Reply
Member
b0w_bender
Posts: 3

Re: red light flashing on a 42HL196.

thanks I would prefer to be alive and without a TV then dead :-)

I'll look for a tech. I'm a highly mechanically inclided person but when it comes to electronics i'm an ignoramous so probably best If butten it back up and take it to the recycling place.  We got 6 years out of it and we'll look at a different brand for the next one.

Member
chaosmountain
Posts: 1

Re: red light flashing on a 42HL196.

[ Edited ]

One thing I noticed that no one touched on, is the heat sink ?

 

It is kind of a pain to have to desolder it along with the STRW6765 because that thing is bonded big time to the heat sink by the thermal compound.

I would like to see a photo of what IKnowTech did with his custom heat sink.

 

I bought one of these off of craigs list for $35.00, ordered the STRW6765 off E-bay for $8.00 shipped, spent an hour taking out the board, replacing the part and putting it back in.

 

It fired right up and ran great!!

My 28 year old daughter is a happy camper to say the least!!

It is for her room as she has been watching TV through her PC monitor which is only 17"!!

LOL!!

 

Here is a photo of the part for anyone who wants to know exatly where it is and what it look like.

 

 

 

 

Occasional Contributor
IKnowTech
Posts: 20

Re: red light flashing on a 42HL196.

I still occasionally check this forum even though the TV has been working fine since the repair.

 

As I mentioned, I really don't want to haul the TV down and open it up just to take pictures, but I can briefly describe what I did with the heatsink.  I was stumped at first as I tried to find an extrusion that was about the same profile but longer, so adding a couple small chunks turned out to be the best option.  Since I had the heatsink removed, it was much easier to make modifications before re-installing it.  Here's what I did:

 

The non-finned center flat area on the opposite side of the STRW6765 regulator chip is just over 0.5" wide.   I had on-hand a few small heatsinks for bridge rectifiers; base dimensions 1'' by 1'' with six 1.75" tall fins and a hole in the center of the base.  I carefully sawed one in half so I had two pieces 0.5" by 1" with three fins each.    In each piece, I drilled a #4 size hole about an inch deep in the center of the base, opposite the finned side. On the removed heatsink, I marked two drill spots 1-1/2 inch apart symmetrically centered horizontally on the existing regulator mount hole and centered vertically in the flat area, and drilled two #6 holes (cleaning off any burrs). The two heatsink pieces were then coated with thermal grease on the bases and attached to the non-finned flat area opposite the regulator chip side.  #4 self tapping 1" screws through the chip side holes of the heatsink fasten the two pieces; before tightening them for good, line them up so the fins are in line and centered in the non-finned channel. 

 

The added heatsink extends past the edge of the PCB but they are clear of any obstructions, and the fins run in the vertical plane in parallel with the extrusion of the heatsink.  I estimate that the theta of the heatsink is lowered by probably 2-3C/Watt, which amounts to between 20-30C reduction in die temperature if the chip is dissipating between 10-15Watts.  This can make a huge difference in reliability for a device that runs as hot as this one seems to in this design. 

Member
harlock
Posts: 6

Re: red light flashing on a 42HL196.

do you have a record of the cap values for the ones you replaced? it would be nice to order the caps without having to open up the tv.

thanks


IKnowTech wrote:

To verify this theory, I soldered around 50uF of ceramic capacitors on three rails; 24V, 12V, and 20V.  These were soldered on the backside of the power board in parallel with capacitors C872, C873, C888, C889, C890, C895, and C896.  When plugged in, the 12V remained present after the second relay click, and the TV turns on and works normally.  It appears the problem is bad capacitors and I'll be replacing those shortly.  

 

Occasional Contributor
IKnowTech
Posts: 20

Re: red light flashing on a 42HL196.

Yeah, just happened to see this.  I bought 6 pieces of 1200uF 35V (Digikey P12406-ND) for the 1000uF cans, and 2 pieces of 680uF 35V (Digikey 493-6930-ND) for C895 and C896.  I replaced the rest of the electrolytic caps on this board as well (except for that big 450V can which is quite costly) but the 8 main ones I mentioned above are critical as they are subject to the highest ripple current stress. 

 

Keep in mind that all this may still not fix your set;  you have to go through a methodical process of measuring and ruling out potential failures, which you'll absolutely need the service manual for (Freely available on the web). 

 

And, I'll repeat again, perform such service under strict high-voltage safety protocols.  Don't even think of trying this if you've never worked with 400Volts DC before; It is an absolutely unforgiving voltage level.

 

 

Member
spark_d
Posts: 1

Re: red light flashing on a 42HL196.

Exact same problem here - It's nice to see I'm not the only one who spent thousands on a tv with a shelf life of a few years - thank you for standing behind your broke product Toshiba - I won't make the mistake of buying another one ever again and I'll make sure that my friends and family won't either.

Member
harlock
Posts: 6

Re: red light flashing on a 42HL196.

[ Edited ]

awesome, i have a few local stores i can buy from so today i will check the only one that is open on a saturday,

i picked the tv up from someone who was moving knowing it had the problem (they were going to take it to the recycler). it did work the first couple times i had it plugged in then the 3rd time i plugged it in the heard the relays click  3 times. so i'll do the caps and if i need to, the voltage regulator.

thanks

 


IKnowTech wrote:

Yeah, just happened to see this.  I bought 6 pieces of 1200uF 35V (Digikey P12406-ND) for the 1000uF cans, and 2 pieces of 680uF 35V (Digikey 493-6930-ND) for C895 and C896. 

 


 

Member
harlock
Posts: 6

Re: red light flashing on a 42HL196.

 

the 46" regza i bought in jan 2009 still going strong. if you are going to boycott every manufacturer who has had capacitor issues that is going to be a very very long list.


spark_d wrote:

Exact same problem here - It's nice to see I'm not the only one who spent thousands on a tv with a shelf life of a few years - thank you for standing behind your broke product Toshiba - I won't make the mistake of buying another one ever again and I'll make sure that my friends and family won't either.




Occasional Contributor
IKnowTech
Posts: 20

Re: red light flashing on a 42HL196.

You've got that right.  The sad truth is that most set makers (and laptops and mobile devices), especially those who's primary business is not home entertainment electronics, have their TVs built by ODM suppliers whose names are unknown with respect to the brands they build for (think Apple and Foxconn).  The reason the support is so poor is because the brand name company has little control over the part procurement practises of an ODM supplier once that ODM makes it to the brand companies Qualified Vendor List. 

 

I've repaired 6 TVs and 1 monitor and I can say that all but 1had capacitor issues, and there were a couple big name brands in that group (names starting with "S").  Two sets had outright design errors as well as capacitor problems (I count my Regza as one of those since I would never have designed a power device to run so hot).  So far my repaired TV has been workiing fine.  I have had one instance where it's internal computer got "wedged" and it would not respond to button presses, requiring holding the power button on the frame depressed for 5 seconds to invoke hard-reset.

 

 

Member
CraigR
Posts: 6

Re: red light flashing on a 42HL196.

Ok this one has got me ticked off! Toshiba 42HL196 has 3 lights flash over and over. I had read this is a common problem for this set. I ordered a repair kit online that came with Q880, D892,D887,D883,R883,R884 put it all in and same thing no help. I read here on the forum to put in 2 others Q820 and Q860 I first put in Q860 and tested No difference. Then put in Q820 and also no help but now I hear the relay clicking over and over again. Not sure where to go now as everything I have read on this set replacing those should have worked.

Member
Arffgirlazo
Posts: 1

Re: red light flashing on a 42HL196.

Ok I did some research and everyone on the first two pages did it all wrong or spent money when they didn't have to, here's a easy answer that works and it's fixed the two flat screen Toshiba's we have here at the firehouse. I Included two pictures so you can see how to fix it. You need to take the 37+ screws off the back cover of the tv, then on the bottom center are pictured here you have to take the white clip component out, and that's it, just pull it out and screw the cover back on and it's as good as new, I can't remember why they said it was causing the malfunction but if your power button light is flashing red this will fix it. Oh and I just want to mention I'm a girl and I figured this out, not hard to do.
Member
CraigR
Posts: 6

Re: red light flashing on a 42HL196.

[ Edited ]

Arffgirlazo these pics are not even from this TV model so NO this would not fix it.

Member
CraigR
Posts: 6

Re: red light flashing on a 42HL196.

Anybody???

Member
harlock
Posts: 6

Re: red light flashing on a 42HL196.

@CraigR how about replacing the caps mentioned in this thread.

Member
CraigR
Posts: 6

Re: red light flashing on a 42HL196.

All the caps were removed and checked good with my ESR meter.

Occasional Contributor
IKnowTech
Posts: 20

Re: red light flashing on a 42HL196.

Just came across this. 

 

The commercially available repair kit is inadequate IMHO since it only replaces all the main power path ICs.  Although it's a good tactic for dealing with one device failing and wiping out a chain of devices in its wake, it doesn't address the potential root cause, which may be caps gone bad.  My attitude is, if I go to the expense and trouble of replacing all the semis, replacing the caps whether they are faulty or not is less than half the cost of the semis and protects the investment  if it was a faulty cap that took them out in the first place. Pretty cheap insurance, don't you agree?  The better rebuilder shops will do this as a matter of course.

 

You may still have a cap problem; unless your ESR meter tests the caps with appreciable ripple current, one or more may still be at fault.  You need to examine what is going on when the relays click using a scope, and you'll need the service manual (freely available on the web with some googling).  Just power the set up long enough to see what's happening on the rails to limit the amount of power-ON time since an undiagnosed fault may take out the chain of semi's you just replaced. 

 

When you plug the AC in, the main 12V is supposed to come up immediately and stay on.  If it's there, and the LED continues flashing indefinitely, that means the main CPU on the Seine board is not booting.  The LED is flashed by an independent controller that is powered from a separate standby power supply.  Once the main CPU boots up, it signals the controller to stop the flashing.  That's what happens when the LED flashes a few times after AC is plugged in, then stops.

 

If the 12V comes up briefly then goes out, the problem is with the PSU.  This is what I first encountered with my set. My suspicion turned immediately to the big filter caps on the secondary side.  When I soldered ceramic caps across them (ceramics have really good ESR), the set started working, but, as it happened, Q880 had already been crippled by bad caps and faulty thermal design, and finally died a couple weeks later.   After replacing it with improved heatsinking, and all the electrolytic caps replaced (except the big expensive 450V can), the set has been working fine now for over a year, having survived several AC outages.

 

I assume I don't need to remind you that the heatsinks on the PSU board are all line-voltage-hot, so HV safety should be at the forefront.  If you are scoping anything on the PSU board, you MUST power the set from an isolation transformer, no exceptions!

 

 

Member
CraigR
Posts: 6

Re: red light flashing on a 42HL196.

[ Edited ]

Replaced all electrolitic caps and have no scope. still nothing. light on the front flashes 3 times then twice then maybe one more and just goes out and relay just keeps clicking. Also tried another Seine board.

Occasional Contributor
IKnowTech
Posts: 20

Re: red light flashing on a 42HL196.

CraigR, sorry but you can't get much further than this without a scope.  When Q880 died in my set, I needed the scope to determine that it was Q880 and nothing else.  Make sure you plug in the fan cable on the Seine board; I didn't check for this model but in some TVs, if the fan RPMs can't be detected (fan jammed, failed, or disconnected), the set won't power up and will flash an error code.

Since you went to the trouble of swapping the Seine board (I won't ask how you happened to have one lying around), I assume you had ruled out the PSU, that is, the 12V is present when the set is plugged in? If that's not the case, the PSU board is still the most likely culprit.  The good news; it's much more repairable than the Seine as long as the main transformer isn't shot, plus the schematic and datasheets for the main semis can be found on the web. The bad news;  you need to understand off-line quasi-resonant power converters and active PFC circuits to properly diagnose the problem, and, yes, you'll need a scope.

This is as far as I can help without the TV in front of me with proper test gear.  Best of luck getting it going.

Member
CraigR
Posts: 6

Re: red light flashing on a 42HL196.

I even ordered another new Q880 just in case the first one went bad and same problem. I guess find a good board.

Member
harlock
Posts: 6

Re: red light flashing on a 42HL196.

[ Edited ]

 

As for the tv i'm fixing it would occasionally work, I finally got the caps ordered and just put them in, but still it doesn;t consitently work, fired up the first time right away but then i tried unplugging and replugging only to get 2 relay clicks instead of one. so i'm going to try the voltage regulator now.