HP lcd L1502 15"

[retiredcaps]

Re: HP lcd L1502 15"

The readings your getting with your ohmmeter, the jumping and taking time to settle down makes me wonder if you may have a problem with your DMM leads?

Either that or a "low" battery even though the low battery indicator doesn't come on.

My first initial purchase of the "sort by lowest ebay price" 830b multimeter came with crap test leads. Touching them together on a Fluke 75 shows 0.9 ohms and fluctuation. On a good set of leads, I get steady solid 0.2 or 0.1 ohms.

[leov]

Re: HP lcd L1502 15"

Either that or a "low" battery even though the low battery indicator doesn't come on.

My first initial purchase of the "sort by lowest ebay price" 830b multimeter came with crap test leads. Touching them together on a Fluke 75 shows 0.9 ohms and fluctuation. On a good set of leads, I get steady solid 0.2 or 0.1 ohms.

Hi retiredcaps,

I got a new set of leads and the meter does show 0.2 when I cross them.


I took of my C5707's and tried testing them. Please see the pic. Transistor #2 shows 0.9 no matter how I connect the pins. Transistor #1 shows shows 0.9 between pins B and E. My understanding is that I should not get any reading if I connect pins C and E.

In the picture, black color is my negative lead and red--positive. Please tell me if I am testing correctly.

Thanks guys!!
Leo

[PlainBill]

Re: HP lcd L1502 15"

Hi retiredcaps,

I got a new set of leads and the meter does show 0.2 when I cross them.


I took of my C5707's and tried testing them. Please see the pic. Transistor #2 shows 0.9 no matter how I connect the pins. Transistor #1 shows shows 0.9 between pins B and E. My understanding is that I should not get any reading if I connect pins C and E.

In the picture, black color is my negative lead and red--positive. Please tell me if I am testing correctly.

Thanks guys!!
Leo

You are testing correctly, both are bad.

PlainBill

[leov]

Re: HP lcd L1502 15"

You are testing correctly, both are bad.

PlainBill

Thank you PlainBill

I resoldered all the transformers just to cover my bases. Now I will try to find new 5707s

Does anyone know what other transistors can be used in place of C5707?

[retiredcaps]

Re: HP lcd L1502 15"

I got a new set of leads and the meter does show 0.2 when I cross them.

Please tell me if I am testing correctly.

You are doing it correctly. The transistor is bad.

[retiredcaps]

Re: HP lcd L1502 15"

Does anyone know what other transistors can be used in place of C5707?

ebay.com. Search for c5707. I got mine from "sort by lowest price + shipping" and they work fine.

[leov]

Re: HP lcd L1502 15"

Thank you guys. You have been very helpful and I feel like I am learning a lot!

[leov]

Re: HP lcd L1502 15"

ebay.com. Search for c5707. I got mine from "sort by lowest price + shipping" and they work fine.

I have seen some repair kits on ebay. They include some additional resistor. I remember reading here on the forum something about changing it, but it might have been on the dell monitor. Do you think I will need to do that?

[leov]

Re: HP lcd L1502 15"

it was actually a fuse, not resistor.
Here is the link:
http://cgi.ebay.com/REPAIR-KIT-E172F...item4aa96195f6

[kaboom]

Re: HP lcd L1502 15"

Does anyone know what other transistors can be used in place of C5707?

Yes.

KSD1691GS

Works fine. 512-KSD1691GS at Mouser. They are TO-126.

Replace ALL caps and resolder inverter board around transformers, tuning caps, brightness PWM and AC inlet, as well as any other cracks you see.

-Paul

[leov]

Re: HP lcd L1502 15"

Yes.

KSD1691GS

Works fine. 512-KSD1691GS at Mouser. They are TO-126.

Replace ALL caps and resolder inverter board around transformers, tuning caps, brightness PWM and AC inlet, as well as any other cracks you see.

-Paul

Thanks Paul. Now my next step is buying transistors. I will let everyone know about my results.

[retiredcaps]

Re: HP lcd L1502 15"

it was actually a fuse, not resistor.

Some Benq boards have bad c5707, picofuse, and fu9024. Your board doesn't appear to have the fu9024.

You can test your picofuse to see if it is open or not. A good fuse should measure less than 1.0 ohms.

[leov]

Re: HP lcd L1502 15"

Some Benq boards have bad c5707, picofuse, and fu9024. Your board doesn't appear to have the fu9024.

You can test your picofuse to see if it is open or not. A good fuse should measure less than 1.0 ohms.

Is it ok to test it soldered in?

[retiredcaps]

Re: HP lcd L1502 15"

Is it ok to test it soldered in?

Any type of ohms measurement is always done with power off and device unplugged.

Yes, you can measure the picofuse "in circuit" aka soldered in.

[leov]

Re: HP lcd L1502 15"

I just tried testing it in circuit and it read 0.3 ohms. So I think it is good. Thank you Retiredcaps!

[leov]

Re: HP lcd L1502 15"

Hello Everyone!

Today I received my C5707 transistors. I went ahead and solderd them in and as you can see on the picture I am using my fixed and working monitor to post the update

I changed only one set of C5707's and resoldered the other two. I also resoldered all the transformers. Hopefully this monitor will last me another few years

I am a college student, so I try to save any way I can. I just wanted to say thank you to everyone who helped me fix my monitor (retiredcaps, plainbill, th3, kaboom, alexanna and steve2). I would not be able to do it without you guys. I have learned few things about electronics along the way. So thank you guys again!! You helped me save some money!

sincerely,
leo

[Th3_uN1Qu3]

Re: HP lcd L1502 15"

Good job... Next time look for a bigger screen to fix.

[PlainBill]

Re: HP lcd L1502 15"

Good job... Next time look for a bigger screen to fix.

A very good suggestion. I'm using a 23" KDS wide screen monitor that cost me about $20 - $15 for the non-working monitor and $5 for the caps to fix it. With a little judicious use of your time you could be using a much larger monitor and have made money on the upgrade!

PlainBill

[leov]

Re: HP lcd L1502 15"

Thanks guys

I was looking for some big screens online, but they go for too much. Any suggestions where I can pick some up?

[PlainBill]

Re: HP lcd L1502 15"

Thanks guys

I was looking for some big screens online, but they go for too much. Any suggestions where I can pick some up?

Craigslist, Freecycle, Kijiji, recyclers.

PlainBill