Looking for Sun EPA 75 IR chips or the pn's

[capriguy7]

Looking for Sun EPA 75 ir chips

 

[DCJets]

I have a dejá vu...

 

[DCJets]

But did you clean the optical unit? The mirrors and the lenses of the tubes? In and Out? Especially inside.

 

[capriguy7]

But did you clean the optical unit? The mirrors and the lenses of the tubes? In and Out? Especially inside.

No. But have had it trouble shot to IR chip defect

 

[DCJets]

Ok. Which way? Assume you don't have manuals or wirings either.

 

[capriguy7]

Well I did manage to find the pn
Now I just need to find the parts.
I have an operating manual which has a very simplified wiring schematic in it.
Pn 7049-0961

 

[capriguy7]

No. But have had it trouble shot to IR chip defect

Did clean Optics no change

 

[DCJets]

The IR chip has two channels. Does it stupid things for HC and CO or ist only one side affected?
The EPA 70 uses the same patent number. It basically has the same optical unit installed, but since solely going for CO, the second, reference, tube ist just a tube. Completely empty, without any lenses installed. And, the same sensor, but the HC-side not connected.

The following is all EPA-70. See the empty tube and the Green and Red cable hooking up with nothing.

Lens removed for cleaning from inside side.

 

[capriguy7]

It's only the CO that is not able to be adjusted. And as you can see only the two paper tags are still on the unit. Also this was inspected Nov 6th 1975 and Aug 11th 1979. So this unit is minimum 50 yrs old
No casting marks can be found.