Hello All,
I am finally getting around to doing the "griplets" on my CD104 and a litte confused.
After unsoldering the griplets and inserting a metal piece in the vacated hole: Does the metal piece need to have contact with both boards, of just pass through the vacated hole on one board and soldered?
Does the question make sense?
Any help would be greatly appreciated.
thanks.
I am finally getting around to doing the "griplets" on my CD104 and a litte confused.
After unsoldering the griplets and inserting a metal piece in the vacated hole: Does the metal piece need to have contact with both boards, of just pass through the vacated hole on one board and soldered?
Does the question make sense?
Any help would be greatly appreciated.
thanks.
Yes, also the 304 (mkII) has often those faulty connections to both side of the gnd plane
Few months back i have gotten a 304 for free, broken, but knew of this problem. Soldered the griplets and it played again!
It plays now Non-OS on the attic-set, sounds very good (rock solid CDM1) and before i got allways listening fatigue with non-os, with the mother of all dacs TDA1540 it sounds very convincing for a only 14 bit machine! The 1540 is very fast you can hear that. Opamp is my favorite THS4032, and done some further mods as schottky's, better caps better decoupling (2 opamps had only 2 small caps with very long power lines)
Few months back i have gotten a 304 for free, broken, but knew of this problem. Soldered the griplets and it played again!
It plays now Non-OS on the attic-set, sounds very good (rock solid CDM1) and before i got allways listening fatigue with non-os, with the mother of all dacs TDA1540 it sounds very convincing for a only 14 bit machine! The 1540 is very fast you can hear that. Opamp is my favorite THS4032, and done some further mods as schottky's, better caps better decoupling (2 opamps had only 2 small caps with very long power lines)
So I didn't feel like ordering a new drive belt and waiting for it. I openend up the player and tried something I read either here in DIY or somewhere else, cant remember. I boiled the belt in water for 20 minutes and then let it cool. Put everything back together and presto, the tray closes without any problems. Happy camper here.
It works perfectly in every respect. It stops spinning at end of play, if stop is pressed, and it used to stop if it failed to read the TOC. Now it never fails to read the TOC.
Having read the TOC after loading using the open/close button, it keeps spinning whilst displaying the number of tracks and total time. If I press stop it stops, and the display reverts to two dots.
If it's a fault, I can't think how it can happen
weird play behavior also
Just started scanning this old thread because I picked up a CD 104 cheap recently...it had a drawer that didn't close all the way that I managed to fix with a little cleaning, re-lube of the load mech and some automotive belt treatment on the belt.
It does the same thing when I load a disc...goes into "autoplay" mode every time...playback starts and all it shows on the display screen is total play time. However, If I push stop and then restart it or select a track with the skip button it will display the track and time elapsed for that track.
Other than that the player seems to work fine. Its no collectors item, hell its scratched up, has a small pinch/tear on the ribbon cable to the radial arm/laser and smelled like a dirty ashtray when I took it out of its box...I almost didn't want ti to work...amazingly it did!!!...and the sound is smooth as silk
I hope it keeps working long enough for me to have some fun modifying it
Just started scanning this old thread because I picked up a CD 104 cheap recently...it had a drawer that didn't close all the way that I managed to fix with a little cleaning, re-lube of the load mech and some automotive belt treatment on the belt.
It does the same thing when I load a disc...goes into "autoplay" mode every time...playback starts and all it shows on the display screen is total play time. However, If I push stop and then restart it or select a track with the skip button it will display the track and time elapsed for that track.
Other than that the player seems to work fine. Its no collectors item, hell its scratched up, has a small pinch/tear on the ribbon cable to the radial arm/laser and smelled like a dirty ashtray when I took it out of its box...I almost didn't want ti to work...amazingly it did!!!...and the sound is smooth as silk
I hope it keeps working long enough for me to have some fun modifying it
Havn't been in here for a while as I have been more active over at vinylengine . Re-gripleting should be your first port of call, it fixes no end of apparently unrelated problems. Mine would only read the TOC when warmed up for about 30 minutes. Replacing (important - not just a resolder) the rivets with wire links, soldered on both sides fixed this and it plays from cold.
. Re-gripleting should be your first port of call, it fixes no end of apparently unrelated problems. Mine would only read the TOC when warmed up for about 30 minutes. Replacing (important - not just a resolder) the rivets with wire links, soldered on both sides fixed this and it plays from cold.Hello,
I got a CD 104 which doesn't work.
Usually I get lucky just fixing the griplets, but not this time.
The players makes two attempts at reading the CD, and then it stops and displays 0000.
New caps, all voltages fine. The laser focus works, but its arm will always remain close to the turntable, and releases itself only when power is turned off. I checked many many values and they are all correct. The scope showed nothing conclusive either.
Any ideas please?
Thanks.
I got a CD 104 which doesn't work.
Usually I get lucky just fixing the griplets, but not this time.
The players makes two attempts at reading the CD, and then it stops and displays 0000.
New caps, all voltages fine. The laser focus works, but its arm will always remain close to the turntable, and releases itself only when power is turned off. I checked many many values and they are all correct. The scope showed nothing conclusive either.
Any ideas please?
Thanks.
AFAIK only two wires go to the radial motor, from the servo board. One of these (-) is grounded on the servo board via a 1R5 current-sensing resisistor, and the other (+) is driven positive or negative by a complementary pair of transistors.
So, check the voltages on those two wires. One or both must be wrong.
Without knowing quite how the servo circuit works, I see two possible causes of error. First, if the radial motor coil is shorted to ground near or at its (-) end, then the motor would still work but the servo will have lost its current sensing. Easy to check by disconnecting the radial motor and measuring its resistance, and the resistance between each end of the coil and ground. Do you know what the coil resistance should be?
Second, assuming the radial motor is OK, there must be a fault in the servo circuit. In that case you need to check back through the circuit to see where the offending voltage is coming from. My manual isn't very clear, but there seems to be very little guidance on what the voltages should be around there. The voltages to the bases of the two transistors should be + and - 11.5V and their emitters should be at the levels of the +1 and -1 supplies. There are a few test points around the uA741 and HEF4053, and a few more dotted around the places the HEF gets its input from.
I could be completely barking up the wrong tree...I don't even know how these mechs find their way to the "home" position. Unlike linear carriages, they don't have a limit switch.
So, check the voltages on those two wires. One or both must be wrong.
Without knowing quite how the servo circuit works, I see two possible causes of error. First, if the radial motor coil is shorted to ground near or at its (-) end, then the motor would still work but the servo will have lost its current sensing. Easy to check by disconnecting the radial motor and measuring its resistance, and the resistance between each end of the coil and ground. Do you know what the coil resistance should be?
Second, assuming the radial motor is OK, there must be a fault in the servo circuit. In that case you need to check back through the circuit to see where the offending voltage is coming from. My manual isn't very clear, but there seems to be very little guidance on what the voltages should be around there. The voltages to the bases of the two transistors should be + and - 11.5V and their emitters should be at the levels of the +1 and -1 supplies. There are a few test points around the uA741 and HEF4053, and a few more dotted around the places the HEF gets its input from.
I could be completely barking up the wrong tree...I don't even know how these mechs find their way to the "home" position. Unlike linear carriages, they don't have a limit switch.
Thanks.
Trouble is, the manual doesn't say anything about how the coil (tested good) is fed by the servo. So there is voltage alright, it changes a bit when I press play, but the radial motor keeps the carriage stuck to the turntable.
Does anyone know how voltage changes during the complete travel of the swing arm?
Trouble is, the manual doesn't say anything about how the coil (tested good) is fed by the servo. So there is voltage alright, it changes a bit when I press play, but the radial motor keeps the carriage stuck to the turntable.
Does anyone know how voltage changes during the complete travel of the swing arm?