Franco989
Member
I'll try cleaning these switches also, I haven't tried recording yet since I only have one tape at the moment that I'm using for test. I'll see if I can get a hold of another one.
Pioneer RT-701 playing to fast
- Thread starter Franco989
- Start date
You don't need to have the two record safety switches enabled to test the pitch control bypass function on the record button, you can leave them off and push record / play while a tape is playing. As long as both safeties are off (buttons in the out position) the oscillator won't power up and your tape won't be erased or recorded over.
When the speed acts up make sure the record safeties are not enabled and then hold the play button in while pushing in the record button. See if the speed problem is affected by engaging / disengaging the record button. If nothing changes it's probably the servo board connections, bad solder joint or a beat component on the servo board seeing as how you've already cleaned the speed selector and switchboard connector.
Double check the frequency generator reference signal cable connections. These are the small wires housed in the brown jacket at the end of the motor connector plug. It's similar to an audio cable, with a small center wire shielded by a bare wire in a jacket. Make sure the connections for those two pins are clean and tight. Without the FG reference signal the motor will run wild.
When the speed acts up make sure the record safeties are not enabled and then hold the play button in while pushing in the record button. See if the speed problem is affected by engaging / disengaging the record button. If nothing changes it's probably the servo board connections, bad solder joint or a beat component on the servo board seeing as how you've already cleaned the speed selector and switchboard connector.
Double check the frequency generator reference signal cable connections. These are the small wires housed in the brown jacket at the end of the motor connector plug. It's similar to an audio cable, with a small center wire shielded by a bare wire in a jacket. Make sure the connections for those two pins are clean and tight. Without the FG reference signal the motor will run wild.
Franco989
Member
Ok after cleaning the speed switch this morning and turning on the reel this evening it looks like it's back to working normally I don't want to say for sure this fixed my issue since I've run into this before I'll keep testing it through out the week and see if the issue arises again.
Franco989
Member
What should I clean it with?NEVER CLEAN A RUBBER PINCH ROLLER WITH ALCOHOL!
That's a NO NO
Warm water with mild soap added using a cue-tip works for me.Alcohol will make the rubber turn hard and prone to slippage.After using the soap method you can mildly rough the rubber with very fine sandpaper or emery cloth or paper if you like.Many threads on how to do this here if you search
Franco989
Member
Spoke too soon, problem came back. I'm taking of the servo and having a buddy of mine test the capacitors.
Franco989
Member
Thanks didn't know I was doing it wrong.Warm water with mild soap added using a cue-tip works for me.Alcohol will make the rubber turn hard and prone to slippage.After using the soap method you can mildly rough the rubber with very fine sandpaper or emery cloth or paper if you like.Many threads on how to do this here if you search
Franco989
Member
What's a good site to get capacitors from? I was just going to order a kit from Amazon with an assortment of values but I'm not sure of the quality. Speaking of quality, how do I determine good quality? Should I just go with the brand name's here?
QSilver
Super Member
The Nichicon's and Panasonics are generally good makes, though there are other good ones too. There are certain models of capacitors that both companies do that I and others here pick. I usually get things from Mouser. They have a good range and value. Electrolytics are polarised capacitors - they're the cylindrical ones. There are others and sometimes the eletrolyitcs that are around 3uF or lower can be changed out for film capacitors which are usually bi-polar - they can be put back in like you would a resistor. They often have a smaller accuracy tolerance and have a longer life than eletrolytics which have a life of approximately 20 years or 2000 hours of use. The hour rating varies a lot depending on the model of capacitor you buy. I hope that helps. 
Franco989
Member
Yes it does thank you for the explanation.The Nichicon's and Panasonics are generally good makes, though there are other good ones too. There are certain models of capacitors that both companies do that I and others here pick. I usually get things from Mouser. They have a good range and value. Electrolytics are polarised capacitors - they're the cylindrical ones. There are others and sometimes the eletrolyitcs that are around 3uF or lower can be changed out for film capacitors which are usually bi-polar - they can be put back in like you would a resistor. They often have a smaller accuracy tolerance and have a longer life than eletrolytics which have a life of approximately 20 years or 2000 hours of use. The hour rating varies a lot depending on the model of capacitor you buy. I hope that helps.
Franco989
Member
ok so after finally purchasing a soldering iron and getting my caps in this week I recapped the whole board this afternoon (BTW great learning experience had my neighbor teach me). The bad news is that the problem is still there 
, I resprayed all the switches and molex connectors with deoxit and left overnight hoping some miracle might happen. BTW I have attached a picture of the values I pulled off the board and the ones I purchased from Mouser if it helps anyone with recapping this board.
, I resprayed all the switches and molex connectors with deoxit and left overnight hoping some miracle might happen. BTW I have attached a picture of the values I pulled off the board and the ones I purchased from Mouser if it helps anyone with recapping this board. 
petehall347
the brandy coffee man
dont know if i mentioned this but i had someone call me on the phone to help with a R TO R playing fast . turned out the pitch control had been wired wrong .. i did however learn if the pitch control loses a connection the speed will run fast ..
not saying yours will be the same but worth a look ..
not saying yours will be the same but worth a look ..
I can almost say for sure that it is the Molex plug
On my 707 it gave me so much grief I must have sprayed it several times and still had the problem
It wasn't until I physically took the thing apart and cleaned every single contact by hand that my deck now runs perfect
As I was cleaning it all the contacts had a grime on them wich simply could not be removed by spraying Deoxit on them
I hope that helps
On my 707 it gave me so much grief I must have sprayed it several times and still had the problem
It wasn't until I physically took the thing apart and cleaned every single contact by hand that my deck now runs perfect
As I was cleaning it all the contacts had a grime on them wich simply could not be removed by spraying Deoxit on them
I hope that helps
petehall347
the brandy coffee man
yes clean the connections ..i dont generally repair reel to reel but have spent all day on a teak a-5300 that was sent me under protest .. damn thing was full of corroded edge connectors .
Franco989
Member
Good suggestion I'll give this a try this weekend.
Franco989
Member
yep will do.
Franco989
Member
Yes it does (atleast that is what I can tell it runs quite fast, but even before the cap replacement it would adjust the speed).