Phonoland

The 560 ohm are not an error, they are the original configuration of the first SHP series.

Here are some schematics in PDF form which incorporate -some- of the necessary changes (scroll down to the SHP doc's):
http://arcarc.xmission.com/PDF_Jukebox/ ... chematics/

As Ron suggests, getting a manual which outlines the mod's necessary to make these amp's safe and reliable is a good idea...and something I didn't have in the late '80s when I was dealing with these flawed designs.

Rob

I am finding out there are many different little issues, changes, tweaks, whatever you want to call them for these Microlog systems. I have finished restoring my Seeburg hf100r without much trouble and minor changes from original production, same as with my Trashcan (146). Being in the IT field myself, technology is a benefit but also a pain I do fully understand that Jukeboxes, like my pinball machines, were never truly meant for the consumer market and would be maintained and supported by techs that knew these units inside and out along with any new service memo for changes e.g. the 4 jumper wires on the driver board for the SHP amp.

I understand now that R75, R76, R98 & R99 should all be replaced with 100 1w resistors, I will take care of that and I will also get a copy of Tony's SHP book.

In the mean time I am assuming that one of the transistors is causing this fault, I will divert my attention there for no until I get the book.

I do have to say something about all these changes described in Tony's book. I can not imaging that every single unit globally has had all, if any of these changes and are still in properly working condition. There is a very large difference between changes to make something safer and more reliable. I have restored Pinball machines for 20 years and it was very rare that a coil, cap or resistor was substituted to make something safer or more reliable and I am having a difficult time understanding why the first thing people say is "You have to do what Tony said".

Next I know I will hear that I asked for help and people are sharing their knowledge as to how to resolve an issue, yes and I do appreciate peoples time and knowledge, we all do, but I just find it odd that Tony's book is the end all be all.

Why would you need to replace 4 560 1/2w resistors with 100 1w replacement? A resistor change is overkill, its not a capacitor.
Moving C46 seems to me a bit odd as there is no change from an electrical aspect.
The jumper wires I can understand to a point but makes future maintenance on the amp a pain as now the driver board is hard wired into the unit.

Like I said, I greatly appreciate everyones help and opinions but I have a good working knowledge of electrical infrastructures from computers to pinball machines... Please no jumping on me either for questioning the suggestions as I am not trashing anyone, just questioning changes that a lot of others may have the same hesitance about. I know of at least 5 SHP-1 amps now that are original, that have not had any of these changes and have been working for years and continue to work, even in a commercial environment.