EBME Forums Forums Maintenance Service Manuals & Schematics Need Pinout/Enable Signal for TECTROL TC89M-1429

Hello everyone,
I am attempting to troubleshoot/bench test a Power Supply Unit (PSU) with the model number TECTROL TC89M-1429 (Philips P/N: 4535-613-82672), which is used in the Philips HD11/HD11XE Ultrasound system.
The unit is not fully enabling. I understand that this PSU requires a specific "Enable Signal" (likely AWAKE_N or N_POWER_ON) via the ribbon cable connector to switch from standby mode to full power output.
My Questions are:

Which Pin on the Ribbon Cable Connector corresponds to the Enable/Power-On Signal?

What is the expected voltage logic for this pin (e.g., Active Low 5V to 0V, or Active High 0V to 5V)?

Are there any known Test Points or common internal component failures (like specific capacitors) that prevent this unit from fully starting, even if the enable signal is present?

Any documentation, schematic snippets, or confirmed pinout details would be highly appreciated. Thank you for your support.

Welcome to the forum Mohamed.

Am I right in thinking that this is an old machine?

Have you taken a close look at the power supply?

Anything suspicious there ... blown capacitors, for instance?

Any other clues or information ... fan not working. etc?

Meanwhile, here is an interesting YouTube video. I think the guy answers your question ... but it's in Spanish (maybe Portuguese). Try the Google translator.

It gives something like:-

U440 . OPTO MOC 8102 , JOIN PIN 4 AND 5 (COLLECTOR AND TRANSMITTER) ... presumably:- emitter.

Good luck!