IPOs 150 Polaroid TDA-03211C bad diode D10 question

[nfadel]

I would appreciate any assistance from anyone who has experience with this set and this problem.

It has a shorted diode D10, a common problem, design flaw causes D10 death when the VGA input is used. As per this post it was said that the board and TV can be powered up if D10 is removed. Apparently, D10 connects the transformer secondary to 20V on the header that goes to the tuner / input board.

If I replace the diode it should work again according to others experiences. However, D10 will short out again if I use it as a VGA monitor. This set is relatively useless to me if I cannot use it as a monitor.

I have 2 questions. Is it safe to run the set continuously as a monitor with the diode removed?

And, what is supplied by the 20 volts? What will be lost? The audio (my guess)? The DVD player?

I found the schematic for this power supply, but not being an electronics tech, I can't make much sense of it.

[ReeceyBurger123]

Re: IPOs 150 Polaroid TDA-03211C bad diode D10 question

Instead why dont you use a Hdmi to vga converter they work ? Also the Tv wont run likely with that diode removed as it will detect a missing voltage and probably wont start.

[budm]

Re: IPOs 150 Polaroid TDA-03211C bad diode D10 question

The diode failed because of the bad heat management, look at how they attach the heatsink plate to the diode. They should have use TO-220 case style diode (low Vf) with proper heatsink. Not the VGA usage problem.

[nfadel]

Re: IPOs 150 Polaroid TDA-03211C bad diode D10 question

I found this which led to this as a recommended direct replacement, 4A instead of 3A, which led me to this as a possible TO-220 replacement, but I don't know whether the specs are adequate or not. Could I use a TO-220 or other package with a good sized heat sink and relocate it off the board?

Some of the specs are different, Voltage - Forward (Vf) (Max) @ If, Current - Reverse Leakage @ Vr, and Reverse Recovery Time (trr) are all different. I don't know if these values would be acceptable. i'm pretty much a complete amateur at circuit theory and design. Perhaps a better off the shelf heatsink design exists for the existing DO-201AD package diode you might know of?

I had narrowed it down to this and then selected TO-220.

[nfadel]

Re: IPOs 150 Polaroid TDA-03211C bad diode D10 question

I wonder if using the existing DO-201AD package HER303 / HER304 replacement diode by soldering a copper heatsink to each end as shown and relocating it off the power supply board somewhere next to a cooling inlet vent would provide enough extra heat dissipation?

[ReeceyBurger123]

Re: IPOs 150 Polaroid TDA-03211C bad diode D10 question

Or just get some little Vga heatsinks and use thermal glue and secure them to the diode.