Apparent heat trouble with a 3279 terminal

[budwinkle370]

I have an IBM 3279 terminal with a 3174 controller I use to connect to my hercules/MVS 3.8j make-believe mainframe. The 3279 works fine for a while but then clicks loudly 3 times and the power dies. If I let it sit long enough (usually overnight) it works again - for a while. I think but am not sure it is heat related. I pointed a fan in the appropriate direction, added some wide masking tape, funneled the air into the bottom of the case and it runs longer but still eventually cuts off. Are there any old IBM field engineers out there who may have a suggestion as to what's wrong and what I can do about it? Thanks for any responses.

Buddy Bell

 

[NeXT]

Has the terminal seen a recap in the last 35 years? Failing a thermal issue (you mentioned it lasts longer with increased ventilation) it sounds like something is falling out of value the longer it is running. I've had a few monitors do that.

 

[g4ugm]

i have asked a couple of ex-ibm CEs, one of whom I know worked on 3279's, but I suspect all they did was board swap.

 

[budwinkle370]

No, I don't think it has had a recap. I guess I have no choice if I want it fixed but must admit I am a bit afraid given my level of hardware repair experience. It at least works some of the time now. Thanks for your reply.

Has the terminal seen a recap in the last 35 years? Failing a thermal issue (you mentioned it lasts longer with increased ventilation) it sounds like something is falling out of value the longer it is running. I've had a few monitors do that.