SteveJ
Member
My Robotron is missing some sounds, and others are incorrect. Based on advice from here, What I've done so far:
1. Adjusted switcher voltage (it drifted to 6V -- this could have caused it)
2. Checked Cable continuity between ROM and Sound boards
3. Replaced IDC connectors with Molex
4. Installed Bob Robert's cap kit on Sound Board
I researched the ROM/SOUND interface, and tested the pin headers on the sound board. Basically, by grounding each of the pins, a certain sound is generated (this is what the "sound lines" self-diagnostic does). If each pin works, then theoretically, the combination of pins will work as well.
So I grounded each pin in turn, and when I got to pin 7 (sound line 5), The sound would not turn off, even when the pin was "ungrounded". The other sounds shut off as soon as I removed ground.
First question: Is this normal, or is my pin #7 sticking "low"? If so, could this be the 6802 or 6821 on the Sound Card?
Second Question: I'm not sure what "normal" sounds should be for these tests... has anyone posted (youtube or wav file somewhere) what a functioning robotron diagnostic sounds like? The troubleshooting material only says "makes a sound", but obviously that isn't good enough in this case.
for example, what sounds should come out when the sound board self-diagnostic switch is pressed? What sounds should the "sound line" diagnostics make?
Any help is appreciated, I'll try to trace through the boards and see where pin 7 leads me.
If I get this fixed, I'll record and post the working sounds myself
1. Adjusted switcher voltage (it drifted to 6V -- this could have caused it)
2. Checked Cable continuity between ROM and Sound boards
3. Replaced IDC connectors with Molex
4. Installed Bob Robert's cap kit on Sound Board
I researched the ROM/SOUND interface, and tested the pin headers on the sound board. Basically, by grounding each of the pins, a certain sound is generated (this is what the "sound lines" self-diagnostic does). If each pin works, then theoretically, the combination of pins will work as well.
So I grounded each pin in turn, and when I got to pin 7 (sound line 5), The sound would not turn off, even when the pin was "ungrounded". The other sounds shut off as soon as I removed ground.
First question: Is this normal, or is my pin #7 sticking "low"? If so, could this be the 6802 or 6821 on the Sound Card?
Second Question: I'm not sure what "normal" sounds should be for these tests... has anyone posted (youtube or wav file somewhere) what a functioning robotron diagnostic sounds like? The troubleshooting material only says "makes a sound", but obviously that isn't good enough in this case.
for example, what sounds should come out when the sound board self-diagnostic switch is pressed? What sounds should the "sound line" diagnostics make?
Any help is appreciated, I'll try to trace through the boards and see where pin 7 leads me.
If I get this fixed, I'll record and post the working sounds myself
