Sharp Twin Famicom AN-505 Repair Log

[flyingducky]

I have tryed both methods now with no sucess i'm thinking know that the disks I got my be the problem. both disk drives i got had broken belts when i got them and the disks I got from a thrift store were un tested.  I can get the error messages to change from 21, 22 to 27 and one of the disks go to a black screen before it give me an error message but thats as far as i can get. I heard from one site that the disks erase themselves over time or go corrupt is this true?

[madman]

Chimy, yea, I've only done it on 3 drives so I'm by no means a seasoned expert.  That's just what has worked for me to salvage the drives.  It even worked to bring one drive back from the dead that I thought had a bum belt.  It worked on one that loaded 50% of the disks I have, but it now loads them all perfectly. 

Ducky, if you get consistent 21/22 errors or consistent 27 errors across all disks, I doubt it's the disks.  Did you replace them with brand new belts?  Also, the drive speed could be off, that will cause errors as well.  I found that when I swapped belts between drives, or put in different belts, I'd often need to adjust the speed accordingly.  I have one drive that uses a non-OEM belt and it required tuning of the motor speed.  You may want to try Chimy's method.  If you want, I'd be happy to take a look at your drive and a disk or two and see if I can get it up and working for you.

[Nickv]

Yo guy are the best!!
Im at my girlfriends tonight but when i get home tomorrow im going to get straight to work on my fds. I Hope all goes well. Does anyone know of anywhere to get these hard to find game doctors. Im thinking here in canada its near impossible. Im going to go to what we call "the chinese mall" out in a area of toronto where the chinese population is masive. I go garage saling in those area's during the summer and always find super famicom stuff. Hopefully i can find someone with some original famicom stuff. Anyways thanks again everyone!!!!!!!

[Doc]

Thanks for the pictures and explanations, Chimy. I'm sure there's room on the site SOMEWHERE to put them in.

[JC]

I'll work on it. Very busy packing and moving, though.

[madman]

Nick, I can get game doctors, I'd be willing to trade them for other cool stuff or sell them at my cost from my guy in HK.

[Rockard]

I bought 10 cheap broken famicom disk system from yahoo japan some time ago, and just now got some free time to try to fix them. (planning to sell them locally)
I have fixed many broken disk systems before, usually just replacing the belt, but now I got some problems =(.

The belts I use are close to what they need, but not perfect. Sometimes they slide off if I screw around with them too much.. =(
Anyone know where I can get belts suited for fds at a good price?

Madman, you have access to game doctors? how much does these cost?

[Nickv]

How much do you want for the game doctors madman? Also Rockard  i bought a few belts from jfgoods on ebay a while ago. he didn't really give me a deal (bout 10 bucks a belt) but then again i didn't really try bargaining with them. Since i replaced it its never came off. the seller boasts there Nintendo ones.

[Rockard]

Also, is there any way to know if the drive has speed problems, or if it is the head that needs adjustment?
If I dont have any kind of indication of which, how do I know that the speed is correct before trying (in vain) to adjust the head?

Right know, I successfully got fooled by the jfgoods site and screwed around with the head totally.
I should have just replaced the belt without mocking with it to start with, I think.. ;(.
OR maybe I just didn't understand his method of fixing it completely.

Anyway, I have belts that are a bit to small, but they have a perfect fit otherwise. I guess I need to adjust the speed for them..

Using the speed-adjustment-screw, which way should I screw to make the motor go slower?
Since this belt I am going to use is a bit smaller than the perfect ones (I have an original belt that I measure alongside the other one),
I guess slower is the way to go.

[Nickv]

i Screwed around with it last night for a good 1 and  a half. The system ran a few games after i originally replaced the belt. So i know it has it in it. I just gata get it going. So far lately its been giving me just 22 errors. no more 27's. It also sometimes does the black screen for a bit like duckys but not lately. SO just to confirm i can adjust the head, the speed of the motor and the hight of the spindle. I was wondering how much contact the head so have with the disk. I think if i lower the spindle it might work. I will give it  a shot tonight.

[chimyfolkbutter]

Good point on the spindle.  One thing I have observed was the deterioation of the pressure pad on the arm .  This arm pushes the disk to the head.  When the pressure pad wears down, it doesn't apply the proper pressure on the disk. As a result, the head cannot read the data. 

In one case where I restored an FDS, I had to replace the pad with one I cut-out from an old cassette tape.  Once I did that, the FDS worked great. 

The presure pad is one thing to consider  when you are trouble shooting your disk.

-CFB

[madman]

I'm currently working on sourcing proper belts.  I've tried about 5 different types, all with failed results.  My guy in HK can get ones that work for ~$3.50/ea, but I'd like to find a cheaper US source.  Jfgoods is overpriced, but there's no other way to source official ones unless you use Yahoo Japan, but by the time you pay the shipping costs both ways and commission, you'd be better off w/JF. 

I'll have to check prices on Game Doctors, they are pretty common in HK.  I have a TGD6+ on the way to me, but can't recall the price offhand.

For motor speed, I can't recall off the top of my head, but if you turn it all the way to one way, boot it, turn it all the way to the other way, boot it...you'll hear a distinct difference in speeds and know which way is faster and which is slower. 

As for knowing what your problem is, if it's a belt, spindle, head or motor...there's no real way.  With a new belt you can obviously rule out a belt issue.  If you have a game doctor and copy util, you can properly tune your motor speed.  If your FDS reads some disks, but not others, it's a good sign you have a spindle or head issue.

[Nickv]

I noticed that pad was a bit destroyed. Looks like i finally have a use for those extra tape decks!

[JC]

TGD6+

A quick explanation of what this does?

[chimyfolkbutter]

TGD6 stands for (Venus) Turbo Game Doctor 6M - it plays pirate disks.   In the context of the post, using this in conjunction with Bung CopyMaster utility, a technician can calibrate the speed of FDS motor.

-CFB