Sceptre X9G-Komodo II* blinking power light

[hennegan]

Re: Sceptre X9G-Komodo II* blinking power light

1. What brand(s) are the caps?

They are mostly Elite caps from what I can tell.

The first two are easy to identify - they are the Schottky rectifiers in the power supply secondary. If you have normal output voltages and they don't get unreasonably hot, they are good. The third is the power FET in the power supply. If this were bad the supply wouldn't work at all.

Spot-on! Amazing. I wish I had tested rectifiers/FET before removing. At this point, I'd rather put in new ones while I have them out.

Correction on D104: Identifier is actually FCQ10U06 I believe.

Given the attached datasheets, would these be correct?
D104: http://search.digikey.com/scripts/Dk...e=RB215T-60-ND
D105: http://search.digikey.com/scripts/Dk...R20100CTGOS-ND

The third is the power FET in the power supply. If this were bad the supply wouldn't work at all.

This is good to hear, as it's relatively expensive where I can find it!

[PlainBill]

Re: Sceptre X9G-Komodo II* blinking power light

Thanks for providing the pictures. The first two are easy to identify - they are the Schottky rectifiers in the power supply secondary. If you have normal output voltages and they don't get unreasonably hot, they are good. The third is the power FET in the power supply. If this were bad the supply wouldn't work at all.

Your troubleshooting has shown the problem is on this board. That makes it easy to eliminate the CCFLs and their wiring. In simple terms, the problem is either an unstable supply (bad caps), bad drive voltage to the CCFLs, or a problem with the protection circuit.

1. What brand(s) are the caps?

2. Hook the monitor together, connecting only 1 CCFL. Turn the monitor on. Do you get a flash from the CCFL, and how bright was it? Disconnect that CCFL, and hook another one to it's connector. Turn on the monitor. Do you get a flash from that CCFL, and was it as bright as the first? Repeat, testing each output by itself. If all CCFLs gave the same brightness, it is either the caps or the sense (protection) circuitry.

PlainBill

[hennegan]

Re: Sceptre X9G-Komodo II* blinking power light

Thanks again Retiredcaps It's definitely not a CCFL issue as the display works fine with a working inverter board, but the more I read that thread, the more I feel this board is showing symptoms of a defective MOSFET.

I pulled all 3. I'd like to test them, but not sure if my digital multimeter could do it. Would you be able to help ID them for replacement? (pics attached)

D104:
N 4 G
FC010U06 (I think)
174
(No clue on this one)

D105:
N 4 G
FCH10U10
056
(I think the attached PDF is correct?)

Q101:
P 01
K2645
4N
I think this is it, but the 3rd row does not match:
http://cgi.ebay.com/200353403075

[retiredcaps]

Re: Sceptre X9G-Komodo II* blinking power light

The only somewhat aggravating thing is I can hear a faint high-pitch noise that I can't pin-point, so I'm guessing this one will need some other caps replaced after some time.

Any suggestions on where to start?

The high pitched noise could be a small capacitor that is goind bad. It might be the one next to the largest main filter capacitor and/or SMPS transformer.

Go back to post #36 since you have 2 identical monitors.

[hennegan]

Re: Sceptre X9G-Komodo II* blinking power light

Happy new year all and thanks RetiredCaps! Good news: I got one of my power boards working.
Replaced RT101 thermistor with this:
http://search.digikey.com/scripts/Dk...me=495-2092-ND
Replaced DB101 diode bridge with this:
http://search.digikey.com/scripts/Dk...e=KBP206GDI-ND
Also had to replace F101. The only somewhat aggravating thing is I can hear a faint high-pitch noise that I can't pin-point, so I'm guessing this one will need some other caps replaced after some time.

I'm happy to finally have worked back to my original problem from my original power board.
It's symptoms:
Panel works normally for about a half-second, then goes black; power indicator is still on. When the problem first started, I found that after turning it off/on a few dozen times, I would get lucky and it would stay on. I shined some bright lights on the panel to see if I could tell if it was just the CCFLs, but I could not see any indication that the display signal was getting to the screen. So far, only replaced C105 (large cap) as I noticed some leakage around the positive lead. Pics of that board are attached.
I wish I had more evidence to go on. Any suggestions on where to start?

[retiredcaps]

Re: Sceptre X9G-Komodo II* blinking power light

I set my multimeter to 200 Ohms to test the DB: 1-2, 1-3, 1-4 read 1 (no change); all others read .2. I tested the same DB on my original, defective board, and it was 1 across the board (good right?).

"1" on the left hand sides indicates out of range or infinite. The DB should test "1" for all combinations. If it reads 0.2 ohms, it is definitely shorted and bad.

[hennegan]

Re: Sceptre X9G-Komodo II* blinking power light

Holy cow--this is a gold mine of info--thank you RetiredCaps.

I set my multimeter to 200 Ohms to test the DB: 1-2, 1-3, 1-4 read 1 (no change); all others read .2. I tested the same DB on my original, defective board, and it was 1 across the board (good right?). Unless my multimeter is bad (entirely possible after my last mis-hap), I think that may be the culprit. I'll order those and read up on those parts, then post an update after replacement.

Symptoms of the original board: Panel works normally for about a half-second, then goes black; power indicator is still on. When the problem first started, I found that after turning it off/on a few dozen times, I would get lucky and it would stay on. I shined some bright lights on the panel to see if I could tell if it was just the CCFLs, but I could not see any indication that the display signal was getting to the screen. So far, only replaced C105 (large cap) as I noticed some leakage around the positive lead. I am confident the problem lies on the power board as I tested with my 1 working X9G-Naga III, and ordered a replacement that worked as well... until I broke it.

[retiredcaps]

Re: Sceptre X9G-Komodo II* blinking power light

-RV101

RV = Varistor

See designations at

http://en.wikipedia.org/wiki/Electro...e_designations

[retiredcaps]

Re: Sceptre X9G-Komodo II* blinking power light

Obviously, I need to replace RT101 on the new board. It's roughly 10mm across; leads are 5mm apart; printed text on it is "SCK 103".

Decoder ring

[retiredcaps]

Re: Sceptre X9G-Komodo II* blinking power light

- I replaced C105 on my original board, but to no avail. I'm not sure what to try next at this point. Since there is no other defective part visible under my magnifier, anything I would try to replace would be a shot in the dark.

You will have to update what is wrong with the original board again.

- I also replaced F101 on the new board that I destroyed by accidentally shorting 2 joints near the AC plug. When I tested that, I blew RT101. An image is attached; could anyone tell me what this is?

I believe RT stands for resistor thermal.

I removed L101 (transformer?) to take better pictures of possible culprits:
-C101
-C102
-C103
-RV101
-DB101

Would anyone be able to suggest part(s) to start with on either board, and possibly ID them?

L = inductor.

DB = diode bridge. Number the pins 1-4. You can test this without removing it from the board. Put your multimeter on 200 ohms (if manual). With power off and lcd unplugged, measure the resistance between 1-2, 1-3, 1-4, 2-3, 2-4, and 3-4. Any reading less than 30 ohms suggests this is shorted.

The blue caps rarely go bad and I believe they visibly crack if they do. Same for the grey square one.

[hennegan]

Re: Sceptre X9G-Komodo II* blinking power light

Hi RetiredCaps & Alexanna!

- I replaced C105 on my original board, but to no avail. I'm not sure what to try next at this point. Since there is no other defective part visible under my magnifier, anything I would try to replace would be a shot in the dark.

- I also replaced F101 on the new board that I destroyed by accidentally shorting 2 joints near the AC plug. When I tested that, I blew RT101. An image is attached; could anyone tell me what this is?

- For this newer board, I am thinking there must be a defective component in the circuit between this new damaged part and the AC plug. I removed L101 (transformer?) to take better pictures of possible culprits:
-C101
-C102
-C103
-RV101
-DB101

Would anyone be able to suggest part(s) to start with on either board, and possibly ID them?
Obviously, I need to replace RT101 on the new board. It's roughly 10mm across; leads are 5mm apart; printed text on it is "SCK 103".

Thanks for coming back!
-Will

[alexanna]

Re: Sceptre X9G-Komodo II* blinking power light

What did end up getting to replace this diode?

The marking s4 looked closest to the part, using the smd code book. A part of very similar specifications to 1ss389 was used as a replacement .However I never was able to find what was causing the transistors to short ,so I don't know if I used the correct diode.
Al.

[retiredcaps]

Re: Sceptre X9G-Komodo II* blinking power light

the marking on it are s4 3b.

What did end up getting to replace this diode?

[hennegan]

Re: Sceptre X9G-Komodo II* blinking power light

Update:

After further investigation, F101 is this fuse:
http://search.digikey.com/scripts/Dk...&name=F3298-ND
Don't know why I didn't realize this earlier since it's printed right on the board :/

C105 (the big cap) is 400v, 100uF. I believe this is a comparable part:
http://search.digikey.com/scripts/Dk...me=565-1469-ND
None in stock @ digikey unfortunately, but found in-stock @ Mouser:
http://www.mouser.com/ProductDetail/...LDY23Ggw%3d%3d

I'll order & install these and post another update.

[hennegan]

Re: Sceptre X9G-Komodo II* blinking power light

Hi again all,

Thanks in advance to anyone who returns to this thread to refresh their memories & help out. I'm sorry it has been almost 2 months since my last post here--quite a bit has happened (family/medical stuff, increased load @ work due to layoffs, etc.).

First off, a related & somewhat funny story: I broke down & purchased a replacement power board for my monitor from Sceptre for $65 shipped (rip-off, I know). I now had a working original, a working replacement, and a defective original. The new IC board had the same markings, but their were some discrepancies in the components (larger caps, some appear to be omitted, etc; pics attached after the break). Most of the voltage readings I could get were the same as the original board.

In the process of testing, I lost focus and let one of my multimeter leads slip. There was a bright flash and a loud bang that freaked out the wife & dog across the house. When I got my vision back, I realized that I had fried something on my new, expensive board.

Before continuing work on the original, I'd like to fix the brand new one (since the problem is a tad more obvious).

Front & back images of the new & old boards are attached. The damage (pictured) on the new board seems to be on F101, right above the power plug (pics of the component, and its through-holes after removal).

I'm pretty sure this is a fuse? I could strip more of the insulation off of it if it would help ID its rating, or is there another way to determine that?

Other, less pressing information:
- D1, D2, D4 all read .44 volts, and D3 reads .21 volts on old & new boards. The new board looks to be missing D2 and D5 (along the top of the back pics), but doesn't seem to affect operation.
- C105 (the big cap) read a steady 155 volts on the new board, when it worked (unless i didnt test long enough). On the old one, it starts around 160 volts, then gets up to 200 volts or more after a minute or so of juice.
- The 4 large caps standing up along the right side, from bottom to top, are C114, 115, 117, 118. C117 and 118 were both 5 volts on old & new boards. C114 and 115 were 14 volts on the old one and 17 volts on the new. Hard to tell from pictures, but 114 and 115 are the same size as 117 and 118 on the new board; they are slightly shorter on the old board.

In short, for those who find this forum from Google because you have the same problem, you could probably get a replacement board from Sceptre if you ask and want to pay for it. You'll need the serial from a barcode sticker on one of the vertical metal pieces.

I am still eager to fix my (now 2!) IC boards, hopefully before my lone working Sceptre LCD dies!

Happy Thanksgiving to all.

-Will

[retiredcaps]

Re: Sceptre X9G-Komodo II* blinking power light

but if anyone has any threads bookmarked that has some beginner tips (iron temp, solder type, etc.)

I like Curious Inventor videos for soldering

http://www.youtube.com/watch?v=I_NU2ruzyc4

http://www.youtube.com/watch?v=3NN7UGWYmBY

[hennegan]

Re: Sceptre X9G-Komodo II* blinking power light

Those pins I have shorten with red should not be shorten.

Thank you Mistery--that is a very helpful image.

And thanks as well to Alexanna. I have never soldered anything on such a small scale (usually just home wiring with a Weller gun), but will give it a shot. I need to get a more precise soldering tool. I'll search the forums, but if anyone has any threads bookmarked that has some beginner tips (iron temp, solder type, etc.) I'd be grateful; don't mean to stray from this thread's topic though.

[alexanna]

Re: Sceptre X9G-Komodo II* blinking power light

Thank you Jetadm123! I guess symptoms would help--can't believe I neglected to post those too.

When the screen is powered on with a signal (VGA or DVI), The screen displays for a half second, then goes black. The power LED remains on after the panel goes black. If the screen is turned off/on, the screen comes on again for a half second. I don't believe it is [just?] the CCFLs, as I can see nothing on the panel under a bright light source when on. When this first started, I found that if I power-cycled it enough, it would eventually stay on as long as my PC never turned off the displays. This worked for days at a time until I could get a good used 5:4 ratio 19" replacement.

No blinking power light though; I still posted here though because I'm guessing the problem roots around the same LM004 power board all these LCDs share.

The first thing I checked was fuse F1, hoping it was something simple. Good continuity there though.

Will check connectors and filter cap voltage and report back, though may take a week or so.

For the moment I have put my monitor power supply/inverter on the back burner.
You are lucky as retiredcaps suggests having two identical monitors for your trouble shooting.
Some things I noticed with my monitor, was being able to seeing the desktop with the use of a flash light, I could not. I had to power on one ccfl with a ccfl tester to see the desktop.
I would suggest carefully checking the solder joints in the area of the inverter coils particularly the two poly caps also reflow the solder at the two inverter coils. And checking the Q transistors for shorts, If you have a desktop visible after your back lamps go out.
Al.

[mistery]

Re: Sceptre X9G-Komodo II* blinking power light

Thank you Jetadm123! I guess symptoms would help--can't believe I neglected to post those too.

When the screen is powered on with a signal (VGA or DVI), The screen displays for a half second, then goes black. The power LED remains on after the panel goes black. If the screen is turned off/on, the screen comes on again for a half second. I don't believe it is [just?] the CCFLs, as I can see nothing on the panel under a bright light source when on. When this first started, I found that if I power-cycled it enough, it would eventually stay on as long as my PC never turned off the displays. This worked for days at a time until I could get a good used 5:4 ratio 19" replacement.

No blinking power light though; I still posted here though because I'm guessing the problem roots around the same LM004 power board all these LCDs share.

The first thing I checked was fuse F1, hoping it was something simple. Good continuity there though.

Will check connectors and filter cap voltage and report back, though may take a week or so.

The same problem was with mine monitor.

Can you try first disconnect upper lamps from board, and then start monitor, and if you see picture for the second the problem is on the lower side of the board, you can disconect lower lamps and comfirm this. Or oposite. When you find the side you shoud remove transistors and check oposite legs for shorts. If one is short this one is bad.

Is one is short replace boath. Do not try with ony one becouse is will kill the good one.

Also sou shoud check
D1, D2, D3, D4 (It shoud have same mesures),
ZD1, ZD2 (also shoud be the same.)

Those pins I have shorten with red shoud not be shorten.

[retiredcaps]

Re: Sceptre X9G-Komodo II* blinking power light

Also, I have an identical working model of this LCD.

Okay, having 2 identical monitors will make this easier. Rather than repeat myself, see this active current thread ... (start with post #33)

https://www.badcaps.net/forum/showth...?t=7662&page=2