UH! OH! fostex B16 rewinds really weak, then slows to a stop

[whitestoneaudio]

What could that be. Im looking for the service manual now. Was stored by a relative and found out it was stored in a damp basement. I spent alot of time cleaning it up and making sure everything worked. I used it to go through a couple of tapes and all of the sudden the rewind reel isnt engaging strong. when i hit play there is no tension on it. Seems like something isnt engaging or engaging strong. Im no slouch in the electronics department but i need to find a starting point. Any info on where to go from here would be greatly appreciated. thanks guys.

[whitestoneaudio]

Im new to this forum thing still.

[Snarl 12/8]

It sounds a lot like my fostex 8-track after somebody poured water through it. I'm kinda curious what people think could be done to fix it. I'm wondering though, is there any chance it could be the tape? I always assumed this problem was my tape and not the mixer, because, crazily enough the tape deck seemed to work fine for a while after the water incident, but then this started happening with my tapes, which are 10-15 years old and also stored in a damp basement. Could it just be that your tape is clogging up the works, or do you definitely feel like it's a power problem in your deck?

[whitestoneaudio]

Hmmmmm.... Could be. I dont have any new tape to try this theory out on though. Im waiting for an old motu 2408 to be shipped. My 828 blew. I need to transfer all these tapes to try to save the audio from them. Ill buy a new half inch reel to try it out though. I know the tapes have to be hurtin even though they are only 5 years old. I found them in a sealed box in the garage from 3 years ago when i moved here. Im in ohio and i know it was damp. i dont have garage doors. I did email the guy from nashville that calibrates tapes to see if he had any input on what to do. im ready to throw it out the window and get a tascam 48 a guy up here is selling but i need to get the audio off my reels first. I wish digital sounded as good. Reel to reel = work.

[whitestoneaudio]

Could also be that the moisture caused oxidation or something like that in the motors. Same thing. It worked for a while then just stopped. Could be that the moisture gunked up the solenoids and inner mechanical working that engage and disengage the motor and brake. I hope its fixable thats all. Im broke right now and everything needs fixed.

[whitestoneaudio]

Weird update. I just fired it back up, pushed the rewind button and it worked no problem strong. played a bit, rewinded a few times and it starts all over again, getting weaker and weaker.

[skywavebe]

Hi Whitestone,
Tape decks from Japan are kind of similar. In fact the Teac Manager who hired me in the good old days to work at Teac now works at Fostex.
Moisture in my experience has never caused the failure of a motor but might make the exterior oxidize depending on finish. The issues you are experiencing are intermittent and thus I would have a look at the power supply board and look for broken or thermal caused breaks in some solder joints that supply the reel motor voltages. Stick tape can be an issue but you would kind of notice that right away and it would be constant. I commonly look at power boards in Tascam and Teac units to find many joints that I do not like and resolder them. Other Teac Techs used to say my units go out a pound heavier but they did not come back. Wave soldering is known for applying a minimum of solder to the component joint and when a given large wattage part like a current limit resistor in a power supply or regulator heat and cool a couple hundred times that allows the poor solder joint to become broken due to thermal expansion and contraction. Resolder it and it is fixed.
It could also be filled stator on the motor but then that would be constant and not on/off. Chances you have bad soldering on a board.

[whitestoneaudio]

thanks for that info. im gonna take a look at it. I would like to find the service manual also. Just as a back up.

[whitestoneaudio]

thanks for that info. im gonna take a look at it. I would like to find the service manual also. Just as a back up.

[blackdiscoball]

Well just in case you were even halfway serious don't just pitch it out the window! Im in Ohio and would take it off your hands broken or not.

[jshirks]

I would say clean ALL of the tape path THOROUGHLY, throw that tape away and get a new one.

I recently stumbled onto a free Calibration tape, I figured I would give it a whirl. Without any symptoms or warnings my perfectly running machine goes into low go. Fast forward crawls to a start and only goes 1/4 of the speed. Play is pitiful. There wasn't any obvious shedding, no smoke, I had no idea. Took the tape of and the path looked like it had been trampled through the mud. It happened within 2 mins of running this reel. Cleaned it up, fresh tape. Good as new.

Obviously if the tape path isn't clearly clogged this may not be your issue, at least try a different tape (I didn't notice until I took the tape off.) Check voltages to the reel motors with and without load. Check the brake tension, maybe the brakes are dragging. Is the capstan slipping? Hopefully it is something simple, good luck.

[Chaconne]

This sounds like perhaps a clutch problem. Sometimes there are felt pads in the reel base assembly that just deterioate in time meaning that there is no give anymore in the opposite direction so things just get to tight and wind down. If there was no clutch, any problems from the supply reel or anywere along the tape path that introduced any drag would result in the tape tighening as the take up reel continued to spin. If the clutch was to slippy, the the winding would be to loose - so the tension has to be right.

What I have said may be complete bull of course, but I had a machine that did just that and after taking apart the take up reel spindle it was obvious that it was almost completly siezed up and would not respond to any pull in the opposite direction. after sorting this out - worked like a dream. You will need a service manual and the confidence to pull things apart of course! Search online and you might find one - although people are making money out of selling PDF's of these things.

[supafuzz]

Is it possible that your tape is sticky and needs to be baked??