I have a policy that when a boombox has been worked on before, I avoid them like the plague.
Consider this: I have this boombox, a grail if you will.... I rebelted, dunked, cleaned, deoxit.... the works, to the boombox. However, for 3 years, I refused to reassemble it back into the shell because the music scan/search feature was not working. On another boombox, I would not care. On this one, there is good reason to want it working 100% perfect. So from time to time, I would do some more work to it. The frustrating part is that everything I tested appears to be in proper working order. Nevertheless, the AMSS light will not illuminate when that feature is turned on and none of the search feature was working.
Recently, fatdog gave me the heads up on a set of manuals that included the one I needed. Some negotiations and big $$'s later, we had a deal for just that one manual. Yesterday, my high $$ service manual came and today, I dug out the chassis and reviewed the connections. I suspected something wasn't exactly right because the way it was behaving suggested as much. Still it was that way when I got it and everything was connected in such a way that looked OK. Nothing seemed out of place. Nevertheless, without documentation, it was impossible to know whether it was all connected correctly. This is one of those boomboxes where wiring is tethered all over the place, like a rats nest.
So a quick review of the connections and comparing to the wiring diagram in the manual found the problem. The AMSS board had 4 connectors tethering it to various PCB's. 2 of the connectors was swapped. Both connectors were the same size/type and the lengths were approximately equal so it was easy to do but they went to different PCB's. It was that way when I got it so presumably, it was worked on before and the connectors swapped because I can't believe it came from the factory that way. The big $$ manual, it seems, was totally worth it.
So, in support of my argument to PASS on any boombox where any suggestion exists that it had been tinkered with before, my misconnected/molested boombox represents a perfect example why. Enormous amounts of time/expense can be wasted when something is connected wrong but no documentation exists to support or contradict it either way. When a boombox is received and not working right, the default presumption must be made that it is properly assembled as received and therefore used as a guide for proper reassembly after service. If just a wire or two was misconnected, then some educated guessing is often enough to correct the issues. However, when more repairs/modifications are performed, then it's almost best just to send the dam- thing back since almost surely, it will be a diagnostic black hole. To be sure, every component can be tested and found to be in perfect working order, yet if not connected properly, it will be impossible for it to be working 100% right unless the misconnected wiring is corrected.
From experience, I have corrected many such misconnections. They are more common than you think. Sometimes, intuitive guidance can be relied on and on certain circuits such as cassette motor drive connections, some reverse engineering is all that is necessary to figure out if it's tethered correctly. However, some connections simply is not easy to figure out. This boombox was my most frustrating one for 2 reasons. (1) it belongs to me so it's not as simple as just sending it back unfixed and (2) it's a grail so I was determined to get it fixed.
Anyhow, here is a suggestion for any of you guys working on boomboxes that you aren't familiar with -- do everyone in the hobby a favor and take many pictures, redundant ones if necessary to ensure you reassemble everything back the way it was. Someday, you may want to sell, trade, or commission someone to repair it for you. If it was not reassembled correctly, the issues mentioned above will definitely come into play and cause grief. The only question is how much grief and whether it is your grief or someone else's. If there is a suspicion that anything is not properly reassembled, then at least mention that to the repair person or new owner. At least they can approach the boombox differently when trying to correct issues.
Consider this: I have this boombox, a grail if you will.... I rebelted, dunked, cleaned, deoxit.... the works, to the boombox. However, for 3 years, I refused to reassemble it back into the shell because the music scan/search feature was not working. On another boombox, I would not care. On this one, there is good reason to want it working 100% perfect. So from time to time, I would do some more work to it. The frustrating part is that everything I tested appears to be in proper working order. Nevertheless, the AMSS light will not illuminate when that feature is turned on and none of the search feature was working.
Recently, fatdog gave me the heads up on a set of manuals that included the one I needed. Some negotiations and big $$'s later, we had a deal for just that one manual. Yesterday, my high $$ service manual came and today, I dug out the chassis and reviewed the connections. I suspected something wasn't exactly right because the way it was behaving suggested as much. Still it was that way when I got it and everything was connected in such a way that looked OK. Nothing seemed out of place. Nevertheless, without documentation, it was impossible to know whether it was all connected correctly. This is one of those boomboxes where wiring is tethered all over the place, like a rats nest.
So a quick review of the connections and comparing to the wiring diagram in the manual found the problem. The AMSS board had 4 connectors tethering it to various PCB's. 2 of the connectors was swapped. Both connectors were the same size/type and the lengths were approximately equal so it was easy to do but they went to different PCB's. It was that way when I got it so presumably, it was worked on before and the connectors swapped because I can't believe it came from the factory that way. The big $$ manual, it seems, was totally worth it.
So, in support of my argument to PASS on any boombox where any suggestion exists that it had been tinkered with before, my misconnected/molested boombox represents a perfect example why. Enormous amounts of time/expense can be wasted when something is connected wrong but no documentation exists to support or contradict it either way. When a boombox is received and not working right, the default presumption must be made that it is properly assembled as received and therefore used as a guide for proper reassembly after service. If just a wire or two was misconnected, then some educated guessing is often enough to correct the issues. However, when more repairs/modifications are performed, then it's almost best just to send the dam- thing back since almost surely, it will be a diagnostic black hole. To be sure, every component can be tested and found to be in perfect working order, yet if not connected properly, it will be impossible for it to be working 100% right unless the misconnected wiring is corrected.
From experience, I have corrected many such misconnections. They are more common than you think. Sometimes, intuitive guidance can be relied on and on certain circuits such as cassette motor drive connections, some reverse engineering is all that is necessary to figure out if it's tethered correctly. However, some connections simply is not easy to figure out. This boombox was my most frustrating one for 2 reasons. (1) it belongs to me so it's not as simple as just sending it back unfixed and (2) it's a grail so I was determined to get it fixed.
Anyhow, here is a suggestion for any of you guys working on boomboxes that you aren't familiar with -- do everyone in the hobby a favor and take many pictures, redundant ones if necessary to ensure you reassemble everything back the way it was. Someday, you may want to sell, trade, or commission someone to repair it for you. If it was not reassembled correctly, the issues mentioned above will definitely come into play and cause grief. The only question is how much grief and whether it is your grief or someone else's. If there is a suspicion that anything is not properly reassembled, then at least mention that to the repair person or new owner. At least they can approach the boombox differently when trying to correct issues.