54cm Goldstar tv Model no: CZ 20A 90Y

Before replacing the switching output IC STR, you have to check all its associated components on board, especially low value resistors, and zener diodes. If you wish to get some details; check the site linked here. Surf the site with patience. Pull up older posts.
http://electronicshelponline.blogspot.com/
repair procedure of STR based power supplies, and circuit diagrams are given. Just type in the STR number in the search box at the right side to get gathered related posts.

Zener Diode Code
Visit this site.

If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/
Power supply circuit diagram using STRF6656 is given. There are many TVs using this circuit in the SMPS. You can get details there. Type in the STR number; in the search box at the top right of the display window; to get gathered related posts.

just read the model and then google it, beside, if you short them, you need to replace them with same value, and this will be determined by the circuit, if you did not change the circuit - just buy two new diodes and install them, do not bother with voltages as they have some tolerance and type will determine it.

Check all the associated components, resistors, zener diodes etc: before replacing it with a new STR. If you wish to get the schematic and some other details, check the site linked here. http://electronicshelponline.blogspot.com/
Pull up previous posts by its left sidebar, or type in the brand name and model number to of your set, to its search box, and press 'Enter' or view it in Mosaic / Timeslide option.

Replaced the ZD3 on the Boston Acoustics Soundware xs 5.1 subwoofer with a 18 Volt-1 Watt Zener part number 1n4746a. and works like brand new.

The secondary output voltage comes out from is more than it should be there. That is why, the protection zener diode blows off, as soon as you switch ON the set. First find and repair the power supply regulator, for correct output voltage. Refer its repair book for details. After repair include the zener diode in place. OK.

If you have a digital tester or analog try to check the voltage reading from the power supply if high or low or no supply.Check first following voltage location and section. * Check the AC voltage from ac cord to fuse and before the bridge type diode. * Check the DC voltage after the bridge type diode.if normal voltage. * Then check the voltage into the filter capacitor to regulator ic.the power ic.If theres a input voltage in the power ic,check the output voltage going to harizontal output.If no output the problem is you power output.You need to replace it.

Part number is str-t2268. I had to replace a zener diode zd911 also. Part number 1n5226p.

Excellent visual acuity technique!! I try to teach that procedure.

IC F6629B is probably shorted and at least one other part will

be open, possibly a zener diode,a fuse,a resistor or combo.

The service diagram would help.Be sure to use OEM first quality

parts.Let me know if you need more help.