Sharp LC37GD8E c7558?

**quiggy** · 11-23-2014, 12:29 AM

Re: Sharp LC37GD8E c7558?

Nobody ever worked on this model?

**sordids999** · 11-23-2014, 03:55 AM

Re: Sharp LC37GD8E c7558?

https://www.badcaps.net/forum/showthread.php?t=39740

**tom66** · 11-23-2014, 07:46 AM

Re: Sharp LC37GD8E c7558?

Doubt it will be the same capacitor, however it will be possible. That being said, whilst I used to do this I no longer recommend it. I was given the TV back that I did this on, and one the bulb connectors had completely arced and melted the back of the panel, it can be a hazardous modification to do.

**quiggy** · 11-23-2014, 09:14 AM

Re: Sharp LC37GD8E c7558?

Hi Tom thanks for the reply, yeah I figured it could have been a different capacitor, I wasn't wanting it as a long term fix, I was just interested to see what the log would say. It just seems impossible to find any sort of documentation of anyone doing it on this model.

Do you know if I were to just disconnect the faulty lamp(s) if the set would power up without protecting itself? Provided they are what's at fault.

And just in-case anyone was wanting to see the picture I took, I'll add that here it's where I suspected the capacitor to be, somewhere around IC7501.

**selldoor** · 11-23-2014, 11:40 AM

Re: Sharp LC37GD8E c7558?

If posting more pictures can you please use manage attachments so they stay with the thread. Threads dont make much sense when the pics disappear

Attached Files

**tom66** · 11-23-2014, 11:46 AM

Re: Sharp LC37GD8E c7558?

To know which cap you'd need a BD9777 datasheet or schematic for that area or reference schematic for the BD9777.

**quiggy** · 11-23-2014, 11:59 AM

Re: Sharp LC37GD8E c7558?

I'll remember that for next time Selldoor, thanks. I'll have a poke about for a datasheet Tom. If I do manage to come across one, what should I be looking for which would indicate the correct one?

**quiggy** · 11-23-2014, 12:06 PM

Re: Sharp LC37GD8E c7558?

Whist searching google for one, I came across this thread

https://www.badcaps.net/forum/showthread.php?t=33129

I guess this would be the answer for me also? To ground pin 14

**selldoor** · 11-23-2014, 12:27 PM

Re: Sharp LC37GD8E c7558?

In your picture to the left of BD9777 there is a small switching transistor. In the picture it looks in a bad way compared to the others - is it ok?

**quiggy** · 11-23-2014, 12:39 PM

Re: Sharp LC37GD8E c7558?

I think it's just the way the light is hitting it because surely I wouldn't have missed something looking like that, but to be sure I'll take a look at it tomorrow. I'm currently trying to find something that will tell me the which pin is which on the IC

**quiggy** · 11-23-2014, 01:27 PM

Re: Sharp LC37GD8E c7558?

I'm tearing my hair out trying to find any form of diagram for the IC even the inverter board itself, time for a relaxing bath and then maybe get back to the search.

**selldoor** · 11-24-2014, 04:37 AM

Re: Sharp LC37GD8E c7558?

This might help, at least it will give you a laugh

I just hope you remembered to put it on the table muzzle down on the blanket
and didnt get your trivial dangling harness caught up in the cold mattress.

https://translate.google.co.uk/trans...tml&edit-text=

Some where in that there is this: http://4put.ru/pictures/max/628/1929897.jpg

EDIT I will try and attach that in case it vanishes

Attached Files

**tom66** · 11-24-2014, 06:17 AM

Re: Sharp LC37GD8E c7558?

No clear pin you can jumper.
Unfortunately, set will not work without lamp connected, this will trip OVP (over-voltage) warning which is usually what causes the 2sec2black fault (there is also over-current but this usually only relates to bulbs shorting to chassis, which is a rare failure.)

**quiggy** · 11-24-2014, 01:25 PM

Re: Sharp LC37GD8E c7558?

Hahaha, I have no idea how you found that Selldoor, but that was damn hard to try and read whilst trying to make sense of it, which I didn't lol.

I tested the transistor earlier and it came back as fine. I tried disconnecting lamps earlier Tom, I've only just read your post. I tried disconnecting the second inverter board so only the 1 was running, I tried disconnecting the lamps, I read somewhere that holding vol down and chan up would reset the error but nothing worked, all did nothing.

I even had this weird idea that if I disconnected the inverter completely then the IC causing it to protect wouldn't be able to function and that although nothing would display, the light should remain green as if to be working. But that changed nothing either, still turned itself off as normal.

I'm unsure how to proceed now, more research is required it seems, hopefully someone other than the Russians have managed to fix the issue and has documented it online somewhere

**Kilroys** · 11-25-2014, 06:44 AM

Re: Sharp LC37GD8E c7558?

C7558 is located at pin 1 T7502

To bypass the protection OVP in ic BD9777 connect PIN 14 to gnd.
The backlight should light, but no service mode.

To access service mode hold “VOL-“ and “INPUT” keys at same time that AC cord is connected.
Next, hold down the “VOL (-)” and “P ( ▼ )” keys on the set at once.
Using keys (UP/DOWN), go to [LAMP ERROR RESET], using keys (LEFT/RIGHT)
go to [LAMP ERROR RESET]. Finally, press “OK” to pass Lamp errors counter to “0”.

Attached Files

RUNTKA216WJZZ.pdf (1.46 MB, 120 views)

**quiggy** · 11-26-2014, 02:22 AM

Re: Sharp LC37GD8E c7558?

I knew someone out there would know! I'll give this a go later today and let you know how it went. Thanks Kilroys!

**quiggy** · 12-06-2014, 02:26 PM

Re: Sharp LC37GD8E c7558?

So, I attempted the bypass and I broke it. I was already in a pretty bad mood before I started, but due to lack of attention and carelessness on my part, I broke a leg off the IC and then I punched it.

So It's under the table for the foreseeable future.

Thanks for the help guys! I'm sure I'll find another project soon enough.

On another note, does anyone know if there is an electronics servicing course? Like a city and guilds or something, I know years back my dad did one called 224 electronics servicing but I can't find today's equivalent.