TI99/4A "Coffee cup warmer" buzz

[eightbit]

Hi all,

 

In an effort to get back what I once had (and then some) I recently scored a really clean beige TI99/4A for the whopping sum of $10. It arrived the other day, with minor issues. First one key (the "Q" key) did not appear to work but after removing it and cleaning with alcohol it came back to life. I tested all other keys and the keyboard is 100% working...whew.

 

The picture is crisp and everything appears to be working fine. The plug that goes into the unit for power was separating (the wires were not severed however) so I sealed it with a glue gun and patched it up with some electrical tape. The PSU works fine but "hums". I suspect I will need a new one one day, but it is working for now.

 

The one concern I do have is that the area that is considered the "coffee cup warmer" has an audible "buzz". I can hear it clearly in a quiet room or when I put my ear up to it. I had TI99 computers in the past and I do not recall this anomaly, but it could have very well been there on previous computers and I was in noisier surroundings.

 

What is that under there? Some sort of power regulator? Should I be concerned? I am planning on outfitting this unit with an F18A that is on the way, but I would hate to invest all of the time and effort of installing it into this unit just to find it dies on me shortly after.

 

Any thoughts are greatly appreciated!

[+Ksarul]

The area under the "coffee warmer" has the power supply that converts the input power from 22VAC to the various DC voltages used in the console. The DC power supply is a separate board--and easily replaced if it goes bad.

[eightbit]

Nice, thanks for confirming. The noise is not bothersome really, but it is really good to know it can be replaced easily should anything go wrong.

[+arcadeshopper]

I have both power supplies in my store if needed

 

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[eightbit]

I have both power supplies in my store if needed

 

Sent from my LG-H830 using Tapatalk

 

 

I might be visiting your store soon Can you post the link in this thread?

[+arcadeshopper]

www.arcadeshopper.com

 

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[eightbit]

www.arcadeshopper.com

 

Sent from my LG-H830 using Tapatalk

 

 

Well that was straight forward enough I will check it out, thanks!

[Casey]

I'm fairly certain the beige 99/4A I had many years ago (bought new when TI was liquidating them) had a buzz from that area when the computer was turned on. It worked for years and years and always did that.

[+acadiel]

Mine have always had a slight buzz.

 

It's one reason I replaced both of the PSU components with a single multi-volt power brick. That thing is silent...