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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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I posted this at the Yahoo reeltoreel group, but no answers so far, so I
thought I'd try here. Just picked up my first reel to reel- an Akai GX-266D. It's in very good cosmetic condition, but the transport doesn't work, at least not properly. While the capstan motor(?)appears to be working fine, pressing the play or fast-forward/reverse buttons does nothing. I can get the motors to turn the reels by manually engaging the solenoid(s), so I know the motors work. Probing the relay coil I see that there is no signal to the relays when pressing any of the buttons. Actually, I measure 24VDC on one of the relay coils, but when pressing transport buttons neither side goes to ground as I would expect. I found a dead transistor (TR4: D361 90V NPN), and replacing it yielded a temporary semi-functional response. IOW, one of the play LEDs was lit upon power-up, and pressing the play button actually resulted in reel rotation! Unfortunately, it stopped working whenI pressed the stop button, and I couldn't get it to work again until I touched up the solder joints on the replaced transistor. After that it temporarily worked again for a few button presses, then quit. Any advice (or a schematic!) would be greatly appreciated. Thanks, Sam Lloyd |
#2
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Can't say if this relates to yours, but many old Akai's required a dummy
plug or a remote control be plugged into that octal plug at the rear. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Sam Lloyd" wrote in message ... I posted this at the Yahoo reeltoreel group, but no answers so far, so I thought I'd try here. Just picked up my first reel to reel- an Akai GX-266D. It's in very good cosmetic condition, but the transport doesn't work, at least not properly. While the capstan motor(?)appears to be working fine, pressing the play or fast-forward/reverse buttons does nothing. I can get the motors to turn the reels by manually engaging the solenoid(s), so I know the motors work. Probing the relay coil I see that there is no signal to the relays when pressing any of the buttons. Actually, I measure 24VDC on one of the relay coils, but when pressing transport buttons neither side goes to ground as I would expect. I found a dead transistor (TR4: D361 90V NPN), and replacing it yielded a temporary semi-functional response. IOW, one of the play LEDs was lit upon power-up, and pressing the play button actually resulted in reel rotation! Unfortunately, it stopped working whenI pressed the stop button, and I couldn't get it to work again until I touched up the solder joints on the replaced transistor. After that it temporarily worked again for a few button presses, then quit. Any advice (or a schematic!) would be greatly appreciated. Thanks, Sam Lloyd |
#3
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Mark,
Thanks for the reply. Mine doesn't have the remote jack, so that can't be it, unfortunately. Sam Mark D. Zacharias wrote: Can't say if this relates to yours, but many old Akai's required a dummy plug or a remote control be plugged into that octal plug at the rear. Mark Z. |
#4
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Mark,
Thanks for the reply. Mine doesn't have the remote jack, so that can't be it, unfortunately. Sam Mark D. Zacharias wrote: Can't say if this relates to yours, but many old Akai's required a dummy plug or a remote control be plugged into that octal plug at the rear. Mark Z. |
#5
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Can't say if this relates to yours, but many old Akai's required a dummy
plug or a remote control be plugged into that octal plug at the rear. Mark Z. -- Please reply only to Group. I regret this is necessary. Viruses and spam have rendered my regular e-mail address useless. "Sam Lloyd" wrote in message ... I posted this at the Yahoo reeltoreel group, but no answers so far, so I thought I'd try here. Just picked up my first reel to reel- an Akai GX-266D. It's in very good cosmetic condition, but the transport doesn't work, at least not properly. While the capstan motor(?)appears to be working fine, pressing the play or fast-forward/reverse buttons does nothing. I can get the motors to turn the reels by manually engaging the solenoid(s), so I know the motors work. Probing the relay coil I see that there is no signal to the relays when pressing any of the buttons. Actually, I measure 24VDC on one of the relay coils, but when pressing transport buttons neither side goes to ground as I would expect. I found a dead transistor (TR4: D361 90V NPN), and replacing it yielded a temporary semi-functional response. IOW, one of the play LEDs was lit upon power-up, and pressing the play button actually resulted in reel rotation! Unfortunately, it stopped working whenI pressed the stop button, and I couldn't get it to work again until I touched up the solder joints on the replaced transistor. After that it temporarily worked again for a few button presses, then quit. Any advice (or a schematic!) would be greatly appreciated. Thanks, Sam Lloyd |
#6
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"Sam Lloyd" wrote in message
... I posted this at the Yahoo reeltoreel group, but no answers so far, so I thought I'd try here. Just picked up my first reel to reel- an Akai GX-266D. It's in very good cosmetic condition, but the transport doesn't work, at least not properly. While the capstan motor(?)appears to be working fine, pressing the play or fast-forward/reverse buttons does nothing. I can get the motors to turn the reels by manually engaging the solenoid(s), so I know the motors work. Probing the relay coil I see that there is no signal to the relays when pressing any of the buttons. Actually, I measure 24VDC on one of the relay coils, but when pressing transport buttons neither side goes to ground as I would expect. I found a dead transistor (TR4: D361 90V NPN), and replacing it yielded a temporary semi-functional response. IOW, one of the play LEDs was lit upon power-up, and pressing the play button actually resulted in reel rotation! Unfortunately, it stopped working whenI pressed the stop button, and I couldn't get it to work again until I touched up the solder joints on the replaced transistor. After that it temporarily worked again for a few button presses, then quit. Any advice (or a schematic!) would be greatly appreciated. Thanks, Sam Lloyd I've never seen the model you have, but I used to own a model X-255D reel-to-reel deck, which may be close to yours in design.. Intermittent relay contacts were a constant source of problem, as were the PCB receptacles that interfaced with all of the circuit boards in the unit. The receptacles spread apart on the sides, resulting in very intermittent contact with the PCB contacts. After many years, I finally got tired of disassembling that monster and trashed it. Cheers!!! -- Dave M Good judgement comes from experience, and a lot of that comes from bad judgement. |
#7
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Thanks, Dave. It turned out to be a few bad transistors and diodes.
Actually, it's still not working quite right- the tape won't change directions properly- it will play fine in one direction, but I have to cycle power for it to play in the opposite direction. It's quite possible that this a relay problem, although I haven't quite deciphered all the details of what's involved in changing direction. Thanks, Sam Tweetldee wrote: "Sam Lloyd" wrote in message ... I posted this at the Yahoo reeltoreel group, but no answers so far, so I thought I'd try here. Just picked up my first reel to reel- an Akai GX-266D. It's in very good cosmetic condition, but the transport doesn't work, at least not properly. While the capstan motor(?)appears to be working fine, pressing the play or fast-forward/reverse buttons does nothing. I can get the motors to turn the reels by manually engaging the solenoid(s), so I know the motors work. Probing the relay coil I see that there is no signal to the relays when pressing any of the buttons. Actually, I measure 24VDC on one of the relay coils, but when pressing transport buttons neither side goes to ground as I would expect. I found a dead transistor (TR4: D361 90V NPN), and replacing it yielded a temporary semi-functional response. IOW, one of the play LEDs was lit upon power-up, and pressing the play button actually resulted in reel rotation! Unfortunately, it stopped working whenI pressed the stop button, and I couldn't get it to work again until I touched up the solder joints on the replaced transistor. After that it temporarily worked again for a few button presses, then quit. Any advice (or a schematic!) would be greatly appreciated. Thanks, Sam Lloyd I've never seen the model you have, but I used to own a model X-255D reel-to-reel deck, which may be close to yours in design.. Intermittent relay contacts were a constant source of problem, as were the PCB receptacles that interfaced with all of the circuit boards in the unit. The receptacles spread apart on the sides, resulting in very intermittent contact with the PCB contacts. After many years, I finally got tired of disassembling that monster and trashed it. Cheers!!! |
#8
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"Sam Lloyd" wrote in message
... I posted this at the Yahoo reeltoreel group, but no answers so far, so I thought I'd try here. Just picked up my first reel to reel- an Akai GX-266D. It's in very good cosmetic condition, but the transport doesn't work, at least not properly. While the capstan motor(?)appears to be working fine, pressing the play or fast-forward/reverse buttons does nothing. I can get the motors to turn the reels by manually engaging the solenoid(s), so I know the motors work. Probing the relay coil I see that there is no signal to the relays when pressing any of the buttons. Actually, I measure 24VDC on one of the relay coils, but when pressing transport buttons neither side goes to ground as I would expect. I found a dead transistor (TR4: D361 90V NPN), and replacing it yielded a temporary semi-functional response. IOW, one of the play LEDs was lit upon power-up, and pressing the play button actually resulted in reel rotation! Unfortunately, it stopped working whenI pressed the stop button, and I couldn't get it to work again until I touched up the solder joints on the replaced transistor. After that it temporarily worked again for a few button presses, then quit. Any advice (or a schematic!) would be greatly appreciated. Thanks, Sam Lloyd I've never seen the model you have, but I used to own a model X-255D reel-to-reel deck, which may be close to yours in design.. Intermittent relay contacts were a constant source of problem, as were the PCB receptacles that interfaced with all of the circuit boards in the unit. The receptacles spread apart on the sides, resulting in very intermittent contact with the PCB contacts. After many years, I finally got tired of disassembling that monster and trashed it. Cheers!!! -- Dave M Good judgement comes from experience, and a lot of that comes from bad judgement. |
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