8562EC Power Supply Repair

[CrazyTiger]

Hi,

I am trying to repair a 8562EC Spectrum which is not turning on. The power supply is doing a on and off cycle. I have looked into all most of the major startup area and secondary area, so far I am yet to find anything shorted or open.

To be sure I have also removed and checked all the FET out of circuit, capacitors tested and mosfet driver IC's been replaced as well. Everything looks good so far, except few capacitors which I have replaced.

Looking at the small board, I have my doubt on a component marked LT2105, I am able to find this being sold in aliexpress, but I am not able to find a datasheet for this chip. I can find a LT210 but not 2105 Any idea what this chip could be?

[eblc1388]

It is a 5V ultra low drift 5ppm/^oc voltage reference LT1021.
https://www.analog.com/media/en/technical-documentation/data-sheets/1021fc.pdf
 
Also, have you downloaded the maintenance manual for 8562EC at the following site, which has a very detailed troubleshooting procedures regarding the 1.5 second "on/off kicking" startup of the power supply on Page 624?
https://www.testunlimited.com/pdf/an/08562-90219.pdf