Turntable rumbling

Hello Friends, merry xmas
I have at the moment, a Michell Tecodeck turntable, with a Garrot Bros updated P77 cardridge, I have bought new speakers and amp, Redgum amp, with phono stage, and Usher speakers, I have enjoy the "Break in Stage" of all equipment, as It was so much better, but after approx 50 hours use, all of a sudden the LP,s, have a bass boom, at the start of the LP, and any warped LPs is un playable, I took out the styls, from the cartridge, and seems OK.
All My LP's are mimt no clics and pops!!
The last time I played the LP's was on a Well Tempered Classic, an I had no promblem.
I have set the cartridge, on the correct weight, well the Sure was 1gm out compare to the digital, friends I'm geting upset not good after a heart attack!!
Can someone put me on the right track, as I have just got back into Hi Fi, Where I live down here, on the South Coast of Australia, there is no shop, that deals with Hi-Fi, to get any assistance I have to drive 4 Hours to Sydmey!!
Kindest Regards
David Spry
Not to state the obvious but If it was working fine then something changed there. Are all cartridge pins connected? Maybe ground wire on or stereo leads loose from amp to turntable? Have you tried with and without this ground wire connected?
I own a Redgum stand alone phono stage that has worked beautifully for years now. It is on the musical side when paired with the Goldring 1012 (?) cart I have on my MMF-5. I have never expierenced any rumble from this RedGum set up but I use it rarely as a 2nd system. So I doubt that is it but who knows..... It appears from all you have said it is your table, perhaps the bearing needs lubrication beyond that I can't offer any advice.
Maybe the tracking pressure is too high? Rumble is a continuous low frequency rumble sound. What you're describing sounds like it may be something different.
I reread your post. If you're using a Shure M97xe type of cartridge, you may need to set it at around 1.75 grams, if you have the brush/stabilizer in the down position. If you have it in the up position, it appears it should be set at around 1 to 1.25 grams. So maybe your using too little tracking force instead. I would double check the tracking force, and see if it is in the manufacturer's recommended area.

You said 1 gram out, and I'm not sure if you mean off by 1 gram, or set at 1 gram. And, I'm still not sure you are using this type of cartridge. It's hard for me to post an answer if you have a question, due to AudioGon moderators taking extra time to read what I've said. Their friends that sell power cords don't like some of my answers given in the past, causing the extra delay.
Dear Davey,
Is anything interfering with your turntable mechanically i.e. anything different such as heavy speaker cables touching the stand(?) or touching the cable feeds to your phono stage or turntable?

Another possibility is temperature changes from when you first aligned the cart?
If it was done in colder conditions and the cart is now many degrees hotter, your VTA may have become noticeably upset? If you are using a Michell Technoarm then altering VTA may be problematic(??)
Also, Davey, try having a look and seeing if the underside of the cart is "bottoming" on the record as you cue it?
Just a thought...?
Scratch my statement about the Shure cartridge. I'm back on my regular size laptop computer, and can read it better now. Sorry for the Shure brand mistake.
Moonglum is onto something . Evem though your stylus looks great , you may have a catridge suspension issue . The sagging of the cantilever would cause the cartridge body to hit the raised outer lip of the Record .

This " may " be corrected for by raising the VTA [ raise the rear of the tonearm ] .
Ignore my comment about Shure. A friend had me trying an Ipad, or something like that with a small screen. Besides double checking your arm setup, may possibly someone else used your table and dropped the arm causing damage to the cantilever, or suspension? Sometimes they give out, possibly due to a defect. Someone here found out their cleaning person damaged theirs without knowing.

I'm not familiar with your gear, but double check with the dealer to see if the cartridge's compliance is compatible with your arm. Checking all the wires for clearance mentioned above is a good idea too. Maybe someone here may be familiar with it and hopefully chime in.
if its rumble, get a filter?
sounds like a mechanical issue. Start here

1) have you physically changed your setup recently... moved speakers or the TT? If so put them back where they were to see if you were causing yourself feedback or found an unstable TT location.

2) recheck your stylus pressure.. most of what you describe sounds like the pressure is too light. Most cartridges will behave better at 0.3gm heavier than the nominal tracking force recommended. Its always possible something got bumped and the pressure needs recalibration.
hmm above it says you set the TT at 1g m, yet the spec I searched out says the nominal tracking force is 1.8 gm.

Hello Friends
Hoping your Xmas, was good to you!!
My Turntable has no "ground connection", I have been playing my LP's loud latley as Mum has been away!!, this is where I notice the low rumble, from my LP,s.
I have bought a lot of Lps from Americia, with are new and sealed!!, A lot of them are warped, However I had a few in the same codition, when using my Old Well Tempered Classic, as it was a long time ago, I dont rember, the low down rumble!!
I have tried all of the above, including the hot temp and humity at this time of year!!
My cartridge is Garrott Bros P77 update "I think this maybe the promblem??"
I look foward to your advice
Happy New Year
If some one