Philips 37PFL5603D/10 Botched TCON repair - but can I fix it?

[dicky96]

Hi guys
I got a Philips37PFL5603D/10 here with washed out picture that just shouted gamma IC failure. According to the owner it came as part of the bar fittings when he took the business on and was working fine until it then failed a few weeks ago.

Looking at the AS15-F chip it is obvious someone has been in here and replaced this before - and - to be kind to that person... made a 'rather unprofessional' job of it

However if I take the failure at face value then the TV was working after the repair.

The problem, apart from some rather dodgy but probably functioning soldering, is that:
pin 43 has a bit of wire tagged to it going to a nearby cap

pins 42, 41 don't go anywhere (apart from being shorted together) as the pads are missing on the PCB

Pin 40 has the pad missing

Pin 39 has part of the pad present and is quite possibly connected OK but looks a bit dodgy.

Now looking at the datasheet...

Pin 43 is Vdd
Pin 42,41 are NC
Pin 40 is either Vcoml- or NC (it seems to depend whether it is an AS15-E or an AS15-E2 but mine is an AS15-F
Pin 39 is Vcoml+

A replacement TCON even second hand is probably gonna make the repair uneconomical.... but I think I can fix it if I remove the AS15-F, clean up the PCB, resolder a new one then bend up the pins slightly where the missing pads are and solder thin wires to the relevant places on the PCB.

Vdd will be no problem to find, NC I assume I can just leave them floating, it's just the Pin 40 Vcoml- I am not sure about where it should go, or is that pin actually NC as well on the AS15-F?

Oh C240 and C248 look to be missing as well. C246 has obviously been resoldered

Pics attached.

Rich

[will62]

Re: Philips 37PFL5603D/10 Botched TCON repair - but can I fix it?

A top mark of AS15-F is part no. EC5575-F. Two types, E & E2. Your's is type E, pin 40 is not connected. The other, E2, pin 40 is Vcoml-.

Have you thought of cleaning with alcohol and a brush, then refluxing/reflowing. Looks like a lot of crap between the pins. Check for short
between VDD and VSS.

[R_J]

Re: Philips 37PFL5603D/10 Botched TCON repair - but can I fix it?

Like above post, check the other pins, could be just a poor solder connection & resoldering the ic might fix it, worth a try

[Andrew F. Ali]

Re: Philips 37PFL5603D/10 Botched TCON repair - but can I fix it?

Looking at that 'mess', I would opt to purchasing another T-CON Bd., all together.

[freakaftr8]

Re: Philips 37PFL5603D/10 Botched TCON repair - but can I fix it?

I agree. You might find that there are more problems from shorted pins in missing pins that caused other issues within the tcon in which if you were to purchase another AS15 you might find that you just wasted your money because the board has other failures.

But 1st try to rework the other man's poor job and see if maybe you'll straighten it out

[saddle_au]

Re: Philips 37PFL5603D/10 Botched TCON repair - but can I fix it?

If the screen just shows white with a dim image, the screen may not be damaged and the board should be repairable. Looking at the repair job, it will probably not be soldered underneath. Soak the pins quickly in acetone, do not scrub hard. Use chipquik to remove it.

Using a small width solder braid, clean the board using along the pad strokes, not across pads to minimise lifting damaged pads further. Avoid any side to side movement when desoldering and cleaning. Inspect the board carefully after cleaning, any divits under the chip on the base pad can also cause problems seating it back on. The base pad needs to be dead level.

I'd put the schematic for the board up here but I've only got the vf, vc and ve versions of the T370HW02 schematics, not the V402 one.

Solder shorts between legs on the AS15 can seriously hurt the panel. Always test the AS15 for leg to leg shorts after you're finished before powering on. No pin on the chip has adjacent pins shorted to it on the T370 board. Use some non-conductive thermal paste under the chip if you are not going to attempt soldering that pad.

[dicky96]

Re: Philips 37PFL5603D/10 Botched TCON repair - but can I fix it?

Thanks guys. I have successfully replaced AS15 before on other TVs and keep some in stock as it is cheaper to buy several at a time.

As I said, if I take the customers comments at face value then the TV was working after this previous repair. Possibly it has failed again due to bad soldering or the AS15 failed again due to bad heat conduction and the fact Gran Canaria is a sub tropical island!

I have no idea how old this repair is but as the TV came with the fixtures and fittings and this guy has had the bar about 12 months, it must be at least as long as that.

I will clean it up as suggested though I think it may be easier to remove this chip and fit another after cleaning the PCB. I'm just hoping the remaining pads don't lift. Nothing to lose really apart from the small cost of the chip. Also I guess it will be good experience to have a go reworking it. I will mention to the customer that any repair attempt could make it worse.

At the moment the picture is very washed out low contrast, with a light white background all over.

Shame I can't easily check the gamma voltages as, due to the design of the set, it is very difficult to get to the tcon with the lvds and backlight cables still attached to the main and psu boards

Rich

[dicky96]

Re: Philips 37PFL5603D/10 Botched TCON repair - but can I fix it?

A top mark of AS15-F is part no. EC5575-F. Two types, E & E2. Your's is type E, pin 40 is not connected. The other, E2, pin 40 is Vcoml-.

How do I tell which type is E and E2? The ones I have in stock are marked

AS15-F
1625C
B8707218

They have a square metal heatsink tab on the bottom of the chip

Thanks

[will62]

Re: Philips 37PFL5603D/10 Botched TCON repair - but can I fix it?

E2 type has a top mark of AS15E2-F.

[dicky96]

Re: Philips 37PFL5603D/10 Botched TCON repair - but can I fix it?

OK thanks mate.

Well the AS15 came off OK and the PCB cleaned up nicely.

You can see the missing pads and the bit of wire which must be Vdd to pin 43 but all the rest looks good enough. There is no heatsink pad on the PCB under the chip.

[dicky96]

Re: Philips 37PFL5603D/10 Botched TCON repair - but can I fix it?

New AS15 fitted and TV fixed. I found it easier to bend the pin 43 upwards before soldering the chip, then fixing a thin piece of wire from this pin to the adjacent capacitor which was Vdd as continuity checked from the other Vdd pins on AS15.

Anyway another one fixed and an interesting rework experience. Thanks for all who posted.

Rich