This page is devoted to the restoration of my Tono Theta 5000E terminal. I hope you enjoy it!
Tono Theta 5000
Complete, automatic send/receive of Morse code (CW), Baudot code (RTTY) and ASCII code (RTTY) with the addition of any video monitor for display. The Perfect addition to complement any amateur radio installation. Below are a few of its outstanding features:
* 7-channel Battery Back-Up Memory
* The Tono Theta 5000E has seven keyboard-selectable, non-volatile, random access memory channels each of which can hold 64 characters. Data in these memories is alterable at any time and is retained when power is removed. Messages in these memory channels can be repeated 1 to 9 times via keyboard command. All channels may be daisy-chained for continuous read-out. Channel number in use is indicated on display.
Lots more info about this unit can be found here: TONO THETA 5000 - specifications
I got the unit in unworking condition, having a known fault, and without keyboard. But, besides this, it was extremely dirty of tar from a really heavy smoker. It was lots worse than the pictures show, trust me!
Just to show how bad the tar layer was, here you have some samples of what is below it:
Once the main board was removed, I found all metal case was... well, look at it:
The power supply was below a large dust and tar layer:
And, of course, picture tube neck, which gets pretty hot, was completely darkened with baked tar residue:
Flyback and other parts were also badly affected:
See what is below the layer!
This is a detail of the power supply assembly, once removed from its place. Really ugly looking!!!
But beauty is sometimes in the inner side:
So it was time to clean the unit... armed with alcohol, cotton swabs, rags, paper towels, patience and so on.
After lots of hours, these are the results. Now you can look at the chassis!
The picture tube had been cleaned but not fully:
This is the tube and the monitor assembly properly cleaned:
And the power supply is now looking fine!. I replaced the rectifier bridge, as it was faulty:
General look of the unit before putting back main board:
What took more time to clean was the main board, as it has lots of components and access to the board is pretty limited between them. But result is good:
This is the unit with all modules back on it:
OK, now that unit was assembled, it was time for an smoke test!
First power on...
Well, at least it powers up. GREAT!!!
I need to clean the switches and pots, as they are all electrically very dirty. And check the unit with some on-air signals...
Page INDEX
Unit as received
Cleaning
Testing
More to come soon... keep tuned!