ARC SD135 will not turn on -- fearing the worst

Yesterday my Audio Research SD135 power amp failed. I turned it on, and the amber protect light quickly turned to green---and then winked out. Then, nothing. Replacing the fuse changes nothing. I have an old ARC D130 that I was able to swap in; it and the rest of my system are working fine.

I sent an email to Audio Research service.  Actually, I replied to a previous note from them about the service they were performing on this same amplifier.  A few years ago, they replaced a bunch of parts and sent it back, and the amp has seen only light use since then.  In his note, Kalvin mentioned problems with the ThermalTrak transistors.  I noticed a recent thread that claims these parts are no longer being made.  And Kalvin has retired.  I hope ARC can do something for me.  Any suggestions?

By the way, my power amp is fed by an ARC LS 27, and the speakers are Vandersteen Treo.

Regarding ARC's product suggestions to me, has anyone compared the SD135 with its class-D successor, the DS225?  

I'm not sure about the class-D.  But the DS225 has a lot more power supply energy storage going for it, and no overall negative feedback, according to

I'm also interested in Nakamichi Stasis amps, although I haven't seen any comments about their use with Vandersteen speakers.


But the DS225 has a lot more power supply energy storage going for it
But notice that the manual for the DS225 lists "OUTPUT CURRENT: 15 amps peak at protective shutdown."

The manual for the SD135: "OUTPUT CURRENT: 60 Amps peak (1 millisecond)"

Not what I expected, give the power supply in the DS225.
The DS. is class D
Ayre used the On semiconductor ThermalTrac devices, giive themm a call they may have an opinion on new part number...BTW the thermal trac in my Ayre failed also....