08-10-2016, 04:07 PM
I'm trying to troubleshoot this tester due to erratic readings. I found the (Q7) voltage reading not right.
This transistor has a heat sink that pushes down on top of it. So it runs at least fairly warm. It is in a TO-18 package.
It is staying cold to touch, any how the voltages called for on schematic are on the left. Mine on right.
Emitter _-6.7v Emitter -6.7v
Base -7.4v My readings are: Base -7.4 v
Collector -21.5v Collector -12v
above readings were taken to ground with fluke DVM
The collector voltage seems way low.
The transistor has the # 3-009 on it. I'm trying to figure out what transistor equivalent to purchase.
It shows it being a PNP on the schematic, but the Mouser site has a 2n3009 as NPN.
http://www.mouser.com/ds/2/68/lssgp056-12668.pdf
I'm confused Here is what mouser shows available.
http://www.mouser.com/Semiconductors/Dis...kaZ1z0y4cn
Can someone advise me on which transistor I could use as a replacement? Thanks
Here is the manual with schematic on page 45 and voltage chart on page 32. all transistors on the tested within +/- 5% except the collector of Q7
file:///C:/Users/Mike/Downloads/400e_service%20(2).pdf
Sorry I see the download of schematic did not work will try to get it up
This transistor has a heat sink that pushes down on top of it. So it runs at least fairly warm. It is in a TO-18 package.
It is staying cold to touch, any how the voltages called for on schematic are on the left. Mine on right.
Emitter _-6.7v Emitter -6.7v
Base -7.4v My readings are: Base -7.4 v
Collector -21.5v Collector -12v
above readings were taken to ground with fluke DVM
The collector voltage seems way low.
The transistor has the # 3-009 on it. I'm trying to figure out what transistor equivalent to purchase.
It shows it being a PNP on the schematic, but the Mouser site has a 2n3009 as NPN.
http://www.mouser.com/ds/2/68/lssgp056-12668.pdf
I'm confused Here is what mouser shows available.
http://www.mouser.com/Semiconductors/Dis...kaZ1z0y4cn
Can someone advise me on which transistor I could use as a replacement? Thanks
Here is the manual with schematic on page 45 and voltage chart on page 32. all transistors on the tested within +/- 5% except the collector of Q7
file:///C:/Users/Mike/Downloads/400e_service%20(2).pdf
Sorry I see the download of schematic did not work will try to get it up