Help! I have been working on this 246 for over a year! Indicator lights not working

Mstone

New member
Somebody please help me! I have this machine functionally working but every time I think I am done and put it back together, something breaks! I have been working on it over a year! (With a long multu month break in the middle however) But I started back up again a couple weeks ago and its the same old thing it seems to like to do. Fix it, put it back together, new issues. Anyway...
The indicator lights for the two memory lights and the zero return lights are not working. The record indicator light wasnt working but I finally figured out it was a ruined solder joint underneath the light. I even tried tracing voltages all over, looking at the service manual and such. I even ordered a new Mitsubishi M54517p darlingotn transistor array to replace the chip U507 on Control board A because I saw the voltages not getting through the chip on the channels where the lights were not working, and the voltage was getting through on the ones for the play and pause indicator lights which worked. So I am stumped.
But now a new issue unfolded after I fixed the record light of course! The same segment on each number of the display stopped working and I do not know how to fix that either. It is the bottom right segment.
Thank you!
 
You say you need help but all the kinds of things you describe is what we called a bull in a china shop scene. Ask yourself why the technicians that worked on these all the time never had any of these kinds of problems. Regardless rough handling of connection and connector just barely soldered in is a problem I see in Porta Studio and reel decks alike. The more someone moves cables around in some of these newer reel decks like the X2000R the more stuff seems to stop working. It is the horrible wave solder and tiny little foil patterns they used there. The 246 is really built better than that but there is always the possibility of broken joints where rough handling happens.
Control chips have rarely failed in these units- when I hear of people changing them I already have an idea of how it is being worked on.
Each problem must be worked on separately and then no jumping around to other in the midstream as that just causes confusion.
It should not take a year to fix this unless you have 200 units here to work on as well. Some of the hardest problems to overcome is motor selection where original ones are not to be found.
 
To date I have never had a zero return LED to go out not that it is impossible to happen as some LED's in deck do burn out randomly now and then. I replaced the LED and then the LED works. It is not always a driver chip. More than likely it will be a bad LED and that can be checked with a DVM or a power supply with a resistor or as is many times the case bad solder joints. So what did you find when the IC was changed? Same problem?
 
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