Seeburg LS3 won't reset after warming up

Hi folks-

Thank you in advance for any advice you can offer me. I have had this Seeburg LS3 in my family for 25 years but it hasn't really worked in awhile. I've been testing and tweaking and have come very close to having it working again but I have a problem that I don't know how to fix. After the first song or two plays, the red re-set/re-select lights up and won't go off. I can't select another song after that. Any ideas on where to start looking are very appreciated. I'm not much of an electronics guy but I own a soldering iron and know the difference between a capacitor and a resistor.

Thank you,
Kevin

Hi Kevin,
Check the - 13 and -27 voltages, when cold, and when warm--if they don't "track together", that's your problem--this is especially true if you have a DTP-1 with a "Code date" on it. Ron Rich

Hi Ron-

Thanks for your help. I'm not entirely sure what you mean but it is probably because I'm pretty novice. I have a few control centers shells and a few different PCB's and I've tried several combinations of parts but I think it must be with the 311125-D pcb (I only have one of them)

The voltages seem to stay the same before and after the reset problem begins. The +27 is consistently low - about +25.7.

readings are:
-27.2
-13.4
+25.7

Any additional thoughts? Thanks in advance!

Sincerely,
Kevin

Hi Kevin,
Those voltages are within range--Are you saying that this problem goes away if you use another DCC ?
Ron Rich

Another interesting observation - I can program in 10 songs before it heats up and stops allowing me to enter songs. It will play them all but I can't reset again until I shut it off and let it sit for awhile. Then when it comes on, I have to press the reset button 3 times to get it to take. I'm not sure if this is just a coincidence but I see a pattern.

Hi Ron,

No, the problem doesn't go away with the other DCCs. I only have one working combination thus far. Perhaps the problem is not the DCC.

Sounds as if it's the DTP-1--what is the "warranty date" on it ?
Ron Rich

September 1, 1981

Hi Kevin,
Unusual that one with a date that late would do that, but it is my guess that the DTP-1 is at fault. Earlier dated units had a problem in that area, but it was resolved years before that one was made. If you have the skills needed to work on LSI units, you really should purchase the late Tony Miller''s "Black and gray box book"--3rd edition ! CAUTION, "just opening" that unit can destroy it ! If do not have the skills needed, you may either purchase another DTP, or send it to me for repair--PM me, if you wish to do so. Ron Rich

Thank you so much Ron. I truly appreciate your expertise. I'm not going to tackle the repair myself. I'll PM you.