panasonic travel tv 1 inch screen

[timmy]

Originally Posted by jhalphen

Hi Timmy,

I pulled from the Web the spec sheet on the AN5760, the Vertical processor & output chip of the TR-1010P. It's clipped to this message.



Alas, there is a standard fault with a given model of TV. There are a fair amount of elecrolytic caps - i counted 7 in the Panasonic application note and as you said you had changed all the electrolytics, i would carefully go over each and check that one was not mounted with the + & - terminals reversed. In tight circuitry or when tired, even trained technicians sometimes make mistakes.

Of course a new Cap mais sometimes be bad but if yours are from a reputable brand, Panasonic, Nichicon,... this very seldom happens.

If you like repairing electronics, an ESR capacitor checker would be a valuable tool to have. ESR stands for Effective Series Resistance. The great advantage of this type of checker is that you can check electrolytic Caps in-circuit without desoldering them - a phenomenal time-saver when troubleshooting.

With an ESR meter you can check electrolytics from 1µF to the sky.
Under 1µ & non-electrolytic caps, the meter is useless.

to buy one, search a reputable test gear dealer such as this one:
http://www.tequipment.net/index.html

Other members may suggest a brand/model they like.

Best Regards

jhalphen
Paris/France

well that is one thing i did do and check the polarity, the neg of the caps is the half circle on the board so i ruled that out thank i didnt make a mistake. its just that what i did and checked seems not to be whats wrong and that im overlooking what it really is. but yes its really tight in there to work on. i did change both ics vert and horiz.

[jhalphen]

Hi Timmy,

Don't get discouraged! i discussed with a fellow VK member & friend about your TR-1010 ailments and we both think that you probably have a cut trace on the printed circuit board.

Get the chassis under a really strong light, use a magnifying glass and very carefully inspect the PCB around the vertical processor IC.

When i do this, i use a paper printout of the board's trace layout + an Ohm meter with a "beep" function - it beeps if you put the 2 test leads in contact to indicate zero Ohms = perfect continuity.

I put one end of the test lead at the start of a PCB track and the other one at its end. If the trace is not cut, the meter beeps.

Good luck,

jhalphen
Paris/France

[timmy]

Originally Posted by jhalphen

Hi Timmy,

Don't get discouraged! i discussed with a fellow VK member & friend about your TR-1010 ailments and we both think that you probably have a cut trace on the printed circuit board.

Get the chassis under a really strong light, use a magnifying glass and very carefully inspect the PCB around the vertical processor IC.

When i do this, i use a paper printout of the board's trace layout + an Ohm meter with a "beep" function - it beeps if you put the 2 test leads in contact to indicate zero Ohms = perfect continuity.

I put one end of the test lead at the start of a PCB track and the other one at its end. If the trace is not cut, the meter beeps.

Good luck,

jhalphen
Paris/France

well that is amazing for you to say because i just started to do just that but have not found anything yet but i will keep on it . i have a fluke dvom with the diode beep that i have been using if the trace follows to the end from start it beeps. well ill have to look for a halogen light,lol really bright and im using a magnafying glass with the small double magnafier in it. ok, ill keep you posted when i find this headache, and thanks again for the verticle scan.

[timmy]

well i am trying but i am just about out of options i cannot find whats wrong with this set. and you see these little sets with the same problem and i just cant believe i cannot find any repair info on this horizontal line problem with these tvs on the web , not one thing comes up in regard to the tr101p. there must be someone out there that has mastered this nasty little problem. its strange when i got it it had no hv nothing on screen but found a bad rectifier for the focus voltage and replaced it and got full hv and focus voltage but was left with the line across the screen. checked the schematic and the loss of this voltage would not have affected any other part of the circuit. so its still a mystery.

[colorfixer]

Did any of the old caps have signs of leakage? I restored my JVC P100 and it was littered with bad caps, and a number of them leaked, taking traces with them. I've seen Panasonic capacitors leak, especially in audio gear such as their micro series components.

Take your time, go through each trace on the schematic and if you have a board layout as well, using a highlighter and you'll likely find the issue sooner than later.

Good luck

[timmy]

Originally Posted by colorfixer

Did any of the old caps have signs of leakage? I restored my JVC P100 and it was littered with bad caps, and a number of them leaked, taking traces with them. I've seen Panasonic capacitors leak, especially in audio gear such as their micro series components.

Take your time, go through each trace on the schematic and if you have a board layout as well, using a highlighter and you'll likely find the issue sooner than later.

Good luck

i went over the traces and it could very well be a flyback but really dont know for sure. as far as caps leaking, no it dont appear any leaked besides i changed all the caps on the deflection board.

[timmy]

well it looks like this tv is for parts because i done everything possible to find whats wrong. i think the fly may be bad or a part of it inside because i checked every resistor both chip and threw hole and whats amazing to me is every resistor was right on even the chip resistors. the damper diode only has b+ voltage on it, 4.8 volts and that dont seem right. so for now is going on the side because im out of things to check.

[jhalphen]

Hi Timmy,

i think the fly may be bad or a part of it inside

No, the flyback is good: you have EHT and a bright trace across the screen, therefore it works.

could it be possible that one of these chip caps are bad if its one responsible for the vertical timing. i dont know if SMD components chips are known to go bad even if they have many years on them.

SMD resistors and capacitors can go bad just like any other component.

i did notice that 2 what i think are chip caps off the vert ic have like corrosion and to fix that is very hard because they are hard to hold and maybe this is where the problem is and i dont know if this corrosion could kill the connection but i'll have to try and get them off and resolder.

OK:
1) reflow solder pads on these corrosion-suspect SMDs
2) check trace continuity with Ohm Meter afterwards.

Show us some closeup photos of the suspected corrosion contacts.

If you choose to remove these SMD caps, do you have a capacitance meter?

Check the vertical winding on the deflection yoke. You have the service manual, locate the pins going to the V coils & check for continuity with an Ohm Meter.

On the vertical deflection IC: use your digital VOM to measure voltages on each of the IC's pins vs ground. Compare with the pin-per-pin voltages on the Panasonic service manual.

If really fed-up: send the TV to Andy in TX, he will fix it for you.

Best Regards

jhalphen
Paris/France

[timmy]

OK:
1) reflow solder pads on these corrosion-suspect SMDs
2) check trace continuity with Ohm Meter afterwards.hi, ok heres where im at i did check the ohms on the yoke even though the schematic dont say what it should be it looks ok the ohms are lower then the other coil which i know they vary between vert and horiz coils. and the corroded look to one of the chip caps i did reflow and did check continuity everywhere. i actually checked every resistor and all check very good and i did remove a few key chip caps and subbed one at a time to see if anything changes on the screen, but nothing i do is making and progress. i notice using my dvom on diode check that one lead on ground and i touch the other to pin 4 on the vert ic the screen jumps like it wants to fill the screen. so it seems to me there is a problem in the sawtooth gen that creates the oscilliations to make the vert work but i dont know where else to go from here. it does seem like a timing cap of sorts that may be bad but i just dont know. it is very difficult to really take these chip caps off and sub another really unless i have the exact one to put back in, and leave in and call that cap changed being the right one. all voltages on both ics are where they should be with the exception of pin 6 on the vert ic which is 4.8 volts and should be 2 volts maybe because the vert is not under load, working... also what puzzles me is the line across the screen is not completly across, it starts on one side and stops about an 1/8 befor the other side. i dont know if using ceramic disc caps as subs would be the same as the chip caps that are in there, but i tried. but if it must be the chip type well then maybe ill have to try and get all these chip caps that are in question.

Check the vertical winding on the deflection yoke. You have the service manual, locate the pins going to the V coils & check for continuity with an Ohm Meter....

On the vertical deflection IC: use your digital VOM to measure voltages on each of the IC's pins vs ground. Compare with the pin-per-pin voltages on the Panasonic service manual.

If really fed-up: send the TV to Andy in TX, he will fix it for you.

Best Regards

jhalphen
Paris/France[/QUOTE]

[crtfool]

I would like to just give Timmy a lot of credit for putting all this time and energy in trying to get this TV working again - most of us would have given up with less than 1/4 the effort that he put in - I myself gave up after the ribbon cable tore. Even though these TV's look simple, they are actually very complex and they are very poorly built from a servicing and component quality level standpoint.

We have all had pieces of equipment that were so challenging that the basic "IT or ME" instinct kicks in and forces us to NOT want to let it beat us.

At this point, I suggest that you purchase another cheap TR-1010p with similar problems and apply all that you have learned to make a fresh start.

Good luck.

PS:

Andy is excellent, and I am sure that he could fix it, but these TVs are a dime a dozen, and the main purpose is for Timmy to have the satisfaction and pride of repairing it himself.

[timmy]

Originally Posted by crtfool

I would like to just give Timmy a lot of credit for putting all this time and energy in trying to get this TV working again - most of us would have given up with less than 1/4 the effort that he put in - I myself gave up after the ribbon cable tore. Even though these TV's look simple, they are actually very complex and they are very poorly built from a servicing and component quality level standpoint.

We have all had pieces of equipment that were so challenging that the basic "IT or ME" instinct kicks in and forces us to NOT want to let it beat us.

At this point, I suggest that you purchase another cheap TR-1010p with similar problems and apply all that you have learned to make a fresh start.

Good luck.

PS:

Andy is excellent, and I am sure that he could fix it, but these TVs are a dime a dozen, and the main purpose is for Timmy to have the satisfaction and pride of repairing it himself.

i did get another 1010 and may try a fresh start. i also have 2 1020 that had problems with the verticle and were both in the ribbon and they work great now after putting jumpers in the ribbon.

[compucat]

I wanted one of those Panasonics for a long time but hearing about all the problems maybe I will pass. I do have the Sony Watchman sets and they seem to be holding up well. Even the ribon cables seem to be strong. I can definitely recommend the FD-20. It is a great performing nicely built set.

[jhalphen]

Hi Timmy,

i notice using my D-VOM on diode check that one lead on ground and i touch the other to pin 4 on the vert ic the screen jumps like it wants to fill the screen. so it seems to me there is a problem in the sawtooth gen that creates the oscilation

I think you're close: have a real hard look at the 1000pf cap between pins 4 and 5 of the AN5760, maybe it's a trivial as a bad GND on pin 5

To help: closeups of the block diagram + application note schematic of the AN5760.

Last document is a high-zoom of the TR-1010P's schematic showing the AN5760.

all voltages on both ics are where they should be with the exception of pin 6 on the vert ic which is 4.8 volts and should be 2 volts maybe because the vert is not under load, working..

Timmy, i don't know what the DC voltage on pin 6 should be but it is the output of the V amp power section driving the deflection coils and the Pana manual specifies 10V peak-to-peak. A VOM reading is meaningless here, the only way to measure this is to see the sawtooth on a Scope (borrow one?)

Hope this helps...

Hi Sandy:
My experience on many of the Panasonic TR-series 1.5" micro-TVs:
TR-1030/1031 always work - built in the second half of the 80s

TR-1010/TR-1020 - before 1984 - a lot of failures, mainly V Scan, no sound, dead or very unsensitive tuners.

Exceptions: TR-1000 nearly always work - better caps!
TR-001, same thing - 1972!

CT-101 shoddy plastics: look at them, they break!
Not really Panny's fault but the people who made the plastics. When new in 1984-1987 they weren't brittle.

Just my 2 Cents....

Best Regards

jhalphen
Paris/France

[compucat]

Why is the circuitry on these handheld sets so complex? One would think that given the small size, simpler designs would be easier to build and service plus be more reliable.

[crtfool]

Originally Posted by compucat

Why is the circuitry on these handheld sets so complex? One would think that given the small size, simpler designs would be easier to build and service plus be more reliable.

These were designed and built in the 1980's when SMD components were just getting started - they really were a marvel of engineering, compactness and even simplicity compared to what was previously available. By the time that the TR-1030p series came out, they already reduced the amount of components considerably - and both sets did exactly the same thing. These are 30 years old - comparable technology in today's world make them look very complex. If they redesigned the same set today, it would most likely contain 1 or 2 VLSI chips and a few discreet components plus push-button switches for Power, Volume and Tuning.
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