IC Number on DPS-286 AP/RDENCA336WJQZ Sharp power board

[i-didnt-start-the-fire]

Re: IC Number on DPS-286 AP/RDENCA336WJQZ Sharp power board

I pulled 6 little orange and black diodes off another board to solder one in thinking they were all the same
Did I mention I am a novice...
But decided to zoom in with a photo to see if there were any markings and noticed the one I removed was marked with TZX 15B
I checked the others 3v3 6v8 16B

I was going to ask here if I could use the 16B, but decided to just put the 16v in. It worked What the potential issues with this decision?
Do you think I need to change this diode to 15v or one that you mentioned (D7905)
i.e."7.5V should be OK or 12V 1/2W will be more than enough"

[i-didnt-start-the-fire]

Re: IC Number on DPS-286 AP/RDENCA336WJQZ Sharp power board

My other question is hard to word and may be hard to answer because of this.
I want to know how you worked it out.
There was low resistence on the ENUV PIN. I would have come to the conclution that the resistance through the IC was bad.
You knew there was something else on the board that was lowering the resistance.
I know this is probably electronics basics to some but it was enlightening.

[i-didnt-start-the-fire]

Re: IC Number on DPS-286 AP/RDENCA336WJQZ Sharp power board

I have found the answer to my question immediately above.
I have a copy of Justine Youngs Troubleshooting and repairing switch mode power supplies which I am reading through.
He explains that there is one or more high Ohm startup resistor between the primary 300VDC caps of and the power IC. If this shorts or opens it will cause No-Power problems and sometimes intermittent power problems.

[alexrb2020]

Re: IC Number on DPS-286 AP/RDENCA336WJQZ Sharp power board

R7914 is the 2.2 OHMS FUSIBLE resistor 1/4W (or 1/2W, you have to measure the dimension) for supplying B+ to run the STBY power supply section, (you can use 2.2 Ohms MOX type which is Flame proof )that will blow open when that SMPS IC for the STBY power supply shorted out. R7918 is still OK?
Sharp RDENCA235WJQZ (DPS-304BP-1) Power Supply Unit
http://www.shopjimmy.com/sharp-rdenc...pply-unit.htm#

Hi,
I have one power supply exactly like that one from your picture.
if you take a look on the schematic diagram (attached), you have the PD connector, on right hand side at the bottom (right corner) of the schematic diagram.
I've checked the stand by voltage, which is 5 Volt, at pin 8 on PD connector.
if you connect the pin 4 (PS_ON) to pin 8, the power supply starts and all the voltages are present and correct.
but, the TV doesn't start.
any thoughts where I should take a look? I assume is something wrong on TV, not on the power supply.
thank you.

[i-didnt-start-the-fire]

Re: IC Number on DPS-286 AP/RDENCA336WJQZ Sharp power board

I am an ameteur so I will just ask some questions to get our troubleshooting juices flowing while we wait for the experts.

"...the TV doesn't start."
does the set move out of standby with the remote but the screen does not show anything and there is no sound or nothing happens.

"...all the voltages are present and correct."
Does that include the other connecters like the 60v inverters on LA_R and LA_L, and the 12v etc.

[nomoresonys]

Re: IC Number on DPS-286 AP/RDENCA336WJQZ Sharp power board

Hi,
I have one power supply exactly like that one from your picture.
if you take a look on the schematic diagram (attached), you have the PD connector, on right hand side at the bottom (right corner) of the schematic diagram.
I've checked the stand by voltage, which is 5 Volt, at pin 8 on PD connector.
if you connect the pin 4 (PS_ON) to pin 8, the power supply starts and all the voltages are present and correct.
but, the TV doesn't start.
any thoughts where I should take a look? I assume is something wrong on TV, not on the power supply.
thank you.

With the jumper in place are you getting voltage on pin 5 AC_DET? should be around 3 volts when tv is working correctly.