stylus heat issue - power supply - VMS 70
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stylus heat issue - power supply - VMS 70
Hi,
Perhaps one of you has experience with a stylus heat issue on a VMS 70 / SX 74
The meter shows no current and the cut shows no heat. I tried more than one stylus, and checked continuity on each. I took out the the TE 66 panel and checked the connections to pot, meter, socket. I tried bypassing the meter, and then tried putting a multimeter inline in place. In all cases I measure 0 current when the head is in the down position but I see a little blip in the current meter as the head engages and again as it disengages. I also see a dip in the electrical depth meter as the head engages/disengages. Voltage across pins 23 and 30 on the NG 66 H card is 4.5 volts with the depth engaged(START), but drops to less than 1V when the head drops. My electronics knowledge is limited, but I'm guessing this is a power supply issue, possibly a voltage or current limiter.
Any ideas? thanks,
-Kevin
Perhaps one of you has experience with a stylus heat issue on a VMS 70 / SX 74
The meter shows no current and the cut shows no heat. I tried more than one stylus, and checked continuity on each. I took out the the TE 66 panel and checked the connections to pot, meter, socket. I tried bypassing the meter, and then tried putting a multimeter inline in place. In all cases I measure 0 current when the head is in the down position but I see a little blip in the current meter as the head engages and again as it disengages. I also see a dip in the electrical depth meter as the head engages/disengages. Voltage across pins 23 and 30 on the NG 66 H card is 4.5 volts with the depth engaged(START), but drops to less than 1V when the head drops. My electronics knowledge is limited, but I'm guessing this is a power supply issue, possibly a voltage or current limiter.
Any ideas? thanks,
-Kevin
- smithadamm
- Posts: 63
- Joined: Tue Jun 03, 2014 1:32 pm
- Location: Austin TX
Re: stylus heat issue - power supply - VMS 70
You are right, it could certainly be a bad regulator. I would take a hard look at the large filter caps in whatever power supply provides power to the heater. I would also check any tantalum caps that might be in the psu.
Re: stylus heat issue - power supply - VMS 70
Have you checked the fuse on the NG66H1 card (far left)
JJG
JJG
Re: stylus heat issue - power supply - VMS 70
Thanks for the tips,
There were a few things wrong with the fuse housings that were causing intermittency, not on the card itself, but on the panel to the right. It all works again.
-kp
There were a few things wrong with the fuse housings that were causing intermittency, not on the card itself, but on the panel to the right. It all works again.
-kp