SX-727 function bulb holder material

[thxdave]

Picked up a very clean SX-727 this weekend and need to replace the Stereo Indicator bulb and the AM lamp next to it. The heat (and years) have turned the bulb holder material into goo and then stone. The bulbs are basically cemented into the holders with a lot of the material sagging over the fronts of the bulbs rendering them extremely dim. I managed to scrape enough material from the front of the openings to let the lights shine through but was wondering what others have done to replace this white foam (?). Most of the bulbs are still working but I'm not sure what I'd do if they were all out and I had to chisel the dead ones out.

 

[fernarias]

They are made of abs plastic(non flammable and contain boron which is why they turn yellow). You might be able to find this part on ebay (there's one on sale right now cheap) as people who don't know and/or don't care how to fix are parting them out. If you are trying to repair, there are many places that sell abs sheets in different sized (and thicknesses) that you can use. Make sure you use an abs glue (not testers, it's crap) instead of epoxy (epoxy is best for porous materials). Abs glue will melt and then solidify abs.
It's funny that my model building hobby is giving me the skills to fix/restore plastic parts on these old hi-fi equipment.

 

[thxdave]

I'm not sure that this holder material is ABS plastic. It's more of a foam consistency. If you press it with the tip of a screwdriver (or similar) in the area between the lamps, it still has some give to it like foam. I know what you mean by yellowing ABS as my Marantz 2275 had some drooping plastic but it wasn't the same material as this. Look at the photo and you can see the odd texture of the material:





I had to scrape and gouge out the material before I could remove the AM bulb. This goo had attached itself to the bulb body. The Stereo indicator lamp to the immediate left had melted a bit, but not as bad as the AM bulb......must have been owned by an AM radio lover, huh? Then, if you look at the Aux lamp holder (below), you can see where it melted so badly that it all but shut off the light from view (top center):



Just curious.....did Pioneer always put those little silver reflectors on their fuse lamps? Never seen that before.

 

[fernarias]

Gack! From your pictures it looks more like polyurethane foam. Refurbished two 727s and didn't notice (owners like the look of the original lights). What to do depends on your skills (no skills buy replacement, skills rebuild this part of the light housing). If it were me, I'd take all this stuff out and then rebuild with abs boxes made from white abs sheets and replace with LEDs (using a warm white diffused LED). I've been using abs sheets to repair the tangs on the light holders for the x50 receivers and similar to great results.

 

[thxdave]

Got my bulbs yesterday and I'm busy digging out the dead ones from that ossified crud. For now, I'm going to dig it out enough to slip in the new bulbs but I'd like to remove all of it.....someday. Also, I'm NOT loving those weird little plugs Pioneer used for speaker connections. Does anybody have a source for these? I only need one.