I happened to have that issue in the hard drive. Page 49 answered my questions exactly. I guess I will likely want a few blackened screws on hand just in case. Thank you for the reference!

Wayne
WB4OGM

On Saturday, April 20, 2024 at 08:22:49 PM MDT, Michael Hanz <[email protected]> wrote:


In the SCR-274-N maintenance manuals there is a section on "Servicing faulty receivers" that provides a sequence of removal of various parts, distinguishing the screw colors as "bright" and "black".   In the T.O. No. 16-40SCR-274-5 that was revised 25 July 1956 , it's page 49.

73,
Mike  KC4TOS

On 4/20/2024 7:59 PM, hwhall--- via ARC5 wrote:
Hi, Dave!  The screws I'm looking at are all the externally visible ones, when everything is assembled.  They don't appear to have been put on randomly -- the darker ones I've noticed so far are only those securing that "top cover" underneath the rim of the front panel plate (the top cover has slots to allow removal of the cover without fully extracting the darker screws).  It looked like they might have been deliberately done.  But if it's likely not original, then I don't have to consider whether to have darker screws at the ready.

Wayne
WB4OGM

On Saturday, April 20, 2024 at 05:40:44 PM MDT, David Stinson <[email protected]> wrote:

On 4/20/2024 6:10 PM, hwhall--- via ARC5 wrote:
> Some of the SCR-274-N receiver sets I'm working with have silver colored
> screws in some exterior places & darker colored (almost black?) screws
> in other exterior locations...


If you remove the top cover of a 274N (or ARA, ARC-5)
  receiver, you see an internal shield over the tuning
capacitor.
The black screws bypass the top cover and screw
into receptacles holding this internal shield in place.
By removing just the "silver" screws, you can pull
the top cover without disturbing the internal shield.
Receivers which have been disassembled and reassembled
are often put back together with mixed screws.

GL OM ES 73 DE Dave AB5S