Tevii S660 USB Satellite Tuner for PC
I've got one of these little usb satellite tuners that's started to play up. I'm not quite sure where the problem is but I've narrowed it down to a couple of areas, and I'm including possibly more background than necessary on the off-chance it might help someone else in the future. And yes, I know that this is beyond economic repair. A new one is only £50 or so, but I just got curious.
First a bit of technical background (sorry if this is teachin your grandma to suck eggs stuff - I'm trying to keep it to the minimum)....
caryg
Member
Last Activity: 02-19-2014, 09:37 PM
Joined: 08-19-2009
Location:
-
lg 50ps3000 red haze
I'm trying to repair one of these LG plasmas which suddenly came up with the dreaded red haze - the picture has a red tint on most settings, apart from cinema when it is all green. Received wisdom seems to be that this is a fault with the high power transistors on the Z-SUS board, and that a kit like [URL="http://www.ebay.co.uk/itm/LG-50PS3000-ZSUS-REPAIR-KIT-Poor-Red-Picture-EBR55360601-EBR548636010-50PS3000za-/281139858292"]this one on ebay[/URL] has all the bits needed to fix it.
Now I don't like just buying random parts without actually knowing if they are faulty,... -
Re: plasma tv LG model 50PS3000-ZB, Z SUS board EAX 55361501
Probably too late for the O/P, but if anyone else has the same problem it's an IRS210614S... -
Re: YuSmart 209RP-H (aka Viewsonic JT229ZP6MR )White Screen
The green caps are indeed all Lelon, but the smudge is just an artefact on the photo. This is a particularly shiny PCB and it took a few tries to get a reasonably decent picture.
I've checked the power on all the pins of the main logic chip as specified on page 20 of that pdf I linked to. The ones that should have 3.3v going in read 3.28 on my meter, and the ones that should be 1.8v show 1.79. I listed the T-Con voltages that I can check in the first post, and I'm not sure where else to check there. Plus...Leave a comment:
-
Re: YuSmart 209RP-H White Screen
Reposted in the correct forum. Please reply [URL="https://www.badcaps.net/forum/showthread.php?p=233576"]over there[/URL] and not here.Re: YuSmart 209RP-H White Screen
Reposted in the correct forum. Please reply [URL="https://www.badcaps.net/forum/showthread.php?p=233576"]over there[/URL] and not here.Re: YuSmart 209RP-H White Screen
Reposted in the correct forum. Please reply [URL="https://www.badcaps.net/forum/showthread.php?p=233576"]over there[/URL] and not here.Leave a comment:
-
YuSmart 209RP-H (aka Viewsonic JT229ZP6MR )White Screen
(thread copied from this one posted by mistake in the TV forum - please reply here)
OK I know this probably ain't the best quality monitor in the world, but I got it non-working for almost nothing, and getting it going has turned into a bit of a personal challenge. It came totally dead, but after changing the power mosfet, a couple of resistors and the PWM I/C it now lights up (I guessed that the blown SM resistor in the first pic below read 471, and soldering a 470 ohm 1/4 watt resistor over the top seems to work), but I just get a white screen.
Now looking at... -
Re: YuSmart 209RP-H White Screen
D'oh, this was meant to be posted in the Troubleshooting Computer Displays forum. Can someone please move it.Leave a comment:
-
YuSmart 209RP-H White Screen
OK I know this probably ain't the best quality monitor in the world, but I got it non-working for almost nothing, and getting it going has turned into a bit of a personal challenge. It came totally dead, but after changing the power mosfet, a couple of resistors and the PWM I/C it now lights up (I guessed that the blown SM resistor in the first pic below read 471, and soldering a 470 ohm 1/4 watt resistor over the top seems to work), but I just get a white screen.
Now looking at [URL="https://www.badcaps.net/forum/showthread.php?t=17904&page=2"]this thread[/URL] on... -
Re: Manson 80W Constant Power Switching Mode Power Supply
I didn't bother posting any general pictures of the unit because there are lots [URL="http://naklojik.blogspot.com/2011/09/maplin-n27gg-80w-switching-bench-supply.html"]here[/URL] including [URL="http://3.bp.blogspot.com/-FLWzIsDzCRI/ToGv3mbWEwI/AAAAAAAAAFs/ZtV7bv_V4Ug/s1600/IMG222_r.jpg"]this one of the front of the unit[/URL] - if anyone would prefer me to upload a couple here to make the archive a bit more complete then just say and I'll do it.
The power switch on the front is a hard...Leave a comment:
-
Re: Manson 80W Constant Power Switching Mode Power Supply
The resistance across NTC1 when cold is 7-8 Ω and the voltage drop across there settles down to 0.05-0.1 when it has been running for a while.
I've pulled all the caps on the primary side to check the ESR and they all check out fine. That's not to say they won't get replaced once I've got it running, but I'm happy for the moment that they are not the trouble.
I tried swapping the bridge rectifier out for another but it made no difference.
I've pulled all the optoisolators...Leave a comment:
-
Re: Manson 80W Constant Power Switching Mode Power Supply
That APFC stuff is interesting. So presumably the efficiencies come about from being able to charge the smoothing capacitors a bit higher, so there's less need for big swings in draw from the mains when the load changes suddenly. Would I be right in concluding that the claimed improvements relate more to places that run on 110V than to those which run on 220-240V?Leave a comment:
-
Re: Manson 80W Constant Power Switching Mode Power Supply
Thanks for the suggestions so far. It's given me a lot more to think about, even if I now feel I understand a lot less than I did yesterday. Attached are a couple more shots of the board, front and back.
The IC circled in red is (I think) the PWM controller for the current the PSU outputs. It is a UC3843BN, leading to a K2717 Toshiba N-type Mosfet specced at 600V and 5A and then to the large transformer. This initially had nothing on the output pin, so I swapped it out and now I can output power, although...Leave a comment:
-
Re: IDing transient voltage supressor
It should test like a regular diode. These sit backwards in the circuit and most of the time do nothing, bar absorbing any minor voltage spikes. But if a too high voltage comes through they commit suicide and die as a short circuit. Current then passes straight through that rather than the more sensitive circuitry it is preventing. It's a bit like a reverse fuse in that it conducts when it has blown, so if it's showing open circuit then it needs replacing.
Well actually, if you are feeling brave and you trust your power supply...Leave a comment:
-
Manson 80W Constant Power Switching Mode Power Supply
I'm trying to get the above power supply working. On the outside it's a neat little thing that you can dial up any voltage from 0-36 V and limit the current via two rotary encoders connected to two LED displays, and independently switch the output on and off (link to [URL="http://www.manson.com.hk/en/dcpowersupplies_detail.php?m=2&id=32"]manufacturer's site[/URL] and also sold under various brand names). Someone's done an independent stripdown [URL="http://naklojik.blogspot.com/2011/09/maplin-n27gg-80w-switching-bench-supply.html"]here[/URL] of the version shown by Maplin... -
Re: Recommend me a MultiMeter
If you've never used a multimeter then I'd recommend getting pretty much the cheapest that you can, either say [URL=http://www.maplin.co.uk/Module.aspx?ModuleNo=37279]this one[/URL] or [URL=http://www.maplin.co.uk/Module.aspx?ModuleNo=44679]this one[/URL]. It'll do 95% of what you want, and after a few months you should be pretty aware of what its limitations are, what extra features you want when you upgrade to a better model, and what is just unwanted eye candy. At that price chances are that it will cost you more in petrol and parking to get to the...Leave a comment:
-
Re: Chimei DAC-19M009 Power Supply problems
The bridge rectifier was blown, so I stuck in one taken from an old PC PSU, changed the fuse again, and gave it a try and it all seems to work OK. Now the gamble is to stick with it as is and assume an outside surge blew the rectifier, or to keep exploring, and risk damaging the board with my pretty basic soldering/desoldering techniques. Thanks for helping me get to a working monitor.Leave a comment:
-
Re: Chimei DAC-19M009 Power Supply problems
OK, it's not just a power surge that popped the fuse; I stuck another in there and that went the moment I plugged it in. Does that suggest that the faulty component is likely to be close-by? I'm not too sure where to look next. I had hoped that the dud fuse suggested that those FETs were really OK. Would they cause the main fuse to blow? Thanks for the help so far. I would never have realised that the little black box squeezed in under the power cable was a fuse. Is it normal to make them so inaccessible?Leave a comment:
-
Re: Chimei DAC-19M009 Power Supply problems
The big cap gives me nothing at all, which suggests that something on the mains side has gone. Looking closer I see that underneath the wire earthing the board to the mains socket there is a fuse marked T3.15A 250V CQ and under that MST JET. A fuse which has blown. Bearing in mind the clean state of the rest of the board I'm tempted to find a replacement and see what happens. Now I just have to get at the awkward little fellow....Leave a comment:
-
Re: Chimei DAC-19M009 Power Supply problems
OK, Assuming that the dot on the top of the FET marks pin1, and that they then run 1,2,3,4 up to the top then 5,6,7,8 down the other side, and according to the datasheet the pins are (from 1 to 8) S2, G2, S1, G1, D2, D2, D1, D1, then I get the following readings, pretty much identical on both FETs, according to which way round I have the DMM leads (Red/Black)
S1 Red to G1 805
S1 Black to G1 787
S1 Black to D1 663 (both pins)
S2 Red to G2 330
S2 Red to D2 614 (both...Leave a comment:
-
Re: Chimei DAC-19M009 Power Supply problems
D'oh! I was making such a hash of trying to upload a photo that I missed that bit out. It's completely dead, no sign of life at all, not even a blinking LED.Leave a comment:
No activity results to display
Leave a comment: