Re: Toshiba 19W330DB (Vestel 17MB24H-2 190407) freeview/DTV not working
Hi, which one? I think it might be a trick of the light. Also yes I've been told that it works fine with an external DVD player.
Is that smaller board with the card slot at the top responsible for DTV decoding or is that likely done on the main board? This TV came from an era when built in freeview/DTV was still being rolled out and many were using external set top boxes....
John843883
Senior Member
Last Activity: 01-06-2023, 05:46 AM
Joined: 11-16-2012
Location: nowhereshire
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Toshiba 19W330DB (Vestel 17MB24H-2 190407) freeview/DTV not working
Hi, got a friends older (2007-08) bedroom LCD TV here and the freeview/DTV has stopped working and just displays a black screen with occasional flashes of green or reddish-pink near the top of the display. Apparently it just went without any prior warning signs.
Other inputs appear to work fine and when switched to analogue (this is an old TV) I get the regular snow pattern so I don't think it's the screen itself. Can't test a true analogue TV signal since analogue TV was switched off years ago in the UK.
I've taken the back off and reseated every connector and prodded...Last edited by John843883; 01-04-2023, 06:06 PM. -
Re: Can a failed input smoothing capacitor destroy the switching IC?
Thanks. Well the DVD player belongs to a relative of mine who only lives a few minutes away so if it fails again then it isn't much trouble to get it back over here. I don't think they use it much anyway what with everything coming down the internet these days....Leave a comment:
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Re: Can a failed input smoothing capacitor destroy the switching IC?
Yes I am well aware of that, but when its first plugged in the 400v 22uF capacitor is empty and needs to charge up basically representing a brief short to the mains and with no inrush liming on the PSU wouldn't a larger one risk blowing the little 1 amp fuse or diode bridge?
Anyway its currently back working again using junked parts for now.Leave a comment:
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Re: Can a failed input smoothing capacitor destroy the switching IC?
Hi, there doesn't appear to be any tolerance markings on the original orange ceramic capacitor.
Also I'm not sure if the ones I found in my parts box are actually safety caps or not but they're blue and have the capacitance and voltage ratings on them, some are 1kv and others are 2kv, they don't have all that tiny text you often see with safety class capacitors however.
They look like this.
[ATTACH]231576[/ATTACH]
Regarding the input capacitor size, I wonder if its...Last edited by John843883; 03-02-2021, 07:40 AM.Leave a comment:
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Re: Can a failed input smoothing capacitor destroy the switching IC?
Thanks, the ceramic capacitor is currently an orange disk ceramic type, would blue safety class capacitors be acceptable there?
And yes I'll check that standby cap too....Last edited by John843883; 03-01-2021, 12:40 PM.Leave a comment:
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Re: Can a failed input smoothing capacitor destroy the switching IC?
Another update: I've found that the 10nF orange ceramic capacitor for the switching transistors RCD snubber reads as 8.8nF out of circuit rather than the full 10nF, is this likely to be a problem? Its value seems to drop by a further 1nF from just my body heat when I've handled it.
Also I've just been told that infact the DVD player has been left in standby for all those 4 years of disuse so plenty of time for the capacitor to fail and the machine to blow its fuse noticed.Last edited by John843883; 03-01-2021, 09:33 AM.Leave a comment:
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Re: Can a failed input smoothing capacitor destroy the switching IC?
Thanks. So just how does a bad input smoothing capacitor destroy the IC? Also its the big 400v mains input smoothing capacitor and not the standby capacitor for the IC which has gone bad.
Here's the PSU, on the back of the DVD player it reads "power dissipation 20w".
[ATTACH]231489[/ATTACH]
[ATTACH]231490[/ATTACH]Re: Can a failed input smoothing capacitor destroy the switching IC?
Thanks. So just how does a bad input smoothing...Last edited by John843883; 03-01-2021, 04:53 AM.Leave a comment:
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Can a failed input smoothing capacitor destroy the switching IC?
Hi,
I'm looking at a DVD player (Tevion QS808) which has not been used in about 4 years, on the power supply its 1 amp glass PCB fuse is blown and the VIPer22A switching IC is shorted 60 ohm between drain and source with a hole blown out the side on pin 2 (source).
The main 400v 22uF "Acon" input filter capacitor is swollen and measures just 271pF, could this have caused the switcher IC to have blown? I can't find any other obvious faults on the board with a meter.
Thanks.Last edited by John843883; 03-01-2021, 03:15 AM. -
Re: Toshiba backlight flashing problem
Update: It's model number is 19w330db and shaking it physically doesn't seem to change anything.Leave a comment:
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Toshiba 19w330db backlight flashing problem
A friend sent me a video of a fault his TV developed. Haven't physically looked at it yet but I'm assuming backlight CCFL going out, cracked solder joint/loose grounding screw or capacitors? Almost looks like the backlight is flashing white every so often.
Here is the video clip he sent me: [URL="https://imgur.com/a/OtKcEPQ"]https://imgur.com/a/OtKcEPQ[/URL]
Anyone seen this sort of thing before? TV is a small Toshiba LCD probably from around the mid 2000's when LCD's like this were becoming affordable.
Any hints/experiences with this sort... -
Re: Dell Inspiron 1545 CCFL to LED screen swap
Went pink and went out....Leave a comment:
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Re: Dell Inspiron 1545 CCFL to LED screen swap
Thanks but that looks too complicated for me.
Thanks but unfortunately I don't have any spares here, I'm not a repair shop.
Definitely nobody else here who's successfully made the swap?...Leave a comment:
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Re: Dell Inspiron 1545 CCFL to LED screen swap
Oh thanks, have you made this swap yourself? It's just I'm reading all sorts online and some people say yes whilst others say no including ebay sellers.
Don't want to buy one and find out my motherboard revision doesn't have the hardware to drive the LEDs or the bezel and LCD supports differ. But on the other hand they probably don't make them anymore and I'm guessing most of the CCFL versions on sale are pulled from old machines and CCFL's wear out over time....Leave a comment:
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Dell Inspiron 1545 CCFL to LED screen swap
Hi, I'm going to replace a failed CCFL screen in a friends older dell inspiron 1545 laptop but I've noticed there was also an LED screen option for this model. Can I simply swap them over and buy the LED cable or are there things such as motherboard differences etc?
Thanks. -
Are Rubycon YXJ for SMPS or not?
Are Rubycon YXJ ok for the secondary side of a flyback converter? The datasheet shows impedance figures for 100khz but doesn't actually state low impedance as a feature.
What drew me to these were the long endurance life as they will be used in an enclosed SMPS that runs hot 24/7 as part of the secondary sides LC ripple filter. Another reason I didn't go for one of the really low ESR series that you can get these days is this seems to better match the ESR of the original capacitor its replacing.
So yeah are Rubycon YXJ ok for flyback secondary side filter use? I'll be...Last edited by John843883; 11-08-2019, 03:44 PM. -
Sky HD box DRX780
Anyone repaired the PSU in one of these and if so is there anything I should be checking before powering it back up again?
I've replaced all of the failed capacitors including the Rubycon ZLH's and I came across some odd schottky diodes with very high reverse leakage current Sanken "RA13" which had me stumped for a bit.
Nearly all the capacitors on the PSU tested bad but not all had visible signs, one day it just failed to even enter standby. Is replacing the capacitors all there is to getting these back up and running again or are there other things that... -
Choosing a Ceramic Multilayer Capacitor
Hi, I need to replace a Ceramic Multilayer Capacitor out of a car battery charger and was wondering which one to select? I've been reading up on those types of capacitors and have found out that they can change depending on applied voltage.
Here's the deal, I can't find anything related to this in the datasheets for the shortlist I have compiled. Its almost like the manufacturers would rather you didn't know this information.
The capacitor on the board had failed semi-short (150 ohm) so I can only guess the specs, but it looks to be about 1uF and is on the input of... -
Re: Makita 440 Cap types?
At-least you've now got spares for future repairs, put them in storage and hope something else fails!Leave a comment:
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Capacitor sleeve shrinkage?
As the title suggests I've come across a capacitor where the sleeve appears to have shrunk and retreated up the side of the capacitor body.
Anyone know what the causes of this sort of thing would be? The capacitor is a Rubycon BXA 400V 2.2uF, capacitance measures fine but ESR is a bit high at 16 ohms. No signs of bulging or leaking.
I'm not trying to repair anything but I'm just curious as to what causes the sleeve to pull back like this? It came out of an old 8w cfl bulb and this capacitor caught my eye, so maybe its just heat related? I couldn't find the missing bit...Last edited by John843883; 05-16-2018, 10:33 AM.
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