Judging from the date codes on the chips my 224 current source is a 1986 model. That makes it 35 years old. And although the Richey capacitors did not fail yet it is high time for a replacement.
Here is the list of capacitors to be replaced:
|Designator||Description||Digi-Key part no.|
|C103, C119, C120||10μF, 25V||493-13463-1-ND|
|C121, C122||1000μF, 35V||493-1322-ND|
|C312, C315, C316, C324, C325, C327||10μF, 25V||493-13463-1-ND|
|C317, C323||4.7μF, 350V||493-1437-ND|
The lead spacing of some capacitors are not a perfect fit so if you want to be a stickler for neatness you may need to check each type.
The two EPROMs are easy to spot. They are socketed and have a sticker with the firmware version on them. Try to extract them gently.
To read the contents I used my TL866II. The chip is the following. If you need the files send me a message. My firmware version is B1.