Need help to identity 40 pin chip

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I have this 40 pin chip that needs to be replaced but, the info on the chip does not correspond with anything I have searched for. It appears it may be a Fairchild part from the 80's, code date 8325. The # 120017-1 A does not come up in any database I searched on line. It is part of a temperature monitor system made by Goldline for solar water temperatures. It's input are time of day and 6 separate temperature readings in the solar system, which then are shown on the LC Display. I would like to replace it with the same part or a replacement part.Any help would be appreciated.

Hello nmrrmember.

Sorry, I’m not finding anything to help me determine what this is. Someone else in the community may have more experience with this type of device and be able to identify it though.

Thanks Jerry, Yea I been at this for a week trying everywhere, Digi Key, Mouser, On Semiconductor, you name it, I’ve been there. I just don’t understand why the #120017-1 doesn’t come up with anything on the web.


Hi nmrrmember,

It’s pretty likely that it is a custom controller produced only for Goldline. I found some contact information for them if you would like. Don’t know if it is still current:

Goldline Controls Inc., 61 Whitecap Dr., North Kingstown,
RI 02852 • 800-294-4225 or 401-583-1100 • Fax:
401-583-1200 • technical_service@goldlinecontrols.
com • • Goldline (formerly
Independent Energy) controls

I found that within this possibly useful old document on trouble shooting solar water heating systems.

Hi nmrrmember.

For some reason it appears, that this topic content got deleted.
However, the chip is most probably Fairchild’s MK3870.
(Based on the era, oscillator and supply pin locations and other chips on the board).
The bad news is that it is mask programmable, thus finding exactly the same chip
(with same ROM firmware code) may be extremely challenging.
Actually, it may be easier to replace the chip with, for example, an Arduino module and write
a new firmware code for it.

I hope this helps.
heke, AsamaLab.

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Wow, thank you, I will check this out.


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