Electronics > Repair
Wavetek 2520a 0.2-2,200MHz RF sig gen repair
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dazz1:
Hi
I removed and isolated the main board.  That takes about half an hour.   I applied power and the positive input power is shorted.  None of the +/-15V voltage regulators or caps are warm.  It is most likely a shorted cap on the input side of the voltage regulators.  I have already replaced 4 but there are plenty more to fail.

I have decided to go through and replace all tant caps on the +/-18 volt supply rail.    This includes replacing the no-name-brand new tant caps I sourced from the local hobby electronics shop. 
You may be wondering why I didn't do this from the start.

When I started, I didn't know if the 2520a was fixable.  It is old enough to include obsolete irreplaceable parts.  The eprom code and LCD displays cannot be replaced.
Now that I have had the 2520a running for at least a couple of hours before faulting again, I know that it is fixable. 

I also plan to replace the battery backed ram.  At 32 years of age, it should not still be working.
I am trying to find someone somewhere who can burn the eproms.   That process would give me a backup of the eprom contents. 

It is going to take me a while to get the parts and complete the install so this topic will probably be silent for a while.

Dazz
TheDefpom:
How many EPROM's are there? I could only see one from the photos and diagrams you posted, and that was a 27C64.
dazz1:

--- Quote from: TheDefpom on June 10, 2021, 09:43:37 am ---How many EPROM's are there? I could only see one from the photos and diagrams you posted, and that was a 27C64.

--- End quote ---
Hi
There are five.  1x 64 and 4x 128.
I have not been able to find an accessible eprom programmer.  Even if I did, I suspect find a PC that can run the code would be a problem.

Dazz
tautech:

--- Quote from: dazz1 on June 10, 2021, 10:46:10 am ---
--- Quote from: TheDefpom on June 10, 2021, 09:43:37 am ---How many EPROM's are there? I could only see one from the photos and diagrams you posted, and that was a 27C64.

--- End quote ---
Hi
There are five.  1x 64 and 4x 128.
I have not been able to find an accessible eprom programmer.  Even if I did, I suspect find a PC that can run the code would be a problem.

Dazz

--- End quote ---
Do you have a W10 PC ?
If so Defpom and I can make it happen.
dazz1:
Hi
W 10PC = Windows 10 PC ??   Yes I have several. 
Code that I wrote for 8086 PCs in the 1980's and 1990's  won't run on Win10 without some retro conversion software.

Dazz
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