Chimei DTC-37MK - solid red light

[VaNS]

So, I have this 37" LCD TV that just stopped working. I can't seem to power it on via Panel or Remote (by that I mean, trigger it to power on). I'm not sure if it's in standby mode, but when plugged in it only gives a solid red light in the front panel.

it seems this LCDTV shares the same qualities as a Maginnovision, Element.
Apparently the Mainboard was/is notorious for shorting if you plug something into a VGA port. So, I figured.. replace the mainboard and this being said I ordered a whole control box from shopjimmy ... plugged it in andddddd
same problem. solid red light. sooo this has be a bit baffled. Maybe LCD Panel completely dead? I was thinking but even if it was it would still attempt to power up wouldn't it?

it almost seems like it's something very simple that I'm missing.

[PlainBill]

Re: Chimei DTC-37MK - solid red light

So, I have this 37" LCD TV that just stopped working. I can't seem to power it on via Panel or Remote (by that I mean, trigger it to power on). I'm not sure if it's in standby mode, but when plugged in it only gives a solid red light in the front panel.

it seems this LCDTV shares the same qualities as a Maginnovision, Element.
Apparently the Mainboard was/is notorious for shorting if you plug something into a VGA port. So, I figured.. replace the mainboard and this being said I ordered a whole control box from shopjimmy ... plugged it in andddddd
same problem. solid red light. sooo this has be a bit baffled. Maybe LCD Panel completely dead? I was thinking but even if it was it would still attempt to power up wouldn't it?

it almost seems like it's something very simple that I'm missing.

Pictures.

The obvious test is to determine if the main board is generating the signal to turn on the main power supply (since you have a red led, the standby supply is good). The signal is probably labeled PS_ON, or something similar.

If you expect any more help, take three pictures - one overall shot of the back of the TV to establish where everything is. A second shot of the power supply, showing the output connectors. And a third shot of the main board. Sharp and well lit is important.

For best results make the pictures at least 1000 x 1000 pixels, but not over 2000 pixels. Attach them using 'Manage Attachments' - below the text entry area.

PlainBill

[VaNS]

Re: Chimei DTC-37MK - solid red light

Pictures.

The obvious test is to determine if the main board is generating the signal to turn on the main power supply (since you have a red led, the standby supply is good). The signal is probably labeled PS_ON, or something similar.

If you expect any more help, take three pictures - one overall shot of the back of the TV to establish where everything is. A second shot of the power supply, showing the output connectors. And a third shot of the main board. Sharp and well lit is important.

For best results make the pictures at least 1000 x 1000 pixels, but not over 2000 pixels. Attach them using 'Manage Attachments' - below the text entry area.

PlainBill

Ok, I'll look around for it. I'll be doing it with the original control box as I don't want to mess with the warranty on the one I just ordered.. which is said to be pulled out of a working LCDTV (but who knows).

I've pretty much torn the LCDTV apart right to the panel for testing. (I'm not great with a multimeter but I know a bit)

Any help on this is appreciated and thank you in advance as I've seen you help a few people on this site with their issues.

[VaNS]

Re: Chimei DTC-37MK - solid red light

Attached are.. well the frame.

connectors that lead into a serial port of some sort which connects to the mainboard.

the inverter and the mainboard.

--

I took a picture of the connector that leads to the mainboard from the power supply. I couldn't find PS_ON but would any of these be it? I took this picture through a lit magnifying lamp so if you need any close close ups feel free to direct me.

this is all a learning experience for me.

[tom66]

Re: Chimei DTC-37MK - solid red light

It looks as if that Panasonic cap just down from the main output connector is bulged.

I've dealt with this supply before with the same problem. The fault was the uppermost two capacitors next to the grey transformer. But you have replaced them.

Also something to check: While it is plugged in, try pressing down on the main board, near the input connectors, and seeing if the TV will then switch on.

[PlainBill]

Re: Chimei DTC-37MK - solid red light

Attached are.. well the frame.

connectors that lead into a serial port of some sort which connects to the mainboard.

the inverter and the mainboard.

--

I took a picture of the connector that leads to the mainboard from the power supply. I couldn't find PS_ON but would any of these be it? I took this picture through a lit magnifying lamp so if you need any close close ups feel free to direct me.

this is all a learning experience for me.

Usually at this point I'm complaining about the poor pictures; these are excellent. You deserve special recognition for the last one.

5VSB should always be live (5 volts) when the power supply is plugged in; STB is the control line. Because they call it STB, it may turn the power supply off when high - I've encountered that a few times.

And note tom66's comments.

PlainBill

[tom66]

Re: Chimei DTC-37MK - solid red light

Usually at this point I'm complaining about the poor pictures; these are excellent. You deserve special recognition for the last one.

5VSB should always be live (5 volts) when the power supply is plugged in; STB is the control line. Because they call it STB, it may turn the power supply off when high - I've encountered that a few times.

And note tom66's comments.

PlainBill

This power supply is very odd. It seems to generate 5V, 12V etc. all while in standby. When turned on, the 24V rail starts up; that powers the inverters and audio output. Seems a bit of an odd way to do it.

[VaNS]

Re: Chimei DTC-37MK - solid red light

So testing the voltages out of the connector leading to the mainboard.
-5VSB was a steady 5.23V
-STB was a steady 5.06V
-Applied pressure to the mainboard near the input connector while attempting to turn it on (no dice).

I figured the STB would show some fluctuation if I attempted to turn on the TV; am I to assume this is correct?

I'm starting to think both the remote, and my key controller board are both broken but that's just crazy talk maybe. The remote is definitely sending out an IR signal (I have an IR receiver for my computer that lights up for any IR device pointed at it). As for the key controller board has no actual buttons on it and is pressure sensitive of some sort (200-700-KF371CH) so I can't physically tell if I'm actually hitting the button.

Because I have installed a second control box and same issue occurs. Again leaves me baffled.

[tom66]

Re: Chimei DTC-37MK - solid red light

Do you have, or can you acquire a 1kohm resistor?

[VaNS]

Re: Chimei DTC-37MK - solid red light

Do you have, or can you acquire a 1kohm resistor?

yup, got one here.. what should I do?

[VaNS]

Re: Chimei DTC-37MK - solid red light

k so I was really unsure what to do with the 1kohm resistor so I went ahead and googled some testing via 1k ohm resisted and found this set up to test the IR Receiver via LED and 1K ohm resistor and went ahead and did it using well... a breadboard, LED and 4 AA batteries.

so... nothing wrong with the receiver that's for sure, but there is seriously something a bit squirrely about how this TV starts up. I'm definitely missing something.

I'm honestly willing to try about anything. In terms of equipment or components.. I'm trying to fix this TV for my parents and they run their own little electronics assembly company so there's tons of common components laying around.

[PlainBill]

Re: Chimei DTC-37MK - solid red light

Since STB does not change, there is a problem with the main board. At this point I usually suggest checking any fuses and LDO regulators on the main board.

PlainBill

[VaNS]

Re: Chimei DTC-37MK - solid red light

This power supply is very odd. It seems to generate 5V, 12V etc. all while in standby. When turned on, the 24V rail starts up; that powers the inverters and audio output. Seems a bit of an odd way to do it.

I actually went ahead and did a reading on the connector afterwards and you're right.

24VAMP read 23.7V
12V read 10.9V

this is still in standby I guess :S

Since STB does not change, there is a problem with the main board. At this point I usually suggest checking any fuses and LDO regulators on the main board.

PlainBill

ok, will look into that.