Hi guys. I've spent a lot of time servicing this unit and have replaced the belt and adjusted speed so its at least somewhat ok. There is one glitch however, when I press the stop button sometimes it actually mimics the behavor of the play button. And when I press play button sometimes it does a FF. It is very irritating. I have tried cleaning ribbon pins and ic pins with IPA. I couldnt see any damage under the hood. I have some pictures of the board which the buttons are registered on. Does anyone have any advice for me to try figure out this glitch?
Given the buttons use a resistor ladder, any increased resistance on the buttons will render this behavior. Solution is to clean the buttons themselves with contact cleaner (Kontakt 60, Deoxit, etc.)
Hi Valentin. Long time no see. I understand your logic that the increased resistance per button pad could cause this behaviour. I am not sure how I can clean actually clean these buttons though as they are completely sealed that that orange polymide (or similar) film. How do you get contact cleaner in there? Also would WD 40 specialist cleaner also work? It's what I usually use for pots
There are 2 options: disassemble the button and clean manually or simply spray some contact cleaner over and pressing the button many times. The latter usually works just fine. And no would recommend against WD-40 or any similar generic cleaners, even the ones marketed as good for electronics. The generic ones are no good for this application. There is a story here on the forum with someone cleaning a DD10 PCB with that and it left a lot of residue which was very hard to clean.
Thanks Valentin. Your knowledge on walkmans is very impressive. Regarding the WD 40 Specialist Contact Cleaner leaving residue that is weird as its supposed to completely evaloprate and leave no residue. If I go the DeoxIT route it looks like there are 2 products for 2 seperate purposes. DeoxIT D5 - to remove oxidisation and leaves a microscopic layer of protective film (I dont know what its made of as its apparently a secret) DeoxIT F5 - also removes oxidisation but also leaves layer of lubricant. Ideal for potentiometers etc that have friction WD 40 Specialist Contact Cleaner - 100% solvent, it leaves no protective layer and no lubricant Kontakt 60 - an agressive acid that will effectlivly eat through oxidisation, but will sit on the metal and continue to eat it. Probablly not ideal for our switch as it wont evaporate In the future Im going to use DeoxIT products and Kotakt 60 sounds very good for certain situations but you know lemon juice or vinegar is also very effective if your able to wash the residue away anyway
Deoxit F5 is similar to Kontakt WL being both a cleaner and a lubricant at the same time, while D5/Kontakt 60 are just cleaners. As far as switches and potentiometers go, a cleaner is sufficient. Would rather do multiple cleans than use lubricant. Lubricant would only use if the pot/switch is disassembled and cleaned manually first. Not sure where you have read this, but Kontakt 60 is NOT an agressive acid like vinegar or lemon juice. I (and others) have been using this cleaner myself for many years (including for switches like in GX707) and can tell it doesn't eat away at anything, it just dissolves oxidation/corrosion. It does evaporate, that's why sometimes multiple cleans are needed if the switch/pot hasn't been used enough when the cleaner was sprayed.
Been using Kontakt 60 for years, my fav cleaner, never had any issues with 'eating' away at metal...pretty stupid to make a cleaner that destroys metal bodies of switches...duh
My appologizes if Im wrong I only did very light research on this on google and read the google overview. See below. From your and Black Fingers experience it sounds like it evaporates fairly quickly so it shouldnt be a problem. Sorry to Kontakt company for incorrect information above. I did also read somewhere that the acid sits on the bear metal forever - it must be wrong info Ok okay. Thats good to know. I read online that using a cleaner without the lubricant will actually break down any of the factory instealled lubricant on the potentiometer and now the metal on metal contact will increase the magnitude of wear each time its used. But to open a potentiometer is usually a time consuming job and can only be done so many times before breaking the folded metal that hold them in place. It does make me want to go the most basic spray of deoxidising cleaner route as its also a less risky procedure
