Grundig RR 640 Professional by Anders posted May 18, 2018 at 11:00 PM After a long break from buying boomboxes I came across a Grundig RR 640 in a thrift shop and fell in love. It has the right look, it's sturdy as hell, it's in really nice condition and it weighs a tonne. It had a note on it saying that the tape deck doesn't work and I figured it's probably the belt. I got it home and sure enough, I found not one, but two belts in terrible condition in there. One was completely melted away and the other was intact, but stretched out. I have been looking around the internet to see if I could find any info on the type of belts needed but I've had no luck at all. I was hoping someone on this forum might own a boombox of this model or know where I could find the info.
I am sure Stereo2Go members would love to see some pictures. Regarding the belts if they are a normal (1mm square ?) section then your best bet is to buy a mixed set on Ebay and find the ones that fit.
There we go, I tried and failed to add a picture before but I managed it now I think one of the belts is a really short 1mm square one and the other is flat and about 4 mm wide. I could probably open it up again and run a piece of string around the rollers to try to measure the length of the belt but it's really cramped in there so I'd have to really dismantle it to get that done.
are you sure there is only two belts? here is a kit of 4 belts for RR640: Grundig RR-640 RR 640 Belt rubber belts Radio Recorder Ghettoblaster Normally I stay away from eBay sellers and buy belts from Turntable Needles or Marrs Communications, but I can vouch for this seller: I bought a set for Nak LX-3 from revox-de, the belts were of top quality and the end result up to Nak specs!
huh, thank you! Makes me wonder where the other two belts are supposed to go. I might have to open it up again and take a more serious look around.
My advice: take A Lot of photos of the cassette mechanism! If you see any orange (amber) coloured gear(s), measure their diameter/count teeth and start looking for the new ones off eBay. Saves you some headaches in the future!!! Check my post on D8444 gears at Boomboxery, folks there say that Grundig also used that infamous plastic, not just Philips/Magnavox. And some gears are now available off eBay, Grab them while you can! Awesome bbox, by the way, love its looks!!!!!
Oh wow, I'll have to do a proper teardown and cleaning then. Are the orange/amber gears at a special risk of breaking? My plan is to use it as just a radio with my FM transmitter for now and get to fixing it properly when I have a little more time on my hands. Maybe this summer. I'll have to check out your post.
