Atari 410 service manual test points / repair

[eizner23]

I am trying to service my 410 cassette drive. Made in Taiwan. Put in new belts, FF and rewind work. Following test points in the service manual, trying to confirm the health of the two ICs, one CA3046 transistor array and other the LM324N opamp, while I have it open.

 

With the unit plugged in, with no tape, play engaged, not hooked up to my 400 computer, should I be seeing measurements on the pins of the ICs? Schematic shows +5V test point next to R130, i have nothing. Tried engaging S101 as well. Not getting any readings in static mode either.

 

I am using pin 4 of IO cable as ground reference. i soldered a wire to that pad so I can clip to ground with VMM.

 

got nothing on V+ of the opamp.

 

Do I need a cassette in to get test point readings? Any advise would be appreciated.

[eizner23]

Still grinding away at this.

 

Realized its powered by the Atari that is why i saw no voltage readings plugged in by itself.

 

I did get it to play an audio tape but the supply wheel struggled to move, started eating tapes. I had to set it to FF for a few minutes to let it warm up before the supply wheel moved consistently without eating tape. Audio playback had a lot of noise but sounded ok. Got errors loading Frogger and Zaxxon on CLOADS.

 

Cleaned the heads but didnt demagnetize yet.

While I had it on the bench i changed out all the 5% carbon comp resistors to 1% metal film to try to eliminate some noise. Replaced as many film caps I could to WIMA films. That didnt do much help.

I am now going over tips from Antic magazine Tape Topics column found here https://www.atarimagazines.com/v2n1/tapetopics.html

I see suggestions for checking the IC and a few didoes in that article.

[adam1977]

I can't help, but good luck with the repair

[+kheller2]

Still grinding away at this.

 

Realized its powered by the Atari that is why i saw no voltage readings plugged in by itself.

 

I did get it to play an audio tape but the supply wheel struggled to move, started eating tapes. I had to set it to FF for a few minutes to let it warm up before the supply wheel moved consistently without eating tape. Audio playback had a lot of noise but sounded ok.

 

 

Do you mean the take-up reel? The pinch roller and capstan pull the tape over the head, the take up real is driven to take up the slack. If its eating tapes, the rollers are sticky or the take up isn't fast enough.

[_The Doctor__]

capstan or pinch roller could be binding, time for a tear down clean and lube. other choices wrong size belt...

[+Nezgar]

I did get it to play an audio tape but the supply wheel struggled to move, started eating tapes. I had to set it to FF for a few minutes to let it warm up before the supply wheel moved consistently without eating tape. Audio playback had a lot of noise but sounded ok. Got errors loading Frogger and Zaxxon on CLOADS.

 

CLOAD is for loading BASIC programs. To load binary programs like Frogger or Zaxxon, turn on the computer holding OPTION+START. At the beep, press PLAY and finally press return on the computer.

[eizner23]

The belts I got from a recommendation from this site, a person in Poland I believe.

Kit came with 3, but there was a small 4th belt i had to come up with, cant recall what it drove.

 

One of the rubber rollers had a dent in it from sitting pressed in same position for so long.

 

I might have been referring to the take up wheel, it's the reel on the right that doesn't spin much until the unit is warmed up. The mechanism needs more attention. Doctor is probably right fresh grease is in order.

 

I did make some progress, I recorded a basic program to a new cassette and cload the program with no issues. The audio signal sounded much more strong and clear while I noticed no noise like I did with frogger.

 

Maybe my cassettes are bad? Dont know how they were stored. I downloaded a few .cas files and will record them to fresh tapes.

[eizner23]

"CLOAD is for loading BASIC programs. To load binary programs like Frogger or Zaxxon, turn on the computer holding OPTION+START. At the beep, press PLAY and finally press return on the computer."

 

Thanks for that info. I got "boot error" trying to load those two games.

[+kheller2]

"CLOAD is for loading BASIC programs. To load binary programs like Frogger or Zaxxon, turn on the computer holding OPTION+START. At the beep, press PLAY and finally press return on the computer."

 

Thanks for that info. I got "boot error" trying to load those two games.

 

 

Are you trying this on the 400 and the 400 has enough memory for those games?

Another trick is to manually spin the tape until the leader / tape transition, then put that in and boot.

[TGB1718]

I have an old 410 Cassette, there were a few variants, like you I ordered a set of belts, Seller assured me they would fit, but they didn't.

Mine I think was a really old version which took it's power from a small jack on the side of the A800 power supply.

 

Still need belts.

[eizner23]

 

 

Are you trying this on the 400 and the 400 has enough memory for those games?

Another trick is to manually spin the tape until the leader / tape transition, then put that in and boot.

 

Its a 400 with 16K. I know one of the games is labeled 16KB. I did try to spin the tapes out to the leader and boot.

 

All the belts are fairly snug. Since the deck works after it has warmed up, it may be the old grease that has hardened/degraded.

[eizner23]

After previously being successful saving and loading a BASIC program to/from a new cassette, I proceeded to download some know good 16K .cas files, convert to .wav then record onto the same cassette.

No success here, I was still getting the same boot errors, even after trying to advance the cassette slightly to adjust when the header was being read. It seems sometimes it was reading more blocks of data than other attempts.

 

It appears the Atari console might be having issues reading the header on the CAS tape via FSK, but not the BASIC tape. I am curious if the Atari is having trouble disseminating the chunks of data in the header of game tapes, if the baud is different between loading BASIC and CAS files, or if CLOAD uses a different header arrangement.

 

Im reading All_about_Cassette_Tapes on Atartimania, page six mentions lower baud rate will affect the tolerance for the tape speed variation. While playing audio cassette I do think this unit experiences slight wow and flutter but why would the BASIC CSAVE/CLOAD work?

 

When I find one I am going to try a cassette adapter and loading a game over that from a laptop.