Re: SC502 Old Enough to Smoke?


Hi Dave,
Tantalum caps are the most obvious culprit. They usually have a small value (10 ohms for example) resistors in series with them. When the tantalum shorts the resistor overheats and disintegrated into a little black cylinder. Sometimes the area around the resistor is black too. Most of the time these tantalums are near the connectors on the rear where power comes into the plugin. The burned up resistors are a good thing to look for and usually easy to spot.

Next thing to do is check each tantalum capacitor for a short by putting an ohmmeter across it

Dennis Tillman W7pF

-----Original Message-----
From: [] On Behalf Of Dave Daniel
Sent: Tuesday, June 02, 2020 12:50 PM
Subject: Re: [TekScopes] SC502 Old Enough to Smoke?

Is the ‘scope working to spec?

On Jun 2, 2020, at 15:40, DaveH52 <@DaveH52> wrote:

I have a TM506 that came with a full load of plugins, all of which seem to work OK except the SC502 which emits a magic smoke smell. My uncalibrated nose tells me it's coming from the A1 main board on the bottom. My uncalibrated eyes did not detect anything looking discolored or burnt just an old spider nest that has since been removed. My uncalibrated nose says it's not coming from the HV supply section. Are there any "usual suspects" I should investigate first, before applying power again?

Dennis Tillman W7pF
TekScopes Moderator

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