Rowe-Ami R-81 DC to DC Converter question

[bjwizzer]

Hello,

I am trying to get a R-81 working, there is a board called a  DC to DC Converter (pn 301-07541) that is connected
directly to the "memory unit" and there is a battery pack plugged into the Converter board.

My first guess would be that it is some type of battery backup allowing the R-81 to keep its' settings should
the power go out.

Question 1 - can the R-81 operate normally without this board?

Question 2 - the batteries were dead and leaked into the battery insulator causing the insulator to fall apart,
                   will to board function without the batteries?

Question 3 - there is a 56 ohm resistor (R913) literally burned off of the board, any idea what component may have
                   done this? (resistors already ordered)
 
I also have to issue as I read in some other post of the R-81 picking ghost selections when first powered on.
Hitting the Memory Clear button only works sometimes to clear the problems.

This jukebox is in pretty decent shape and I like to get it operational, but if it's going to be a real PIA,
then I would consider parting it out.

Thanks,

BJ

[Ron Rich]

Hi BJ,
My GUESS would be that it is a battery back up for memory--- I am not familiar with Rowe's of that vintage--hopefully the service manual can be of help on the resistor (BTW--if burned up, how do you know the value ?) See the sticky above about common problems--- Hopefully "amiman" (Alan) will see this and chime in--- Ron Rich

[bjwizzer]

Ron,

I got a service / parts manual with the Rowe-Ami R-81 jukebox.
That is how I got the value of the resistor.

Anyway, the jukebox while it still has others\issues, nothing seems to be affected by the removal the the 
Converter board.

Meanwhile I check the Sticky you recommended.

Thanks again for your help,

BJ 

[amiman66]

Hi BJ,

You are correct the converter board is not required for normal operation. Its purpose was to hold selection information if the jukebox was turned off for any reason.

If you need to work on these boards, The Memory Unit and the Selector Logic have CMOS chips on them and effected by static discharge, you need to use safe handling techniques.

When people send use their boards for testing/Repair we always ask for the Memory Unit, Selector Logic and Mechanism Control to test them as a set of boards. The Memory Unit and the Selector Logic boards work in tangent and any adjustment to either variable capacitor effects the other board with regards to the clock & data pulses.

Regards
Alan

Alan Hood
ami-man
UK