Hanspree HF235DPB turns on for 0.3 seconds...

[John Hancock]

...and goes off. It's a fully bright screen for that portion of a second. I can turn it off and on, off and on and the picture will pop-up for that portion of a second every time. This was a sudden thing, no fading picture or flickering or any sort of warning.

I did the flashlight test and can see the picture is there in the blackness.

The green power light stays on.

I'm not sure which model number it is from the tag on the back, both pull it up:
HF235DPB
HSG1108
It's only 2yrs old.

I have an even more no-name (V7 22") slickdeals monitor that's been running strong since 2008/9.

I already opened up the case (no screws!?) with an old metal spatula. Then I had to undo some tiny plastic connectors and screws to unhook the video chip board so I could actually separate the two case pieces as a video ribbon cable of some sort was holding it together. I also had to unclip the power wires from the power board to the screen. No caps appear to be leaking or misshapen.

I've attached a few pics.

It uses the following caps:
CapXon 470uF 25v (x4)
CapXon 680uF 25v (x2)
Su'scon 1000uF 25v (x2)
Su'scon 470uF 25v (x1)
Su'scon 470uF 16v (x1, it's on an upshooting segment of circuit board)

If you can't tell, I'm new to this. I have built my last three PC's and soldered a few times like a decade ago lol.

Any help is appreciated!

[u271D]

Re: Hanspree HF235DPB turns on for 0.3 seconds...

Have you check the ESR of the caps?
I worked on a Philips lcd that did the same thing, opened it up saw some bad caps and then checked them all. Found a cap that looked fine but was 10x out of spec.

[John Hancock]

Re: Hanspree HF235DPB turns on for 0.3 seconds...

Have you check the ESR of the caps?

Nope.

And googling ESR, the meter looks cost prohibitive for my situation.

I do have an old multimeter laying around somewhere...

[u271D]

Re: Hanspree HF235DPB turns on for 0.3 seconds...

DMM won't do an ESR check; if your going to start repairing stuff your going to need a DMM that's accurate, and for caps a ESR meter. Check out this one, its the ESR meter I started out with and still use sometimes. You can get it as a kit, solder it your self to save some money.
http://shop.anatekcorp.com/index.php...nt%20Analyzers

[John Hancock]

Re: Hanspree HF235DPB turns on for 0.3 seconds...

DMM won't do an ESR check; if your going to start repairing stuff your going to need a DMM that's accurate, and for caps a ESR meter. Check out this one, its the ESR meter I started out with and still use sometimes. You can get it as a kit, solder it your self to save some money.
http://shop.anatekcorp.com/index.php...nt%20Analyzers

Thanks for the link, but I guess what I'm trying to say is that I don't want to spend $100 on a specialty tool (attempting to fix a low-end monitor) when I can buy a brand new Asus 23.6" LED IPS model on Amazon for $129 after a $20 rebate. I just moved into my first home last year and I've spent a lot of money on tools and the likes for DIY upgrades (lighting, electrical, yard, saws, etc).

Do you know if Radio Shack carries an ESR meter for customer usage? Or would something like that have disappeared since they're so commercial/retail now? I guess I can call them tomorrow. If not, I guess I can just order some caps/solder/iron and hope for the best

[1supertech]

Re: Hanspree HF235DPB turns on for 0.3 seconds...

Radio Shack won't have the right caps go to Digikey http://www.digikey.com/?WT.srch=1&WT...Q15-1t1-VQ16-c
us Panasonic caps series fm, fc,fr

[u271D]

Re: Hanspree HF235DPB turns on for 0.3 seconds...

I don't know if radio shack will lend a tool. If they have a LCR meter some of them do ESR measurements; and like the other guy said they wont have the replacement caps you need. They don't have low esr caps as far as I know.

You can just replace all the CapXon caps, that would be a good start. But with out the right tools your just taking a shoot in the dark.

[rboyer]

Re: Hanspree HF235DPB turns on for 0.3 seconds...

Not saying that it's definitely your problem but that model is actually known for blowing ccfl lamps. I priced lamps for some of these before and ended up throwing them out when I realized that it would cost me like $50 in lamps to fix a used monitor that costs $100 new. I know they used an InnoLux panel and trying to find complete ccfl assemblies for it to just drop in was impossible at the time. Honestly if I fix a 32 inch tv I usually set a limit of $40. If I don't forsee myself repairing it within that limit then it goes into storage until I happen to run across another broken model which has the parts I need. You need to set a point at which your willing to take a gamble. It's worth re-capping an inverter but anything after that can possibly drive you into a hole where you spend more time into something than it's even worth.