Re: Dynex DX-LCD37 Bad Caps!

It was the power button!

Something had gone wrong mechanically with the tact-switch for the power button and it was just constantly flapping on and off. I disconnected it (for now) and the TV is back to normal!

Turns out those 2200uF caps probably weren't bad... I was in a hurry when I tested them because I had to leave and I don't think I calibrated my LCR meter before I took the reading, so the "high" ESR I measured was probably just a normal ESR + the test leads. That's probably the same reason I didn't see...

Re: Dynex DX-LCD37 Bad Caps!

Right, replacing the caps...I still don't have them yet but wanted to post my homework as far as ordering them in the hope that it saves someone else the trouble.

I used the Nichicon HD series where I could, the only two exceptions are for the (2) 2200uF 35v (C981,C982) because the HD series doesn't include a 2200uF and the (1) 470uF 16v, which was out of stock in the HD series at the time of my order. I substituted the Panasonic FR and FM series, respectively.

Actually, the Panasonic FR and FM series (which are very similar)...

Re: Dynex DX-LCD37 Bad Caps!

There are people here!

Hopefully I'll have the caps in by Friday or Monday and will be able to post an update. I may try to post the part list sooner, as it was a fair bit of homework selecting the right ones, and it may be useful to someone else even if it doesn't solve my issue. The 715T2512-2 power supply seems to be used in a lot of TVs from this era, so I probably won't be the only one looking to re-cap one.

Re: Dynex DX-LCD37 Bad Caps!

FWIW the Nichion HD series seems to be the ideal replacement for the Elite ED series. The dimensions are pretty much the same for all values and the ESR and ripple current is considerably better in the Nichion HD than the Elite ED for every value I looked at.

I will stop talking to myself now...

Re: Dynex DX-LCD37 Bad Caps!

Possible success!

I haven't actually fixed it yet, but when I used my DC load to test the 24v supply it dropped out of regulation after a few minutes at 2 A...I'm assuming 2A is appropriate. I also heard the classic high frequency screech just before it dropped out.

I'm going to re-cap the low voltage side of the power supply completely and see how that goes. Again, I tested each of the capacitors already, but the two big 2200uF caps on the 24v supply got missed the first time, I tested them after my experiment with the...

Re: Dynex DX-LCD37 Bad Caps!

Hello, this is my first post.

I am a reasonably experienced tech, but not with TVs, and have the same problem as described in this thread. I have already spent a fair bit of time troubleshooting and have determined the following:
[LIST][*]The power supply is producing the correct voltages (5V standby, 12v and 24v when on)[*]I have checked the ESR of all of the electrolytic caps on the power supply and all of them seem reasonable (according to the classic Bob Parker chart)...they are all elite brand caps, ED series on the LV side...