sick GT2Q thermal shutdown on my LM317

hello all
Fixing my GT2Q (neve clone)
I have replace the entire power supply with a new JLM (old transformer was cooked).  Left channel sounds great and loads the 24V rail appropriately (LM317 is warm).  When i have the right channel powered the rail to the right side drops to 7V  and the LM317 gets rocket hot and then thermal shutdown.  what should i be looking for in the circuit?  short to ground?  thats all i can think of.  any help  (btw both 24 and 48 v 317's are heatsinked)

> drops to 7V

Zener voltage. Maybe transistor C and E leads swapped.

More generally... any two point which should be 23V and 3V, but are both 7V.

Since you have a working channel, simple comparison will give a clue.

transistors in the psu all check out and the neve circuit is factory from aurora audio (phoenix back then)  since it worked at one time that rules out pin swap.  ill have to go to the component level to see whats wrong but thanks for the ideas.

What is the current draw of the good channel?

What is the current drawn of the bad channel?

I am going to guess the bad is at 1.5 or so amps(reg limit) and you have a failed device.  What neve circuit is the GT2Q based on?  This will give hints as to were you might have a low resistance path to ground with a shorted device.

If you have a large current draw often the series current path to ground will have low value resistors.  Resistors tend to fail open and sometime power devices fail as a short.

  I would check the power devices for a short.

  Does the unit have tants across the  power supply?  If so use a meter set to ohms and check across the power supply (unit powered down and no voltage left in the circuits).  If a shorted tant across the supply you need to remove them one by one until you find the one(s) that are bad because they are in parallel. 

thanks gus
no tants across the power supply (jlm audio acdc)
sounds like a transistor failing as a short is the most likely culprit pulling additional amps and cooking the regulator.  im going to explore the differences between channels and report back.

thanks
jason

I meant tants across the supply in the gt2q circuit