Re: Tek 465B Magic Soot


The 465B is a fine analog scope.

Ok, first, the black soot is just that. It is attracted by the high voltage field around the red cable. It is just mostly carbon exhaust.

The fuse is in the unregulated +15 supply and _IF_ you are very lucky, it is just a shorted tantalum capacitor C4006. The capacitor is under the HV shield in the corner of the board and is a 47uF-35 volt dipped tant. You can just use a good quality 105°C aluminum electrolytic

The second most likely thing that blows that fuse is the HV multiplier module. They run around $50+ and it is a task to replace. The procedure is covered in the service manual.

Do you have the service manual?


----- Original Message -----
From: [TekScopes]
Sent: Thursday, November 09, 2017 6:43 PM
Subject: [TekScopes] Tek 465B Magic Soot

I bought a 465B as-is, etc. and thought I could get it up and running and discovered fuse 4508 was blown. I put a 1A in it's place and that blew also.

I decided to move this beast off my bench and while doing so discovered some magic soot on the inside of the case and on a CRT connection ? (red wire). also. Is this thing worth fixing? I have another scope that works, so theres no urgency to it.

Join to automatically receive all group messages.