wavetek waveform generator model 75 no response :-(((

Hey all,

Thanks in advance for any help on this. I'm a high school physics teacher and I came across this device in a surplus warehouse and I'm hoping to get it working if possible. It is a wavetek brand waveform generator model 75.

the device turns on but the LED display panel is all black blocks and no di gits. I've read the manual and tried the reset procedure of hitting setup

3 times, then f2 and then f3 but there is no response even during this proc ess. I have measured the signal from all of the outputs and no response.. I really hope this is a common problem and is fixable, this would be a ver y meaningful device for my students in our classroom.

has anyone had experience with this problem on this or a similar device bef ore?

thanks!

dave

Reply to
David O'Dell
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I came across this device in a surplus warehouse and I'm hoping to get it working if possible. It is a wavetek brand waveform generator model 75.

digits. I've read the manual and tried the reset procedure of hitting setup 3 times, then f2 and then f3 but there is no response even during this process. I have measured the signal from all of the outputs and no response.. I really hope this is a common problem and is fixable, this would be a very meaningful device for my students in our classroom.

before?

There don't seem to be a service manual up front, I didn't fully look

But what you describe sounds like bad caps, electrolytic types. Most likely from sitting around and one in a critical area dried out.

Also, that unit could have a lithium cell in it for memory, some times they get bad enough to where they hold down the start up process of a diode isn't being used to isolate it.

I would take it apart and look it over..

Jamie

Reply to
Jamie

her and I came across this device in a surplus warehouse and I'm hoping to get it working if possible.  It is a wavetek brand waveform generator mod el 75.

digits.  I've read the manual and tried the reset procedure of hitting se tup 3 times, then f2 and then f3 but there is no response even during this process.  I have measured the signal from all of the outputs and no respo nse..  I really hope this is a common problem and is fixable, this would be a very meaningful device for my students in our classroom.

efore?

Do you have access to a voltmeter and an oscilloscope? I would contact the manufacturer and explain to them that you are a teacher and need some help in fixing one of their products for use in high school classes and see what they offer to do. Tell them even a schematic would help, but only if they don't seem very helpful.

Reply to
hrhofmann

I came across this device in a surplus warehouse and I'm hoping to get it working if possible. It is a wavetek brand waveform generator model 75.

digits. I've read the manual and tried the reset procedure of hitting setup 3 times, then f2 and then f3 but there is no response even during this process. I have measured the signal from all of the outputs and no response.. I really hope this is a common problem and is fixable, this would be a very meaningful device for my students in our classroom.

before?

The manual shows a 16x2 LCD. (I posted a link to the service manual in a different message) BTW, it is Wavetek Model 75 Arbitrary Waveform Generator, which means you need to design the shape and amplitude you want at the output. From the manual I found online, it was built around

1985.

The first thing I would do is look at the three outputs from the power supply. +5, +15 and -15 volts. Is it a simple linear power supply with a LM7805 three terminal regulator for the +5 VDC and a LM125 (or LM325A) IC regulator for the + & - 15 VDC supplies, so it will be easy to test & repair.

It's also possible that the LCD has failed, due to age but most of these are generic parts.

The unit is based on a 6303 MPU, which is the Hitachi version of the Motorola 6803. It has a 27C256 EPROM with the firmware, and a 64 Kb static RAM. It should be simple enough to troubleshoot.

BTW, there is a newsgroup specifically for test equipment questions: news:sci.electronics.equipment

Reply to
Michael A. Terrell

Thanks in advance for any help on this. I'm a high school physics teacher and I came across this device in a surplus warehouse and I'm hoping to get it working if possible. It is a wavetek brand waveform generator model 75.

the device turns on but the LED display panel is all black blocks and no digits. I've read the manual and tried the reset procedure of hitting setup

3 times, then f2 and then f3 but there is no response even during this process. I have measured the signal from all of the outputs and no response.. I really hope this is a common problem and is fixable, this would be a very meaningful device for my students in our classroom.

has anyone had experience with this problem on this or a similar device before?

thanks!

dave

+++++

My only Wavetek generator , of that era, repair experience, was a shorted

22uF tantalum on a power rail and so a "dead" machine
Reply to
N_Cook

Hi I've the same instrument. Mine doesn't lit up at all. Power supply is good but the problem should be in the logic circuit. I'm looking for the service manual but i can't find it anymore at rowland website linked by Michael. Have you downloaded a copy of the manual before that was deleted from site? In this case, can you send me a copy?

Reply to
gianluca.locri

try archive.org

Reply to
N_Cook

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