TTI / Thurbly Thandar TSX3510 Repair

[TheBay]

I have had this power supply for some time and has served me really well. It is a Mixed mode design based on SMPS but precision.
It's just the Standard non programmable TSX3510 35v 10amp, the version that has a dark grey case, not the recent white one.

Recently I was trying to charge some SLA batteries and forgot I had one trickle charging, ever since then this PSU has been playing up.

The fault is, if anything draws over 800ma+ the Constant Voltage light flickers on and off (Does not go to constant current, which is correct), and the LED segment display shows a brief drop in Voltage, If I have a multimeter attached it constantly shows the voltage the the display drops to, not what is displayed on the PSU

Constant Voltage/Constant current switch over is working correctly.

If I connect a dummy load at say 500ma it all works correctly and the multimeter reads correctly.

Also when it is not working correctly it makes an awful buzzing/whine from one of the SMPS transformers, this PSU was near silent previously.

I think an SLA has backfed or shorted out causing damage. I do have the schematics for this PSU, any help will be gratefully appreciated.
I love this PSU and would love to get it back in action.

[macboy]

Do you have the full service manual or just schematics? I can share the service manual with you if needed.

[TheBay]

I've been sent a service manual from TTi.
I guess that's the same as what you have?

[djsb]

Did you ever get this fixed? Just curious. Thanks.

[TheBay]

Did you ever get this fixed? Just curious. Thanks.

It was the large capacitors in the primary side.