ok, a growing problem with 1010 decks is an issue which involves the deck not 'communicating' with the computer. you can hear the cassette audio, but the atari doesnt recognise it. so you just hear the sound and get no actual loading. ive tried: recapping, brand new op amp chip, changed r138. ive done a few transistors but not as yet in the data line.
maybe when ive finished replacing them all it will help, but until then, anybody aware of this problem and if so how did you cure it? ive got decks with same problem before working by recapping so maybe theres a few different possible issues.
Well, there is no magic piece of advice that will cure the problem.
I would dismiss some obvious malfunctions (such as broken DATA IN wire, or faulty SIO port - can be checked with multimeter), but that's what you have done already.
Then you have no choice but to trace the signal from the head to the output transistor through all of the circuitry (that's tedious work) This is best done with oscilloscope, but even a multimeter will tell you if there is some signal or not. Tracing is probably better than replacing parts randomly.
Obvious checkpoints are the inputs and outputs of the integrated circuits and the output transistor (Q3). Just follow the schematic in the 1010's field service manual and ICs datasheets.
Of course you need to be doing this when the data recorder is dismantled, but still connected to a computer and the computer is reading data from the data recorder (POKE 54018,52). In these cases, good source of signal is a cassette adapter, because it will feed the reading head with signal even when you are forced to disconnect the motor.
This advice is vague at best, but what you can do when you are 1000 miles far away :-)
thanks baktra, the service manual has given some helpful advice, testing it when its dismembered is like you say awkward at best. my idea tho is to replace all the transistors and maybe i will have to replace the mylars as well.
i always think, especially with old old capacitors you may as well do the lot as its a false economy not to. a lot of the old ones i take out are stretched, leaking and positively knackered.
and as its not expensive i will replace all the transistors instead of just the one. saves any future problems.
i will get it working eventually, and when i do it will be something learned and in the future i will be ready for any similar faults on other devices.
i fixed so much stuff now ive lost count. most of it is common sense, but on the odd occasion i get a challange and i enjoy it. as ive said before its all a learning curve and im always willing to listen to advice, thats how i become more proficient.
upto now tho i have found most things are fixed by replacing the electrolytics, or diodes.