Half Life
New Member
First, a brief introduction. Long time lurker, just joined. I've found lots of good info on this site. I am a former U.S. Navy Electronics Technician. As a hobby I restore/refurbish pinball machines, both electro-mechanical and solid state. I have 7 pinball machines in my collection now.
Second, a big thank you to Avionic, brutal and amr2 for their many posts on the M-80. Good stuff there.
Now on the the rest of the story (nod to Paul Harvey). Got a free M-80 from a friend of my brothers that said he wasn't sure if it worked anymore. Took the cover and bottom plate off to do a visual inspection and didn't find anything out of the ordinary other than the distinct smell of cigarettes. Unit must have been in a bar during its life.
Plugged it in and turned it on. Unit went straight to protection mode. Turned the unit off. I checked the various connectors to ensure they were snug. Turned the unit back on and this time no protection mode. I used my cell phone (playing Pandora) to provide an input although I knew it wasn't going to drive the amp properly. Got very weak sound but sound nonetheless. Adjusted the R/L Level controls, got some scratching and then back to protection mode. Searched the internet and found this place. Learned about the bond glue issue and took stock of the affected components. Also checked all of the transistors on both heat sinks and found them to be ok.
Placed order for the passive components I needed from mouser and while waiting decided to see if I could find a C-80 companion. Was lucky enough to locate a working one. Got it home and opened it up looking for the bonding glue. Yep, inside this unit too but not near as much. Only had to replace two resistors and do some cleaning. Checked the C-80 with my cell phone and some headphones and it works like a champ.
Parts arrived and replaced in the M-80. Connected the unit to its mate and fired it up (hooked to A & B sets of speakers). No protection mode - woo hoo! Noted the display center not lit but I can hear music. Right channel sounds weak, adjusted levels and still get scratching (need to get more deoxit). Then I hear a "pfffttt" and the unit goes straight into protection mode. Turned the unit off and will look at it later this morning.
Sorry for the long post. Just wanted to introduce myself and say thanks to those that help on here. Without your help I wouldn't have gotten as far as I did with my new-to-me gear. Can't wait to get them working correctly.
Second, a big thank you to Avionic, brutal and amr2 for their many posts on the M-80. Good stuff there.
Now on the the rest of the story (nod to Paul Harvey). Got a free M-80 from a friend of my brothers that said he wasn't sure if it worked anymore. Took the cover and bottom plate off to do a visual inspection and didn't find anything out of the ordinary other than the distinct smell of cigarettes. Unit must have been in a bar during its life.
Plugged it in and turned it on. Unit went straight to protection mode. Turned the unit off. I checked the various connectors to ensure they were snug. Turned the unit back on and this time no protection mode. I used my cell phone (playing Pandora) to provide an input although I knew it wasn't going to drive the amp properly. Got very weak sound but sound nonetheless. Adjusted the R/L Level controls, got some scratching and then back to protection mode. Searched the internet and found this place. Learned about the bond glue issue and took stock of the affected components. Also checked all of the transistors on both heat sinks and found them to be ok.
Placed order for the passive components I needed from mouser and while waiting decided to see if I could find a C-80 companion. Was lucky enough to locate a working one. Got it home and opened it up looking for the bonding glue. Yep, inside this unit too but not near as much. Only had to replace two resistors and do some cleaning. Checked the C-80 with my cell phone and some headphones and it works like a champ.
Parts arrived and replaced in the M-80. Connected the unit to its mate and fired it up (hooked to A & B sets of speakers). No protection mode - woo hoo! Noted the display center not lit but I can hear music. Right channel sounds weak, adjusted levels and still get scratching (need to get more deoxit). Then I hear a "pfffttt" and the unit goes straight into protection mode. Turned the unit off and will look at it later this morning.
Sorry for the long post. Just wanted to introduce myself and say thanks to those that help on here. Without your help I wouldn't have gotten as far as I did with my new-to-me gear. Can't wait to get them working correctly.
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