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Need help with SL 1700MK2

Both of mine have the infamous cracked gears, however in each case it has no bearing on their respective ailments. Actually, one of them functions perfectly despite it. :thmbsp:
 
Normb said:
Hmmm, no mention of the cracked plastic gear in the thread. Has that been overlooked?
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Hi there, welcome to AK, nothing has been overlooked, the gear shows some stress cracks, yes, but it is firmly held in place, last week I went through it again, cleaned every switch again, and still no cueing and no auto return, so for now it is in storage, awaiting a fix, or a donor unit.
 
I'm wondering, if you replaced the tone arm assembly with a 1200 tone arm, wouldn't you have cueing then? Aren't they the same essentially?
 
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They are pretty much the same, and trust me, I have thought of that :thmbsp: , But i was really looking forward the auto return.
 
Zodia said:
Hi there, welcome to AK, nothing has been overlooked, the gear shows some stress cracks, yes, but it is firmly held in place, last week I went through it again, cleaned every switch again, and still no cueing and no auto return, so for now it is in storage, awaiting a fix, or a donor unit.
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Have you had the small board that controls the automation checked?
 
Hi, no I haven't, not really sure where I should take it, I suppose I could try audiolab, just not sure if mike would accept just the board...may have to give him a call, as soon as I get my vehicle fixed.
 
Balifly said:
Would the tonearm assembly from the SL-1600MK2 work ?:scratch2:
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No the way the automation works is different plus the 1600MKII has a big chip on the main board that the 1700MKII doesn't have. That big chip from what I understand is NLA it's the only one i know that at this point for these tables is the only one that is NLA.
 
Looks like we have the same problem. I bought an SL-1700MK2 that was honestly sold as 'for repair' the belt was toast so I replaced it now the cuing works but no auto return (it will return if I click the cuing button twice.) The service manual is pretty bad for this part of the turntable - check optics. I would like to check them but what are they supposed to be doing? Seems like everything else has logic tables and test point values but not the arm control board. If the one IC is bad it is still available for about $5.
 
Micro Switch

One of these on mine is not right - several thousand ohms open and closed (removed from the tonearm.) Fortunately they are dirt common parts and bought 2 replacements from a local electronics surplus store for $0.89 ea. These are great fun to gain access to. The chips and transistors for the arm control board are all still available and cheap. I picked up one of the 4011 chips as it is mentioned as a possible cause in the service manual ($0.25)

scottrt said:
There is a little micro switch activated by hi and lo spots in that white disc the worm gear spins. If it is dirty or hanging, could cause the issues you are experiencing.

I would not suspect the motor unless you have tried putting 12v dc to it and it fails to spin.

Scott T.
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srbliss said:
One of these on mine is not right - several thousand ohms open and closed (removed from the tonearm.) Fortunately they are dirt common parts and bought 2 replacements from a local electronics surplus store for $0.89 ea. These are great fun to gain access to. The chips and transistors for the arm control board are all still available and cheap. I picked up one of the 4011 chips as it is mentioned as a possible cause in the service manual ($0.25)
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Hi, where are you sourcing those chips? I have a 1700MK2 with dead automation.
 
Chips

I got mine from Halted (Halted.com for those not local to the bay area.) Mouser also has them for $0.50 these are just CMOS quad and gates. Most of the chips on the logic board seem available as well, not all but most. I will keep looking and see if I can find sources for all. Maybe we can pool some $ and do a group buy as the shipping will be more than the parts. I also have a few accounts with obsolete parts brokers that are a pain to deal with for one or two parts.
Steve
 

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srbliss said:
I got mine from Halted (Halted.com for those not local to the bay area.) Mouser also has them for $0.50 these are just CMOS quad and gates. Most of the chips on the logic board seem available as well, not all but most. I will keep looking and see if I can find sources for all. Maybe we can pool some $ and do a group buy as the shipping will be more than the parts. I also have a few accounts with obsolete parts brokers that are a pain to deal with for one or two parts.
Steve
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Count me in:thmbsp::thmbsp:
 
Are you sure it's the board and not one of those micro switches? I have re-flowed the arm control board and replaced all of the electrolytic caps and still no joy. Like I mentioned I do seem to have a bad switch.
Sure would be great if we are able to re-name (and show how to do so) this thread to 'How to fix the auto return on the SL-1700MK2'!!!
 
srbliss said:
Are you sure it's the board and not one of those micro switches? I have re-flowed the arm control board and replaced all of the electrolytic caps and still no joy. Like I mentioned I do seem to have a bad switch.
Sure would be great if we are able to re-name (and show how to do so) this thread to 'How to fix the auto return on the SL-1700MK2'!!!
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I'm pretty sure it's the ICs. They actually failed back in the 80s, and a local shop was able to replace them to get it working again.
 
Yeah, IC's, it would be great to get my 1700 online, I have taken the all arm assembly apart tested every switch (mechanical and optical) and they are all good, there is just no power to the board (if memory serves me right) it is related to a bad IC.
I have been entertaining the idea of modding the TT for manual operation only, by getting a 1200 arm assembly, but if the IC's are still available getting the 1700 back to it's original form would be great.
Keep me posted.

John
 
How do you test the optical switches?

No info in the manual that I can find.

Zodia said:
Yeah, IC's, it would be great to get my 1700 online, I have taken the all arm assembly apart tested every switch (mechanical and optical) and they are all good, there is just no power to the board (if memory serves me right) it is related to a bad IC.
I have been entertaining the idea of modding the TT for manual operation only, by getting a 1200 arm assembly, but if the IC's are still available getting the 1700 back to it's original form would be great.
Keep me posted.

John
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Getting ready to place a parts order

Mouser has some of the transistors and the micro-switches. See the attachment for the price list. Unfortunately I can only find one source for the one transistor used all over the arm board (8 of them, 7 on the logic board) these are the ones suggested as possible problems in the service manual. The place I found charges $16 for shipping so I suggest placing a large order. If you would like to join me I will be happy to order the parts for you and ship them out at my costs. If you need any of the parts from the Mouser list I can add those too.
Steve
edit - I can get the IC for you as well I think they are 50 cents at Mouser or I can stop by the surplus place for 25 cents.
 

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