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Tek 2430 (Non-A) with Strange Problem (same with Tek 2465)


 

On Thu, Aug 6, 2020 at 01:58 AM, Harvey White wrote:
Depending on the smell (5$, 10$, 20$.....) it could be the RIFA capacitors on the power input.
Just happened to me... I made some experiments with a 2465 that seemed to work properly. After 10 minutes or so, white smoke came out of the scope! It smelled like burned wood. A quite different taste than when these famous line filters from Schaffner go up in smoke.

Opening up I could spot the RIFAs, one of them cracked and the series 68 ohms resistor burned, too. No mess around the cap like with the Schaffner.

The mechanics of the scope are a bit awkward. I had to unmount the whole supply to be able to get to the board. In the process I had to take of the fan from that very special Tektronix-Motor, probably braking the plastic clamps of the hub on the motor's axis. Will have to improvise to get it fixed again...

To Mike: if you really cannot spot a defective component you might try and find someone with an IR-camera. Thats a very effective and efficient tool for spotting components that tend to overheat. The electrolytics in my power supply all look fine.

cheers
Martin

PS: thats how it looks, (in my case it was the other one of the pair) https://groups.io/g/TekScopes/photo/248127/5?p=Created,,,100,2,0,0