Maker Pro
Maker Pro

Tektronix 2445 Scope Repair? ANY help would be appreciated!!!

Prevost

Jan 6, 2017
1
Joined
Jan 6, 2017
Messages
1
Hi, my name's Alex and this is my first post to the forum, so please be nice :D
I was wondering if someone could provide me some insight with what might be wrong with my Tek 2445 Oscilloscope.
I finished an electronic technology program in CEGEP (Quebec's equivalent of college) and upon graduation, our department let us take some old lab equipment home with us. I ended up with this scope that kinda only half works...
I would REALLY love some help fixing it (if its at all possible). I'm pretty lost right now....

I downloaded the service manual and determined that there are at least three problems with it:

1) The most obvious issue appears to have to do with the crt. I dont know WHAT is wrong, just that it's almost certainly related to the crt. Basically, it's entirely capable of displaying a clear and concise signal (i havent hooked it to any circuits yet, i also don't own a function generator) as i have been able to calibrate it. However, the portion of the readout that should be displaying information like the channel, frequency, amplitude, Vpp, etc... of a signal is garbled and unreadable. (I'll attach a picture).
I have only been able to (just barely) decipher the text displayed when it boots (or when i force it) into the "Diagnostic Monitor".

Which brings me to Problem #2:
It consistently fails Diagnostic Test 04. From what i understand, this is related to the device's readable memory... something called EAROM (Electrically Alterable Read Only Memory)?
The exact error code is 01 which, according to the service manual indicates: quote "Parity error on read (bit 0 set)". I'm not certain what this means or how i may be able to fix it? I know how to run the Exercisers, #2 of which allows the user to examine the device's memory locations, of which there are 100 (decimal)/63 (hexadecimal) and their parity.

3rd, it also appears to fail a kernel test about 50-60% of the times i try to boot it up. Everything lights up but then goes out again (including the display), leaving nothing but a blinking Trig'd led and the fan to tell you that its powered on at all.

This is everything i know and understand about the issues, so if anyone has ANY insight at all, it would be very much appreciated.

PICS:
20170106_175331.jpg 20170106_175406.jpg 20170106_175458.jpg 20170106_175610.jpg 20170106_183054.jpg
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
Moderator
Jan 21, 2010
25,510
Joined
Jan 21, 2010
Messages
25,510
I think your best bet would be to find a forum dedicated to Tektronix maintenance and repair.

I'm sure there was one, but I can't remember its name.

If nobody else knows, I'm sure you could ask here.
 

shrtrnd

Jan 15, 2010
3,873
Joined
Jan 15, 2010
Messages
3,873
People have recommended some forum out there that I don't remember the exact name of, that deals specifically with Tektronix equipment. Google it and ask them.
Frankly, from what I see in your pictures, you may have a focus or blooming problem (that can be adjusted), but
your root scrambling error looks to me like it's displaying in some language other than English.
Does the scope have a menu for changing the language?
 

mister natural

Apr 6, 2017
1
Joined
Apr 6, 2017
Messages
1
Hi, Alex. I recently acquired a Tektronix 2440 scope, similar in design to yours. It didn't have any display, but since there was some light flashing during booting and at shut down, I was convinced that high voltage was there. After a thorough cleaning of all the accumulated dust, which alone made no difference, I carefully pulled out all the ICs that were on sockets, one at a time, and re-seated them, making sure no pins got bent. Since then it has been working perfectly. So give that a try, the scrambled alpha-numeric display could well be attributed to a poorly seated ROM chip, which are used to generate the text and are exchangeable since they can be programmed for different languages. Good luck!
 
Top