Help please! Stuck on repair due to stripped bolt head...

Taketheflame

Super Member
Hey all,

In the middle of trying to change the belts on my Akai GX-F80 (seller claimed it was "turn key", but it isn't working properly - the old belts are worn for starters), and unforuntately, I've come across one of the worst situations possible with disassembly....

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That bolt just above/to the right of the right reel? (that holds the backing plate in place). Whoever took this thing apart last time stripped the bolt head (thankfully the other bolt that's already removed is ok and I was able to get another one). I've tried the following to get it out...

- Using various substances (paper towel, duct tape, etc.) between the bolt head and screwdriver for additional grip/filling the space).
- Needle nosed pilers on the head w/material for help w/grip.
- Using a serrated drill bit designed for removing stripped head bolts.
- Sticking a screwdriver w/liquid nails in the bolt head and letting it set.

None of these have worked. Obviously, this isn't a scenario where the blunt force methods (heat, hammers, etc. are really applicable, as I certainly don't want to destroy the plate/damage the deck to get it out...

Anybody got any ideas? I'm pretty close to giving up and having a tech remove it..(don't want to keep making multiple hardware store trips and blowing money on tools that don't/won't work).
 
Cover, seal the whole area with tape and plastic leaving just the head exposed. Then with a dremel type tool with a cut off wheel. Cut a slot into the head allowing you to then loosen with a slotted screw driver.
 
Do the above operation with the deck upside down so none of the metal filings end up in the head area or slide plate mechanism. Maybe put a large fridge magnet under to catch the filings.
 
A small set of Vise-grips can work. Set them so they lock on the screw head. If it's a round-head screw, the slot method suggested above is a good way to go. Demag the tape path after, though. The Dremel motor may magnetize stuff in it's EM field.
 
And if that doesn't work just drill the head off and remove the stub with vice grips. It probably isn't corroded in place, you just can't get enough purchase on it to break it free.

See also, the recent thread about JIS screwdrivers. Yes I know you didn't do the damage on this one, but still.
 
Hopefully it's just the head socket that's stripped. Bad news would be if the driver socket is stripped because the bolt was installed cross-threaded, or SAE instead of metric replacement. The vice-grips suggestion, from the side, super tight, with a protective plastic layer over the metalwork is the approach I'd take. Wiggle both directions to help get it turning. Making chips would be a distant second choice in a tape deck.
 
Vampliers. The best thing for removing stubborn Japanese screws.
Thanks for the suggestion - found and ordered a smaller pair of these specificially designed for small bolts/electronics work, so I'm hoping for the best!

The dremel/cutting a slit in the head is method is the last resort - mainly because I don't want to accidentally miss and hack up the backing plate, and I don't think the neighbors will like loud grinding sounds, as brief as they may be, lol
 
Usually a diagonal cutters will bite into the sides of the screw head enough to crack it loose. Then it is easily remove-able.
 
a SMALL amount of 'rust-bust' applied before some heat (soldier pencil, etc), then with a proper size/type screwdriver held tightly to the head, tap on the screwdriver end REPEATEDLY in a light manner while applying SLIGHT twist. I've tapped for over 2 minutes on some thing or another and this method works for me 99% of the time.
A method I learned working as a SAAB/VOLVO tech many many yrs ago. YMMV

I've also used a spring loaded automatic center punch around the edges but this case has too much potential to damage the backing plate.
 
So - the good news - some Vampliers made very short work of the stubborn bolt, and the new belts are on!

But...I've come across a possible big pitfall - I noticed what I'm worried might be tape head damage...

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Notice the white-ish streak marks in the center of the head assembly immediately outside of the tape path. I've tried getting it out by cleaning w/a Q-tip and 91% alcohol, but it isn't going away. I'm told that the GX heads should be all shiny black-ish silver like the rest of the head (which you can even see reflections off of).

Funny thing is, when I played tapes on it, the little bit of play time (a few minutes) where the deck worked sounded even better to me than my standard GX head decks (such as a GXC-760D) w/no blemishes on the heads...

Is it possibly stubborn dirt/tape gunk? Seller claimed the deck was cleaned in the ad, but I wiped a fair bit of dirt off the capstan, so they either didn't do a good job, or might be full of it.

Just wanna know before I proceed any further - it's not too late to get a "not as described" refund on it if worse comes to worse, as much as I want to keep this deck (I'd imagine spare heads are hell to source...).
 
I can't tell anything from that picture. Can you post a high res photo taken with a real camera set to macro mode, with the flash on?
 
I think I see what you are talking about. It's not in the tape path, and you said it sounded good. I wouldn't worry about it
 
dr*audio - I actually only have a phone camera at the moment, but I've attempted to highlight/zoom in a bit on the area in question (inside of the green circle).

tapehead.jpg

Another theory I have is that it may be a scratch from a demagnetizing wand. In any case, with a light touch w/my finger, it doesn't feel rough, or different from the rest of the center of the tape head.
 
Ok, I'm back!

So - while the deck was still partially disassembled, I put in a tape to see if belts fixed playback issues - they did not - although I did notice that the main drive belt assembly seemed to be spinning smoother.

Here's what's going on - all the buttons on the deck function as they should, but with playback, the tape speed is slower than it should be, and it gradually slows down until the deck stops the tape. I made a short video of the deck doing this before the belt change for observation (although I stop the deck when the tape stops in the video).


I'm beginning to suspect a faulty idler tire? Unfortunately, I'm not sure where to get a replacement if that's the case...
 
Someone here on AK retreads tires, or maybe the guy is not a member here but the service has been mentioned here.

Anybody remember that?
 
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