Re: PG502 power lamp off


It is pretty clear from an internet search that this is an obsolete part.
As a result, if you hope to find a suitable replacement you have to do a
little work yourself. What is the description of the part in the parts list.
That can tell you a lot. You should also be able to look at the circuit
schematic and determine what purpose it serves.

By doing a little investigation you may discover that a commonly available
substitute will serve your needs very well. Chances are it is a simple,
common switching transistor. GE was the original manufacturer and most of
what they made were ordinary (nothing special) transistors.

Dennis Tillman W7PF

-----Original Message-----
Sent: Sunday, February 14, 2016 2:12 PM
Subject: RE: [TekScopes] PG502 power lamp off

Hi Christoph,
Wouldn't it be more likely that the bulb burned out than a transistor went
The TM500 plugins all used ordinary incandescent bulbs and they all, in my
opinion, had relatively short lifetimes compared to how long the plugins
have been in use. Of course when most of the plugins were designed LEDs were
not common or as cheap as these bulbs were. The power bulbs in most TM500
plugins I own are dead by now.
For a while I was buying exact replacements for the bulbs when I could find
them but now I just replace them with LEDs whenever a dead one becomes
annoying enough.


-----Original Message-----
Sent: Sunday, February 14, 2016 1:43 PM
Subject: [TekScopes] PG502 power lamp off

With the TM5006 frame I recently acquired came a couple of modules.
After I luckily got the PG506 repaired fairly easily I also have one
PG502 needing care.

The power lamp is off when seated in a powered up TM frame.

I suspect Q650 (X44C282). Anyone knowing a replacement type for this ?
Posted by: christophkukulies@...

Posted by: "Dennis Tillman" <@Dennis_Tillman_W7pF>

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