Toshiba TV intermittent Remote Reception

[cato]

Dads 32A61 responds to any of 3 remote controls only intermittently. Has anyone seen a Remote receiver section quit working before? So far, he has ruled out IR saturation (from sun light or such) and dust accumulation (external).<p>Any thoughts?

[Edd]

Hmmm the ‘32’ of 32A61 equates/= with…… hernia…but with 3 xmitters you have narrowed down as an in set condition. Now along with the “dust accumulation” have you also ruled out the situation of a permeating/stubborn film from being a chain smoker on the cabinets external plastic filter medium in front of the IR sensor. It typically takes “409” to get that stubborn film off .The aforementioned, naturally being relevant to decreased sensitivity at a distance, and not an inoperative condition. After that possible consideration, you would have to get internal cabinet access to the frontally positioned IR detector module and meter its three terminals. One terminal will be a 5VDC power supply source, another a power ground, and the last will be the all important conditioned serial pulse train output decoded by the units electronics.
The first thing to hope for is a marginal/floating solder fractured connection to one of the three terminals that has developed with time. That out of the way, its then a piece of cake if you are monitoring with a scope, but within the realm of tracing by even using the AC function of a DVM, etc. Probe at the output with your DVM in a fixed range and cascade down until you recognize the response to a repetitive transmitted function from the remote hand unit held near the detectors front. Starting at the output of the sensor unit, the pulse train info will route its way towards one pin of a large multiprocessor. Since you will typically find yourself without a schematic reference, its certainly not out of the realm of visually tracing the foil path back towards the U/P as there typically will only be a series resistor enroute. Possibly a via or two in the route also…if it’s a dense board in some areas.
Probably at this extent of troubleshooting you will have pinpointed a loss or no presence of signal. If there was a possibility of the sensor being at fault, you will need to have the set operational and the routing of a short test wire from the sensor output terminal and spiraled around the meter probe so that it might be left adjunct to the set and then flipped on to see if there was an output when the set was in its inoperative remote condition. <p>Zujing for your evaluaton/research and feedback.<p>73's de Edd
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[jollyrgr]

Edd provides some very useful information. If your dad (or other person living with him) smokes, check for smoke film over the sensor. Also check for cold solder joints on the IR sensor. You can scavenge a replacement IR receiver from a junked VCR or other device. Or save yourself the headache and go to the nearest Radio Shack. You can get a replacement there for under four dollars. Go here:
http://www.radioshack.com/product.asp?c ... id=276-640<p>Like Edd says these are easy to figure out. Don't assume that the pin out will be the same! Finding the +5 Volt connection should be easy using a volt meter. If you recognize how to follow traces on the main board, so will the ground connection easily as well.

[cato]

Thanks Gents!<p> Dad smokes like a chimney....and I don't mean the whimpy Pope election kind either. <p> Edd - other than casting doubts on my favorite web dictionary:<p>The word you've entered isn't in the dictionary. Click on a spelling suggestion below or try again using the search box to the right.<p>Suggestions for zujing:
1. sieging
2. zigging
3. schussing
4. sagging
5. Zigong
6. soggier
7. zoogenic
8. Saginaw
9. zagging
10. Sugiyama<p>, your post was great and above and beyond, as per usual.<p>73<p>[ April 25, 2005: Message edited by: cato ]</p>

[Edd]

Ohhh-tay:
Here is some more set specific info , at least as close as a 32A60 version.
The chassis proper is laid out as a long rectangle F to B. When viewing from the rear, your point of interest will be the very front of the chassis , just to the right , off center , where there will be the IR sensor and its on board electronics and is mounted/centered just between the video and menu tact switches. Its left terminal is ground, the center is the demod pulse train sig output and the right terminal is +5Vdc power.
The sensor output routes to a 1K series resistor( RA35) and then on to pin 35 0f the U/P QA01 that sits about 2 in back from the chassis front/center. Its pin 42 is the end pin closest to the sensor.
That prior info is there if you need it later, but I think that your problem is going to be in the ancillary circuitry of a five terminal regulator. It is in a TO-220 case configuration and is located in the extreme top left corner and has been assigned a transistor symbol designator of Q840…vice a typical ….IC840. It is the standby power source for the set. Its 5 pins are staggered and number left to right as 1-5. You will need to trace the foil path from pin 5 until it ties into a radial electrolytic cap that is designated as C842 [100ufd @ 16Vdc].. How about replacing that cap and then your giving the set a shakedown evaluation period on reliability.
Specifically,to the extent of eliminating that sets inoperative tendency of not working only on some Thursdays when the wind is out of the southwest and the temperature is above 72 degrees and a blue Ford pickup comes rumbling down the street.<p>Sorry ‘bout that, seems I must have thrown you on that alliteration of a prosign. Maybe this structuring would have been better:<p>ZUJ’ing for you.
http://www.zerobeat.net/qrp/zsiglist.html <p>
73's de Edd
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[cato]

Ah, QSL QUC 576 RST 599 73 SK

[Edd]

[cato]

- --- - - - ..--.. .-- .- ... - .... .- - .- - -.-- .--. --- ..--.. --- .-. .-- .- ... .. - .. . .- -. - - --- -.. . .- ... .- ... - ..- - - . .-. ..--.. ... -.-<p>[ April 28, 2005: Message edited by: cato ]<p>[ April 28, 2005: Message edited by: cato ]</p>

[Edd]

Noitwasnotastutterbutwithyourtightfistandbyvirtueofitscloseintercharacterandwordspacinginadditiontocodeproficiencyitalsorequiredcryptographyandsome
statisticalpermutationallogictodecodeit.
Sooo…have you had time to get into dear ‘ole dad’s Tee Wee or is it to be relegated as some week end task?<p>73's de Edd
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<p>[ April 29, 2005: Message edited by: Edd Whatley ]</p>

[cato]

I'm afraid Dear ole Dad is on his own as he is on the East Coast and I am on the North Coast, but I have passed along your words of wisdom, for which he is grateful. He reports vacuuming out the innards with accidental (incidental?) tappage upon a capacitor you identified. However, he reports the procedure had little if any effect. <p>While he and my brother (who is local to him) hold intermediate level amateur radio licenses neither is acutally competent to dig very deep into this problem (dang no code licenses) So I suspect a service call will eventually be made. In the mean time he has ordered the schematics. Maybe I can point him at which parts to wiggle if he scans them and sends me copies.<p>Sorry about the tight fist. I couldn't figure out how to create the luxurious gaps you created. I acutally typed spaces, but this board seems to assume that since the characters I typed were periods and hyphens I didn't really want the spaces.

[Edd]

While he and my brother (who is local to him) hold intermediate level amateur radio licenses neither is actually competent to dig very deep into this problem (dang no code licenses) So I suspect a service call will eventually be made.
In the mean time he has ordered the schematics. <p>Hope he hasn’t taken action yet, as I have availability for free to you, but I believe that enough info has transpired on:
• Step one, localizing/pinpointing of the IR block and its three terminals, they just need a reflow soldering action done upon them.
• Step two, the only other questionable task was the physical locating (no photos on the schema so that’s why I mentioned foil path tracing
or silk screen marking on the chassis at the capacitors side) of the specified 100 ufd electrolytic and it being replaced there was no suspicion of floating ring joints on the original capacitor.
So you need to empower the most adept solderererer of the two to suck and wick the caps lead terminals and replace the unit.<p>Maybe I can point him at which parts to wiggle if he scans them and sends me copies.<p>I think …a…la …. der Jolly Rogerewski….…no wiggling was necessary in the performance of this repair….much in the manner of all the universe’s physics elements that his repetitive signature refers to.<p>How he do ‘dat ?
a cell…a cell….I isolated the code elements within a cell.<p>
73's de Edd
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<p>[ April 30, 2005: Message edited by: Edd Whatley ]</p>

[cato]

Thanks for the offer. However, the deed is done. He has fixated on a 47uf 5v bypass cap for some reason. <p>I have advised him to look for solder and trace continuity issues before futzing with cap replacement. No reply as of yet.

[cato]

Thought I owed you guys a follow up.<p>Service man was called. 3 minute in home diagnosis "its the microprocessor".<p>Set was taken to the shop for repair. <p>Ultimate repair:<p>Replace microprocessor AND IR receiver unit.<p>....sigh.... we tried [damn no code license]<p>Thanks again for all your help, consideration, input, efforts and time.<p>seventy fleas

[Edd]

Heeeey Kato how's with the Green Hornet or O.J. ?
I can certainly see a floating wire lead in a solder land or a disrupted foil path, the two bypass electrolytics that I mentioned, or the small IR detector /preamp/module unit proper.
But, just between you, me and a doorknob, I’ll just “feel” that the control u/p was not a “REQUIRED” part… since he was always able to enact control thru the front of sets control pushbuttons.<p>73's de Edd
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[cato]

I agree. Thats what I told him pre-servicecall. I guess they felt charging him what ever they did for cleaning up a solder connection would be wrong....so they told him they replaced some components.<p>shrug...what ya gonna do<p>http://www.cato.org/<p>Intelligent Design: Clearly the human body was designed by a civil engineer. Who else would locate a great recreational facility so close to a waste disposal facility?<p>[ June 02, 2005: Message edited by: cato ]</p>