Penta mk III does not power off

[Falkor]

Hi guys, have an annoying issue with one of my penta’s.

It will not power down. led stays green.

either using the switch or when in use through powerlink.

I did observe the led to “try” to switch to red.

poweramp has been recapped and dry solder joints corrected.

Switches work.

I’m an experienced technician so will be able to trace the problem but as taking apart a penta is no fun who know mayby someone has ran into to problem before and save me some time.

any known issue’s with transistors or diodes in this circuit perhaps.

 

[Homersaurus]

I’ve had this with Penta II, 6622, but it’s the same issue for 2s and 3s.

See the archive forum at:

https://archivedforum2.beoworld.org/forums/p/17590/153806.aspx#153806

https://archivedforum2.beoworld.org/forums/p/45751/330229.aspx#330229

As I wrote in the archived post:

“The transistors TR3 and TR4 are on PCB 2, the Control board which, as you say, is the front panel. So 2TR3 and 2TR4 refer to (PCB) 2 TR 3 and (PCB) 2 TR 4. The transistors you have identified on the board are the ones to change. TR3 failing is a common fault and can also be the cause of a Penta always being green and not going into standby (red).”

 

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