Nautilus repairs???

[Badd427]

DMCll with auto tune but it’s not a 2b and four 9v batteries,Plugged in 15” coil and turned on and nothing I have good batteries I checked voltage it’s around 18v was working perfectly fine a few seconds before switching coils,any help would be appreciated

[Badd427]

DMCll with auto tune but it’s not a 2b and four 9v batteries,Plugged in 15” coil and turned on and nothing I have good batteries I checked voltage it’s around 18v was working perfectly fine a few seconds before switching coils now it’s dead with the coil I had just removed,any help would be appreciated

[Carl-NC]

Was the 15" coil made for the DMC2?

[dbanner]

I think there were 2 size of coils made for these 2B detectors. Not sure about the II. The 15" was the larger option.

[Mario-j23]

The DMC II coil has a four-pin connector and does not have a preamplifier inside. Check if any of the probe plug cables are broken. Nautilus doesn't work without a probe! It must be connected for the negative voltage converter to work. If so, I've attached a diagram that may help you.

[Carl-NC]

I would start with inspecting the coil connector pins. Since neither coil works, it would more likely be the connector mounted on the control box. If the connectors look OK, then I would measure the coils to make sure they are OK. Resistance at a minimum, preferably inductance too. Make sure both coils reasonably match. If the coils seem OK, next step is to dive inside the box and measure internal voltages. The -6.5V on the charge pump would be a prime suspect.

[kt315]

I think there were 2 size of coils made for these 2B detectors. Not sure about the II. The 15" was the larger option.

Nautilus's coils used preamplifier inside. it was FIRST coils - before ML begun to set preamp directly in a coil. first of all needed to open coil and check the transistors.

[Mario-j23]

Fellow Badd427 has a problem with DmcII and this detector does NOT have a preamp inside the coil! He is still on the Pcb so it is easy to check all the components. As Carl wrote I would start with the pins. Maybe they're snowed on or not making contact. I would measure the resistance and inductance of both probes. Tx about 10ohm and 2.7mH, Rx 30ohm 8mH. With the probe plugged in, the genetator should work at about 14kHz. If the generator works the inverter should produce about -7V. If the detector still does not work maybe some electrolytic capacitor has punctured. Time does its job check the checks are not faded. Good luck with the repair.

[Qiaozhi]

The attached files might be useful.

[Badd427]

This is where I loose voltage on the board

[Altra]

Can you take a photo on the top where you are probing? Need to see the parts

[Badd427]

First probing pic is a 4 prong capacitor second probing pic is a 3 prong transistor,I’ll get a pic posted asap