Mega controlling scoreboard leds @ 12v

Scoreboard works well on breadboard to control 6x7seg mini leds to show scores legs etc.
But working with 2N2222A Transistors to power all led strips with 12v common cathode. All lights up good but arduino mega gets so hot. I put 220 ohm resistors from 74h595 registers to drive the gates at the transistor with 2.5V . But it's still getting hot. This is after tying the arduino gnd with the 12v gnd.
Can anyone help?
I can send visuals if you need further info.
But I am at a standstill.
One extra note..... 6v into the arduino is not enough to run mega with the large Leds but 9v will run it with only half the leds lit. P1 & p2 scores are run on 2 separate pcbs.

We really need a diagram to understand this well enough to help. Just draw by hand and cellphone photo probably OK…

Large scoreboard digits can be done with TPIC6x595 chips.
The TPIC6xxxx is the same as a common 74HC595 shift register, but with integrated mosfet drivers.
Search for TPIC6B595 on ebay.

Sparkfun has the TPIC6C596 version on a breakout board.

Code/diagram included on that page.

Boards can be daisy-chained to as many digits as you like.

The 74hc595 is working fine on the breadboard version
Firing on all six.
It's more of a problem when the gnds from 12v and Mega are joined.

As terryking228 already mentioned, we need to see a diagram.

What is getting hot on the Mega.
The main chip, or the voltage regulator.
Did you use the right base resistors for your 2N2222.
This all could be solved much quicker if you post a diagram.

I sent Terry king the diagram and photos.
Don’t see a way to add them here.
Found it.

I sent Terry king the diagram and photos.
Via msg
Jpg too large to send here

Yes voltage regulator gets hot.

Then you may be drawing too much current from the 5V pin. But we have no idea what you've
connected to that pin - diagram please...

I will post when I can get the image to a size that will send ie kbyte not mbyte

Whatto1, I have to agree with Wawa.

I've built a scoreboard circuit using a TPIC6B595 for each digit. I also only needed an UNO as it essentially runs on a few pins. The advantage is that all the current is dealt with in these registers rather than your Arduino which is much safer. You essentially daisy chain these and send out a signal from the processor with all the numbers. There's quite a few sketches available on how to write these up.