Onkyo TA-R240 Cassette Deck power transformer issue?

[93SCMax]

Hoping someone can give some guidance on how to troubleshoot a transformer. I'm the original owner of this cassette deck. It's been my garage deck for some time but I haven't used it much. Sometimes it turns on with the power button, sometimes it doesn't. I opened the deck up and cleaned the power on switch with CRC electronic contact cleaner, and it didn't help. I lightly tapped the transformer with the handle of a screwdriver, and it would come on and play. Buttoned it up, turned it off, then try to turn it on again, and no power. If I tap the side of the housing near the transformer, she comes on and runs.

Are there some checks I can make to determine if the transformer is faulty and needs replacing, or is there another component that I also need to check? I have a multimeter and some mechanical skills. I would like to get it back to normal so that it powers on 100% of the time when I press the POWER button.

Thanks for any advice you might offer.

 

[Bradbrews]

It’s most likely the switch. There’s not much that could happen in the transformer. I suppose you could check all the connections and reflow as needed but it’s probably the switch.
Bypass it and use a power strip switch for a while to verify it.

 

[93SCMax]

Thanks for your input. I initially suspected the switch but my initial cleaning didn't yield the results I was hoping for. I can clean it again with DeOxit but it baffles me that many times it powers up, but when it doesn't, a tap on the transformer, or the side of the deck (if top not off), usually gets it powering up. I can reflow the connectors to see if that helps. I was jumping to conclusions that it may be the transformer since it powered up when I tapped on it.

I've already removed it from the garage system so I have something that actually works. I'll keep troubleshooting it with the input I receive in this thread.

Thank you.

 

[93SCMax]

I want to thank Bradbrews for redirecting me back to the power switch as the likely failure mode. I resprayed the switch, with DeOxit D5 this time, and proceeded to work the switch on-off for 20 or more times., I also used some compressed air to dry or push out the excess DeOxit.

The unit now powers on every time.

To summarize, my intermittent power issue was a dirty or poor contact with the power switch, and not the transformer as I listed in my title. I would like to change the title to more accurately describe the real problem, but I don't believe titles can be edited.

Thanks again Bradbrews for helping out.