with the same result.I will trace the circuts back and go over all my grounding and see if it improves any.Thank you for your reply,will repost with what I find .

Have you gone over all your external gear, like your torch leads and etc? I had a problem like this long ago on my 300/300, it turned out that the connector block for the torch was just barely resting against the steel foot of the welder, and when I pressed the pedal the HF would jump from the block to the foot of the welder, and no current got to the workpiece. Drove me batty until I laid all the leads out on the floor, which incidentally pulled the block away from the machine. I also once had a situation where the coil of leads worked like a big electromagnet under AC and sapped a lot of power from the arc. Maybe something arcing or shorting inside the case?

Make sure your stinger for stick welding is disconnected.

Well guys you are not going to believe how simple this turned out to be and how stupid I feel about it.Turns out gbent you almost hit it.In the instructions it tells the operator to disconnect the stinger so you don,t get bit so I did,but I also disconnected the ground lead also,duh.plugged it back in and she lit up like a Christmas tree.

gbent said:

Make sure your stinger for stick welding is disconnected.

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Mud,Thats what is great about this site,we can share all this weird stuff that happens in the shop and hopefully save each other some headaches,and money.Thanks ,I appreciate all you guys insight.