Sceptre x20g-NagaIII (x20wc-gamer) issues.

[Flababa]

I've been trying to find information as to what may be wrong with this thing, but I haven't found anything that fits the symptoms I'm experiencing.

Normal operation:

• Connect DVI / D-sub cable to PC.
• Plug display power in.
• Press power button.
• Sceptre logo appears, and fades out.
• Sceptre logo on front of unit blinks red.
• Display detects PC / Laptop / Etc, picture is displayed.
• Sceptre logo on front of unit turns blue.

Current operation:

• Connect DVI / D-sub cable to PC.
• Plug display power in.
• Sceptre logo on the front of the unit turns red- Solid. No blinking.
• No picture. No menus. Unit will not turn off by pressing the power button.

I was using the monitor one day, then suddenly red lines from top to bottom on the center of the screen (but not spanning the entire screen) showed up, and then the display went black. No backlight, nothing.

I pulled the unit apart, and can't for the life of me find something obviously (visually) wrong. I've searched for similar symptoms, but haven't found anything at all. Attached are photos of the power and video board from the unit. I'm an amateur at best when it comes to repair theory. I can solder and follow instructions quite well, but that's about where it ends.

The capacitors look to be intact. No burn marks around any of the components. Attached is a few photos I took.

Anyone have any ideas for me? This monitor has a twin on my desk that's getting lonely. =/


Thanks in advance for any help you can offer!

[PlainBill]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

First step, there are two connectors on the lower right corner of the picture of the back of the power supply / inverter card. Note that some pins are labeled Gnd, 5V, 12V. With DMM measure the voltage from GND to 5V (should be 5 volts) and from Gnd to 12V (should be 12 volts). If either of those are missing, it's most likely a problem with the power supply, disconnect the logic card to be sure (turn off power before disconnecting it!!!).

Second step, the logic card. There are several voltage regulators, U7, U9, U11, and U12. In the 'normal' orientation the tab is at the top, the three legs are at the bottom. The legs are numbered from 1 to 3 from left to right. Use one of the mounting tabs of CN2 as ground. Measure and report the voltage on each leg of U7, U9, U11, and U12. Also report the part number of each IC.

PlainBill

[Flababa]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

Tested the 5v and 12v lines. All showing normal.

Voltage Regulators:

U7 - AXH 548

• 0.0
• 1.8
• 3.8

U9 - ABF 512

• 0.0
• 3.3
• 5.1

U11 - ABF 512

• 0.0
• 3.3
• 5.1

U12 - AKE 407

• 0.0
• 2.5
• 4.5

Hopefully I reported this properly. Let me know if not, and I'll fix it. If I'm going to learn as I go, I wanna do it right.

[jetadm123]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

Tested the 5v and 12v lines. All showing normal.

Voltage Regulators:

U7 - AXH 548

• 0.0
• 1.8
• 3.8

U9 - ABF 512

• 0.0
• 3.3
• 5.1

U11 - ABF 512

• 0.0
• 3.3
• 5.1

U12 - AKE 407

• 0.0
• 2.5
• 4.5

Hopefully I reported this properly. Let me know if not, and I'll fix it. If I'm going to learn as I go, I wanna do it right.

Typically, the outputs are 1.8V or 3.3V. U7,9 and 11 look good. U12 output of 2.5V seems low or high, since I'm really not sure what type of regulator the AKE 407 is. The part number AKE 407: is there any other number like 18 or 33 stamped on it?

[PlainBill]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

Tentatively, I would say those voltages are correct. 3.3, 2.5, and 1.8 volts are all standard voltages for processors; 2.5 is rarer, but is (I believe) used for the memory interface.

What is slightly interesting is the input voltages seem to be slightly 'off' from what I would expect.

PlainBill

[Flababa]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

Yeah, there isn't any other information printed on the component itself. Here's a slightly better photo of it, but I don't see it being of much help.

This is probably the best I can do with my little camera. =/

[Flababa]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

It seems that here in this thread, they have the same board, but the printing on U12 doesn't seem to match up. I can't quite make out the numbers:
https://www.badcaps.net/forum/showpo...18&postcount=1

Then here, the wire on the bottom crossing that connection...is going to a different spot on my board:
https://www.badcaps.net/forum/showpo...21&postcount=3

It appears to be the same board that I'm using.

I can't make any sense of it really. Anyone? haha

[PlainBill]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

It seems that here in this thread, they have the same board, but the printing on U12 doesn't seem to match up. I can't quite make out the numbers:
https://www.badcaps.net/forum/showpo...18&postcount=1

Then here, the wire on the bottom crossing that connection...is going to a different spot on my board:
https://www.badcaps.net/forum/showpo...21&postcount=3

It appears to be the same board that I'm using.

I can't make any sense of it really. Anyone? haha

The voltage regulators appear to be working. The red lines could indicate a failure of the processor on the logic card. While it is possible it is another component on the board, in my opinion it is unlikely . The best approach would be to find a replacement logic card.

PlainBill

[Flababa]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

I was afraid you'd say that.

Guess I'll have to hunt one down. (unlikely I'll find one. haha)

Thanks for all your help!

[jetadm123]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

Since you have only one electrolytic cap (C117) on the logic card, I would go ahead and change it. I've had weird problems caused by dried out caps on the logic card. Since the size of the logic card is generally much smaller/compact than the power board, manufacturers tend to use physically smaller size caps. The Gateway monitor I worked on had several 220uf caps that were super small in size. Because of their small size, they dried out very quicky. At this point, you've got nothing to lose.

[Flababa]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

Hrm. While removing the capacitor from the logic board, I think I found a burned component. Not sure how I missed it before.

C118 on the board. One of the orange / yellow components. Top-right of both photos, right next to U11.

Think that could have something to do with it? I don't even know what that thing is! haha


Text reads (far as I can tell):

A226J
93AF3

[jetadm123]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

C118 does look a little discolored, but it's hard to tell because of the lighting. It's a cap because of the "C" in C118. These type of caps seldom fail on their own and if it is burned out, it might have been caused by another component shorting out.

As for the A226J. Not sure what the "A" stands for, but

226J = 22000000pf = 22,000nf = 22uf, where "J" = +/- 5% tolerance

[Flababa]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

Was actually just taking photos. This is after cleaning it off to make sure it wasn't just 'dirty' from whatever.

It's actually a sunny day today, so I can follow the guide. haha


The only writing on it I could make out is what I posted above:
A226J
93AF3

Two lines. The A is superscript it seems, it that matters.


http://i.imgur.com/p0z0x.jpg isn't resized.

[jetadm123]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

See post #12 for cap value. Try tracing the path of C118 to see what each end of the cap is connected to, maybe D25, D26, U11?

[Flababa]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

Yeah, from what I gather the A relates to the physical size of the unit. (http://www.scienceprog.com/few-words...nt-components/)

Now, how does one obtain the rated voltage from something like this?

Far as tracing where it goes: It seems to eventually run under the board? (maybe?) It's hard to tell since I have limited experience doing this..but just at a glance it seems to contact D25, D26, U11, then shoots down to several others and possibly the back via the pins above it? Could connect with C119, R110 etc.

Think it would be easier to replace both that, and the capacitor I've already removed to see if it works / blows out again? I did use the display a lot. At least 8 hours a day, seven days a week for ~3-4 years. Give or take. (home 'office')

I only ask because we're going well beyond my troubleshooting experience at this point. I'm not above having my hand held, but I won't expect it, is what I mean.

[jetadm123]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

Since the logic card seems to run off of 5 volts, my guess at a voltage for the cap would be at least 10V or greater. What was the voltage of C117 rated at? You can probably use the voltage of C117 as a guide.

[Flababa]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

C81 - 3.3
C18 - 5.1
C71 - 1.8
C92 - 3.3
C72 - 5.1
C118 - 5.0 - Burned
C107 - 2.5

That's what I got from each individual of that type. I'm not sure how I'm supposed to rate these. Meaning, how much voltage over what they're using SHOULD they be able to handle?

Also, any idea as to where I could order this part without buying 100 of them? :s

[jetadm123]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

C81 - 3.3
C18 - 5.1
C71 - 1.8
C92 - 3.3
C72 - 5.1
C118 - 5.0 - Burned
C107 - 2.5

That's what I got from each individual of that type. I'm not sure how I'm supposed to rate these. Meaning, how much voltage over what they're using SHOULD they be able to handle?

Also, any idea as to where I could order this part without buying 100 of them? :s

What was C117 rated at? 10 or 16V? I would use that as the benchmark for voltage selection and would only replace C117 and C118, since the logic board may have more serious problems as suggested in post #12. If you're in the USA try digikey.com and select USPS shipping for the lowest ship rate.

[Flababa]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

I must be blind. Looking over and over expecting to find a surface mount component labeled C117.

16v 470uf. haha

[Flababa]

Re: Sceptre x20g-NagaIII (x20wc-gamer) issues.

Hrm. I can't seem to find either on Digikey. =/

I think I found C117, but C118 is being problematic. I can't find anything matching the specs from this thread. 10v or 16v, I can only find one rated with 5% tolerance. Checked Digikey to find nothing. Mouser is closer, but just not there.