I have changed the .47uf bird tird caps, .22uf blue caps, 2 - .001uf blue caps ( basically all caps in primary side of reg circuit) statically check all other reg components but Q 601 an 602 still over heat and die after 45 min. I even tried making heat sinks with no luck there. YES i am using generic C4834's but can get away with it most of the time without thermal probs. Have tried both P's and M versions. any advise or maybe a pws part # if it is still available, Not listed on tritronix model part list. could use the SM if someone wants to Email it to me. thanks much Tony Saracco TCS ELECTRONICS Elgin , IL 60120 847-695-1928 tcselectronics@xxxxxxxxxxxxxxxx ***************************************************************************** Classifieds! Buy or Sell! http://sell.tech-assist.org The Tech Address Book: http://www.tech-assist.org/secure/tip/contact.htm Add a Repair Tip Here, or Change/Remove your Email Address: http://www.tech-assist.org/secure/tip/main.htm Lost Password: http://www.tech-assist.org and select "Lost your Login Info?". Email Archives: //www.freelists.org/archives/techassist/