Samsung 2493hm blue light blinking

[kylejjjjj]

OK i have looked at almost all of the posts on this monitor i got it for free so i would like to fix it because they would rock free 24 in hell ya
OK but here is what i think i know
the caps look good but i will replace them anyway but i don't know witch need replacing

i get a blue blinking light
measuring what i think were voltage regulators on the logic board i got odd results voltage on both leads on both regulators would reach 3 or 5 volts but synced with the blue light the voltage would drop so that leads me to think power supply going back to what caps to replace
any help would be great
thanks

[retiredcaps]

Re: Samsung 2493hm blue light blinking

i get a blue blinking light
measuring what i think were voltage regulators on the logic board i got odd results voltage on both leads on both regulators would reach 3 or 5 volts but synced with the blue light the voltage would drop so that leads me to think power supply going back to what caps to replace

Disconnect the main/logic board and see if you get stable 5V standby power first.

Good focused top down pictures of all your boards help us help you. See my sig file below and follow the instructions exactly.

[kylejjjjj]

Re: Samsung 2493hm blue light blinking

ok so i was not able to test but will be able to later today

here are the pics

[kylejjjjj]

Re: Samsung 2493hm blue light blinking

ok so i tested what i think is the right pin


pic with arrow provided




and i got a steady 5.22v

[retiredcaps]

Re: Samsung 2493hm blue light blinking

and i got a steady 5.22v

Okay, reconnect the main board. Is the corresponding 5V standby pin on the main board steady at 5.22V DC?

[kylejjjjj]

Re: Samsung 2493hm blue light blinking

no it drops down to something around 4 volts then i also hear a shock like sound come from the power board synced with the voltage drop

[retiredcaps]

Re: Samsung 2493hm blue light blinking

no it drops down to something around 4 volts

I can think of 2 possibilities although there could be more.

1) The standby 5V is failing under normal load.

2) Something on the main board is shorted and drawing too much current for the 5V standby rail to deliver.

[kylejjjjj]

Re: Samsung 2493hm blue light blinking

i believe its the first due to the strange noise coming from the power board but what should be done next im kinda new to this

[PlainBill]

Re: Samsung 2493hm blue light blinking

i believe its the first due to the strange noise coming from the power board but what should be done next im kinda new to this

Go to Radio Shack and buy the two-pack of #47 lamp 272-1110. Hook one between the 5V output and ground of the power supply. If the power supply puts out a steady 5 volts, the problem is the signal board.

PlainBill

[kylejjjjj]

Re: Samsung 2493hm blue light blinking

would a 12v 50 mA bulb due the trick?

if so with the 12v 50mA bulb connected it sat at 5.22v
if not i will buy one tomorrow




what would be the next step if there was a short on the main board

[jetadm123]

Re: Samsung 2493hm blue light blinking

would a 12v 50 mA bulb due the trick?

if so with the 12v 50mA bulb connected it sat at 5.22v
if not i will buy one tomorrow




what would be the next step if there was a short on the main board

Probably not, since you're testing the 5V output.

[newbie1]

Re: Samsung 2493hm blue light blinking

Hi,
I am not saying it is the same but just for your info, i have 2 of this main board drawing high current causing my Power board main fuse and a few other components to constantly blow. Link is here. Maybe you should follow Plainbill's suggestion using a 5V bulb.

Oh, while you are at it... If it is ok with you, are you able to help me measure the resistance (with power off) of the VDDC of IC300 (the big IC) on the main board to Gnd (screw of the main board).

I have yet to purchase the replacement of the main board because the RELIABLE choice vendor are limited. Plus it is not cheap for shipment to my country.

[kylejjjjj]

Re: Samsung 2493hm blue light blinking

ok well i will buy the right bulb then and also if you could link me a data sheet so i know what pin i would be more than happy to help but keep in mind that i do believe my main board has a short somewhere hopefully that wont effect what you need

[PlainBill]

Re: Samsung 2493hm blue light blinking

ok well i will buy the right bulb then and also if you could link me a data sheet so i know what pin i would be more than happy to help but keep in mind that i do believe my main board has a short somewhere hopefully that wont effect what you need

One point - there is nothing magic about the #47 light bulb. I wanted you to use something that handles a significant amount of current and was readily available. At one time Radio Shack carried a 10 ohm 5 watt resistor at most stores. That would have been ideal - we want to load the 5V supply at a respectable level. 50mA won't do it. 150 mA is better, but still lower than ideal. If you have a 5 -10 ohm resistor available, use that.

PlainBill

[newbie1]

Re: Samsung 2493hm blue light blinking

if you could link me a data sheet so i know what pin i would be more than happy to help but keep in mind that i do believe my main board has a short somewhere hopefully that wont effect what you need

You can refer to the PDF file in this post >> link. The PDF is the schematic diagram of the main board which you can also use with regards to your problem. Hopefully your Mainboard is not the culprit or even if it is, hopefully it is repairable.

I will just need your help on a resistance across either of the SMD capacitor marked C332, C334, C335, C336, C337, and C338. Mine was reading 30ohms one way & 100ohms when reversed. Which i am assuming that the IC300's on my mainboards are busted.

many thanks for your help.

[newbie1]

Re: Samsung 2493hm blue light blinking

Oops wrong thread. sorry