Pioneer RT 1020L

Discussion in 'Pioneer Audio' started by Shaun b, Nov 10, 2017.

  1. Shaun b

    Shaun b New Member

    Messages:
    38
    hello all, I recently got a new to me Pioneer 1020L RTR, my first. It is in great condition and the owner still had all original paperwork and box. Last night I started to make my first tape and after a couple songs, I decided to listen to the tape to see what it sounded like. It sounded great except it only played back through one speaker. I triple checked switches and tried again doing exactly what the book said. Same result. While it’s recording, I switched to tape play and the left side went out, switched back to source and it came back. I also noticed the left meter would sometimes “die” and in a second or two come back or if I hit the volume for left the meter would wake up again but never will it record to tape on left side. I comfortable getting inside the deck and looking around. I know what the components are and what the do and how to test. I’m much more comfortable with the electronics than the mechanics actually. Where should I start looking? I don’t see any obvious bulging caps or burned resistors and fuses all checked out. Anyone had this problem or know where I should start testing, I would appreciate it very much. Thanks in advance.

    Shaun
     
  2. audiojones

    audiojones Jonesin' for audio Subscriber

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    The 1020L is a great tape deck, congrats on getting one - you're off to a great start! I guess the first thing to determine is if it plays back a known good stereo tape recorded on another machine through both channels. Do you have any other tapes with stuff recorded on them to play back? If stereo recordings play back through both channels try recording over them to see if it erases both sides (assuming it's not a valuable recording that is).

    It would be a good idea to thoroughly clean all of the switches and volume controls with contact cleaner and exercise them vigorously, also clean the heads and the tape path really well with rubbing alcohol. Dirty controls and dirty heads can often cause these problems, especially on equipment that has been sitting idle for a long time.
     
  3. Shaun b

    Shaun b New Member

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    38
    It came with one 10 inch and it plays back through both speakers. I just got it back together and I did clean very well. I noticed while cleaning the middle head, not sure what function the middle head takes care of, that there is a section that looks like it’s scratched and missing the “film” covering the rest of the surface. It did sit in the previous owners closet wrapped in a garbage sack for over 10 years. And he was a smoker. I didn’t think I was ever going to get all the funk off but I did and with the 10 inch reels on, she looks beastly. I haven’t made a mix tape in 20 years lol I’m dying to get this thing going. Thanks for the reply and I’ll let you know what happens.
     
  4. pustelniakr

    pustelniakr Silver Miner at Large Super Mod Subscriber

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    Start by working each of the user controls 100 times each and see if any effect is noticed. Report back.

    Enjoy,
    Rich P
     
  5. Shaun b

    Shaun b New Member

    Messages:
    38
    sigh.... still not acting right. I did notice that if I’d turn the volume all the way down on the right channel I can hear the left faintly and muddy. I worked every knob and switch a couple hundred times but it didn’t fix it. I also noticed there is a big change in volume and clarity in the Chanel that is working when I switch it from source to play. I guess I’m taking it back to my shop and give the Controls another go. I guess that nicotine that coated the outside could have gotten in pots but I soaked them yesterday. Anyway it’s fun to do so if I go. Any more suggestions, I will be checking. Will report back
     
  6. audiojones

    audiojones Jonesin' for audio Subscriber

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    You might have to clean the heads a little more aggressively, like with a light aluminum polish on a Q-tip. Rub the polish onto the heads in a side to side motion only and clean any residue off thoroughly with alcohol. The middle head is the record head and there's not supposed to be any "film" covering it or any of the head contact surfaces, they should be shiny and clean. Your heads may have residue from someone using a "sticky shed" tape or just years of use with poor maintenance. Polish up and clean all of the tape guides too, anything the tape touches must be super clean and friction free.

    Left head is the erase head, middle head is the record head and the right head is a four track playback head (the 1020L can play back both standard 1/4 track stereo tapes as well as full 4 track single direction tapes). The erase head is the only one that should be dark in appearance due to the material it's made of but the tape contact surface should be very clean. Heads and guides should be spotless and clean, should look like this:

    Erase head on the far left, Record head in the center, 4 track playback head on the far right.
    [​IMG]
     
    Last edited: Nov 11, 2017
  7. pustelniakr

    pustelniakr Silver Miner at Large Super Mod Subscriber

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    6,632
    Location:
    Tucson, AZ
    You remember how folks used to smack the sides of their old TVs? Now, smack the deck while recording, and see if any interesting responses occur, and report back. Don't hit it hard, or knock it off the table. We are checking for vibration sensitivity, which could indicate intermittent solder joints or relay contacts.If the problem clears up, even for a brief moment, that is significant. We know a few circuits are working. Some others are not yet verified. Again, don't be too rough now. If there is a response, we may go in and gently tap in localized areas that may be involved.

    No. I don't do this every time, but where fruit may be born I do.

    Enjoy,
    Rich P
     
  8. Shaun b

    Shaun b New Member

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    38
    No change when I smacked it. So I suplexed it followed up with a Dusty Rhodes elbow and a Jimmy Superfly Snuka of the top turnbuckle. Didn’t phase it. I’m leaning towards the volume knob. I cleaned the pot itself several times with a generous amount of Deoxit but I think it’s in the shaft. If I turn both left and right at the same time it’s easy and smooth. If I hold the right side and just turn the left side it’s much “stickier”. It feels exactly like what I would think it would feel like if it were coated in nicotine. I have been working it for an hour and every now and then I get low sound coming through. Is the away to separate the 2 shafts for a better cleaning?
     
  9. pustelniakr

    pustelniakr Silver Miner at Large Super Mod Subscriber

    Messages:
    6,632
    Location:
    Tucson, AZ
    No, well yes, but it is invasive and maybe not re-assembleable. If you get enough DeOxit in there, it will solubize the original lube in the shaft and free it up quite a bit. You are approaching non-DIY activities, requiring test equipment. Got any? You will likely need an oscillocsope before long.

    Enjoy,
    Rich P
     
  10. audiojones

    audiojones Jonesin' for audio Subscriber

    Messages:
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    Location:
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    Before you go forward with electronic troubleshooting can you elaborate on the "film" you see covering the record head? Maybe you can provide a picture of the heads if possible to help clear this up. As I said there isn't supposed to be a film on the head surface so this has me wondering if your recording issue is simply a matter of filthy heads that need more aggressive cleaning.
     
    pustelniakr likes this.
  11. Shaun b

    Shaun b New Member

    Messages:
    38
    I took a closer look at heads and it was that something was scraped off, it was something stuck on. I have them looking like mirrors now. They literally look like brand new. Im about to start on the volume control again. There is a huge difference it the volume and mic controls when turning both. The mic feels like I would expect. The volume just takes more pressure. I will report back shortly. Thanks for everyone’s help. This site is great.
     

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