Hi guys, I 've just replaced the belts in my Sanyo M7790K and after i put everything together I have the following problem/issues: The buttons for REW/FF and Play do not stay pressed when I press it for either rewind or FF or play a tape. If I keep them pressed manually (finger force) the operations work but, as soon as i get my finger off the button it will release itself and operation will stop. I have checked the AMSS solenoid as well as the Power leaf switch but cannot find a fault there. What else might be? Do you have any ideas? I have the boombox open but I'm not sure where and what to look for. I'm suspecting some part had moved out of its position while I was replacing the belts maybe? I don't think I lost any part from the cassette mechanism, i was extremely careful with the belt change.
I only have a handful of soft touch boomers and very little experience with them, do you have a service manual, it looks like it has all the specs. https://archive.org/details/manual_M7790K_SM_SANYO_EN/page/n15/mode/2up With the older boomboxes, the lube get sticky or hard on the moving/sliding transport parts and they get the same symptoms. Sometimes a tiny spring loses it's compression and won't pull a latch enough to hold it the plate in position. C2G probably has four versions of this box, hopefully he'll check in.
Thank you, will check that, although not sure which exact part to check while looking at the service manual...
After about 4 hours of frustration and while I was about to put the whole boombox chassis back into its cabinet and call it a lost fight, i have found the PLAY/REW/FF locking lever... In photo1 we're looking at the cassette mechanism upside down and from the back side of the chassis. I have circled with RED the area where the locking lever and its spring reside. In photo 2 there is a close up of the locking lever and the spring. Notice the locking lever is on the left of the spring, that's not right; that was the problem... The spring should be on the left side of the lever and constantly pushing it to the right, that's not the case as you can see in the photo; it looks that somehow while I was replacing the belts the spring jumped over the lever and moved to the right where it would not engage anything at all. ( I believe the spring is mentioned in the manual as: MC96 141 2 8539 46700 Spring, Plate Lock. Not sure about the lever but i think it is the: MC79 141 2 7319 53600 Lock Plate ) In Photo3, Photo4 and Photo 5 I have positioned the spring back into its place which is on the left side of the locking lever. I took photos from different angles so you can see how it is supposed to be. My 7790 is back in business!
Great update! This is sure to help someone else out there in years to come who searches for this model and is now warned to look out for this!
Yes, I tried explaining you that to you when you asked me the question in the YouTube video. I was trying to explain about that little tiny lever plastic. Has to go in the channel just correctly and when you take it apart it can fall out of its slot and I didn't have a good picture to show that to you. I'm glad you finally figured it out cuz that happened to me as well and I have one more to repair that I have yet to unbox which I'll be doing in the next few days or so
