Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

[ChakaRaka]

Hi,

Our live-in grandpa has an Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo). Yesterday it would not turn on anymore and I believe the TV is about 2 years old. I am no TV repairman by any means, but am a mechanic and have tinkered with electronics since I was a kid. I have already modified this TV to have a split A/B/A+B audio output (as it came without any output) so he could use headphones at night. Because of that, I thought I should give fixing it a shot before I toss this one out. I have some photo's below of a possible cap failure. There is very little information about this TV because of its strange rebranding. I have searched a lot and came across this forum and was hoping someone could help point me in the right direction. Or even just tell me it is not worth my time.


Thanks.

[tom66]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

Do you have a digital multimeter, as you're a mechanic? That cap is definitely bad. There could be other faults, but it is a definite starting point.

I -swear- I recognise that style of main board, it's very similar to the one in my 24" Bush LCD TV (UK/Europe model.) On mine, a voltage regulator on the main board had failed, which was relatively easy to replace. It caused it to stay stuck in standby and power up only once in a while.

[retiredcaps]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

1) For a number of reasons, please follow my sig file below exactly and remove your inline images and post your pictures using the manage attachments.

2) That one cap is certainly bloated. My standard answer for cap replacement (regulars may skip)

https://www.badcaps.net/forum/showpo...84&postcount=3

edit: Looks like the UK beat me again ...

[Mr Bill]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

It's definitely worth your time. I would do a recap of the entire power supply except for the big cap. It only looks like there are about 8 caps total on that supply so it won't cost whole lot. Have you ever replaced capacitors? Digikey or mouser seem to be the "norm" on ordering parts but i am unsure if they ship to canada. Retired Caps could confirm this since he lives north of the border.

**EDIT**
I got beat by the Brit & Canadian

[retiredcaps]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

Digikey or mouser seem to be the "norm" on ordering parts but i am unsure if they ship to canada. Retired Caps could confirm this since he lives north of the border.

Both do. Digikey charges $8 for a minimum shipping/handling to Canada. As such, I try to "save up" for big orders to ammortize the shipping costs. Digikey does provide, as feedback from people here, quick fast and excellent service.

For Americans, you should be thankful your postage costs and service within your country, in general, are lower than ours.

I recently ordered some electronic components from another province. The postmark was Aug 23 and I didn't receive it until Aug 30. 1 whole week for a 200gram letter.

[ChakaRaka]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

1) For a number of reasons, please follow my sig file below exactly and remove your inline images and post your pictures using the manage attachments.

2) That one cap is certainly bloated. My standard answer for cap replacement (regulars may skip)

https://www.badcaps.net/forum/showpo...84&postcount=3

edit: Looks like the UK beat me again ...

Okay, I am trying to post pictures your way. I have them in an album finally but have no idea how to post them in the original message while editing. I am no noob to forums, nor have I ever had to post photos any other way than through a host. Got a link for this rigamarole?

[retiredcaps]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

Okay, I am trying to post pictures your way.

See

https://www.badcaps.net/forum/showthread.php?t=1868

and thanks. It matters after almost 7,000 posts how it is done if I'm to help people.

[ChakaRaka]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

Are the photos correctly attached now?

[ChakaRaka]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

Do you have a digital multimeter, as you're a mechanic? That cap is definitely bad. There could be other faults, but it is a definite starting point.

I -swear- I recognise that style of main board, it's very similar to the one in my 24" Bush LCD TV (UK/Europe model.) On mine, a voltage regulator on the main board had failed, which was relatively easy to replace. It caused it to stay stuck in standby and power up only once in a while.

I do have a meter. It is at my shop though and not at home. I have a lesser quality one here that might do it, if the battery is not dead.

From my research in searching the PS board part number it comes back as a Viore board. I have never heard of this brand either, so that did not help much. I can get the whole board for about $40 but then I will probably be back revisiting this in another year. This one does not power up at all, only the red standby light is on.

[retiredcaps]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

Are the photos correctly attached now?

Yes, thank you.

[tom66]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

From my research in searching the PS board part number it comes back as a Viore board. I have never heard of this brand either, so that did not help much. I can get the whole board for about $40 but then I will probably be back revisiting this in another year. This one does not power up at all, only the red standby light is on.

Mine eventually stopped powering up too. First it would power up maybe 1 in 5 times. I bought it faulty, so I don't know if it suddenly failed like that or if it progressively got worse.

Can you post a closer picture of the main board? (The lower green board.) I see at least three regulators on there.

[ChakaRaka]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

Mine eventually stopped powering up too. First it would power up maybe 1 in 5 times. I bought it faulty, so I don't know if it suddenly failed like that or if it progressively got worse.

Can you post a closer picture of the main board? (The lower green board.) I see at least three regulators on there.

Yes, it is a little blurry, but I hope this helps. I have looked at some of the online suppliers of capacitors too, but there is so much criteria in the specifications (and numerous brands and types) that it is a bit daunting figuring out which caps I would need, were I to replace all the ones you guys have suggested.

[tom66]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

OK, these are your regulators.

To test:-

Turn TV on so it's stuck in standby.

Set meter to DC 20V.

For each highlighted regulator test each pin (the three pins on one side), if there isn't a pin connected test the metal tab instead. Note them like this;

Pin 1 = 5.123V
Pin 2 = 1.883V
Pin 3 = 0.007V

Note the part # down of the regulator, for example LM1117-33.

[ChakaRaka]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

Tom, thanks for your help. We just had a medical emergency with "grandpa" so I will not have time to look into this for a little while. Spending too much time driving back and forth to the hospital. I will post my findings as soon as I can get to cracking the TV open again.

Thanks again.

[ChakaRaka]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

Okay Tom,

If you are still willing to help, here is what I came up with.

Voltage Regulator "A":
AMS1117
1004
1 - 2.037v
2 - 3.284v
3 - 5.19v

Voltage Regulator "B":
AZ1084S
-ADJE1
017J89
1 - 0v
2 - 0v
3 - 0v

Voltage Regulator "C":
AZ1084D
-ADJE1
01N97
1 - 0v
2 - 0v
3 - 0v

Also when I went to look at replacement caps, I found there were so many with numerous diverse specs. After we sort out the voltage regulators, could you help me narrow down the correct replacement caps?

Thanks so much.

[retiredcaps]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

Voltage Regulator "A":
AMS1117
1004
1 - 2.037v
2 - 3.284v
3 - 5.19v

A is good. My sig file below has a link on how to test a voltage regulator and it tells you why A is good. I suggest you read it.

Voltage Regulator "B":
AZ1084S
-ADJE1
017J89
1 - 0v
2 - 0v
3 - 0v

Voltage Regulator "C":
AZ1084D
-ADJE1
01N97
1 - 0v
2 - 0v
3 - 0v

B and C obviously don't have any input voltage (pin 3). This could be due to the fact that you have bulged caps on the power supply. Or they could be designed not to come on until some function requires it.

I suggest you replace the caps first and then retest the voltage regulators.

It also looks like you might have 2 SMD fuses just below the red/black wires on the main board, but the flash obscures it so I can't be sure. A good fuse should measure less than 1.0 ohms. If they are fuses and blown, that could explain why regulators B and C get no input voltage.

Also when I went to look at replacement caps, I found there were so many with numerous diverse specs.:

My standard answer for people who need help replacing caps with examples (regulars may skip)

https://www.badcaps.net/forum/showpo...84&postcount=3

[ChakaRaka]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

A is good. My sig file below has a link on how to test a voltage regulator and it tells you why A is good. I suggest you read it.

I did read it, that is why the results were noted in the manner that you prefer. I am trying to figure out what I can on my own and save questions for those issues which I can't solve on my own. I also was hopeful when I saw those numbers because although I am not an electrician, my trade deals with DC current a lot so I understand the fundamentals. So I recognized that 5v on one of the pins was a good sign and also understand that the 5v(or largest voltage) would be the input.

B and C obviously don't have any input voltage (pin 3). This could be due to the fact that you have bulged caps on the power supply. Or they could be designed not to come on until some function requires it.

I suggest you replace the caps first and then retest the voltage regulators.

It also looks like you might have 2 SMD fuses just below the red/black wires on the main board, but the flash obscures it so I can't be sure. A good fuse should measure less than 1.0 ohms. If they are fuses and blown, that could explain why regulators B and C get no input voltage.

Okay so am I testing SMD fuses or replacing caps first? My timeline for this repair is getting a little compressed, Grandpa is out of the hospital and wants his TV back. Being unused to soldering such small things, I may just order a replacement power board to get him up and running and repair the original with new caps for when the replacement likely goes south in a similar timeframe (1 year). To test SMD fuses, I am just checking for resistance with power off? Sorry like I said, I know a lot of things, the intimacies of PCB's is not one of them.

My standard answer for people who need help replacing caps with examples (regulars may skip)

https://www.badcaps.net/forum/showpo...84&postcount=3

Fair enough, I will read through another long technical document and see if any of the terminology used matches with the criteria selectable from the parts sellers. I have attempted to figure out which caps would be good replacements already (on a couple suggested online suppliers), but to the "hobbyist" the terminology and specifications are pretty hard to reconcile. Without formal training and experience in the field, the jargon can be a pretty steep learning curve. I spend a lot of my time putting very technical terms and processes into everyday language for my customers, I was hoping someone here could do the same or at least give me some pointers that would have me headed in the right direction.

Thanks.

[ChakaRaka]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

So I started with the bad (bulged) cap to see if I could find a replacement.

The specs from (the outside of) this cap:

AISHI
CD288Z 105C
1014J
25V 220UF

So I went on Digikey and just kept narrowing down criteria with filters until I had a short-list of results after selecting aluminum capacitor. First I selected 25v, then 220uf, then Panasonic, then -40-105C, then radial (after educating myself on the difference between radial and radial-SMD). So then I got concerned with figuring out Ripple Current and ESR because I could not find a comprehensive data sheet for the original cap. But I looked at the 6 results and realized that there were only two Ripple Current's available and the ESR was not listed. So I also noted there were pin spacing differences of 3.5mm and 5mm. The original cap seems to be 3.5 spread to fit the 5mm spacing on the PCB. Height is no issue where this is mounted (within reason). Then finally comes stocking. They only stock the top two items and I had heard "FM" series recommended, however the "EB" is rated at 5,000 hours for an additional 2 cents. See the attached photo for results on Digikey.

So I googled how to determine Ripple Current and realized that I likely do not have enough of the original specs to determine this. So should I look at the other brands that were recommended to see what I come up with there, or does it appear that I have narrowed it down to 2 viable replacements? Sorry if this is tiresome (see also: newbie-ish), but as I alluded to prior, I can do basic wiring and have even assembled some computers but have no formal electrician training. Yet out of the mechanics I have worked with, I am more electrically inclined than most and always eager to learn.

[From link retiredcaps provided:]

You want to replace ALL the electrolytic caps on the board especially if they are poor reliability brands like Capxon. The exception would be the largest filter cap which rarely, but not never, fails.

When you say largest cap, do you mean the big black one (in my case/photos) near the part of the PCB labelled "HOT"? Or do you just mean the largest one in the cluster of caps that are all glued together?

If I can get the hang of specifying replacement caps, then I will feel confident to order the rest of them on my own and attempt to repair the original power supply board. Then I can take my time to not only repair this, but actually upgrade the components and lifespan hopefully. Then if I were to buy a replacement board for the meantime, I could swap it out again later and have a spare or sell the replacement.

[tom66]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

In general, the ESR and ripple current ratings are not crucial. Just get a capacitor from the FM, FR or FC series and you should be good to go.

[ChakaRaka]

Re: Aveis 22" LCD TV LT22AP3 (AKA Daytek/Daewoo)

In general, the ESR and ripple current ratings are not crucial. Just get a capacitor from the FM, FR or FC series and you should be good to go.

Thanks Tom. Do you figure that the other two voltage regulators are likely to be showing 0v because the TV is stuck in standby and only become active when powered up fully? Because this problem showed no symptoms and just would not power up one day, my gut feeling was that it was likely just power supply related. I actually only really opened up the set to check the fuse I had seen in there when modifying it to have audio output. But then I did some googling and found this site and started this thread.