PIC 16F1937 microchip

[Donny2derby]

Apologies for the delay in getting back to you stj. I was working nights last weekend. On second inspection it does appear to be the relay as there’s no 5v DC output from it. A new one has been ordered and is on a slow boat from china as we speak! I’ll let you know the outcome.

[Donny2derby]

Hi all. Hoping someone can help. There is an oil filled heater at work that is not running. The pump that fires the oil is not kicking in.

I've taken the PCB out the panel and found a board that is marked IPD-0018-E

It's receiving 230v ac and the output relay has 5v DC present. The various diodes and resistors etc all check out ok. The only thing seemingly left is the IC labelled as PIC 16F1937.

My question would be. How would I know this is the component causing the issue/how do I test? And should I simply order one and replace it? Or does it need programming...

[Donny2derby]

Sounds like a firmware or flash issue to me. [USER="169795"]lotas[/USER] is your man!lotasSounds like a firmware or flash issue to me. [USER="169795"]lotas[/USER] is your man!

[Donny2derby]

Ok stand down lads.

Cracked screen. And the worst of it is I think I’ve done it!!...

[Donny2derby]

And now without any tape at all the image appears clearer! This is with the link installed you asked me to a few posts back....

[Donny2derby]

Ok [USER="169795"]lotas[/USER] I decided to jump in and attempt tape method and progress has been made.

With the tape on this part of the board I get the below image.lotasOk [USER="169795"]lotas[/USER] I decided to jump in and attempt tape method and progress has been made.

With the tape on this part of the board I get the below image....

[Donny2derby]

Ok mate. Photos of panel tabs below with buffer boards also included.

I hope you can make out the very small amount of damage to the tab I’m referring to.

Should I try tape method? Or do you have a different suggestion?...

[Donny2derby]

Ok mate.

It’s an hour or so until I will retrieve the set from where it’s being kept.

The damage is only very slight. Almost like a small part of one of the tab has become slightly depressed. I wouldn’t imagine it has actually caused any damage to the panel or image.

[Donny2derby]

lotas[USER="169795"]lotas[/USER]


I’ll be getting this TV out of storage later to continue the repair work on it.

Im going to attempt...

[Donny2derby]

😂😂 they’re the easiest, simplest, most basic drive you could imagine! 2 wire control with a potentiometer which utilises an output for the common.

But the advantage they have is that even the simplest of simpletons could figure out how to wire them up.

I had a go at disassembly earlier and they’re the equivalent of a moulded plug on a domestic appliance. They simply can’t be taken apart for the end user to be able to attempt any sort of repair!

Thanks for your input though😁...

[Donny2derby]

Hi all.

We've had a drive fail at work. It says it's outputting according to the LCD screen but when tested there's no voltage at all.

Got it down the workshop for a quick visual but nothing obvious on the caps etc.

Anyone got any experience with these?

Thanks.

[Donny2derby]

I’m not experienced enough to be able to distinguish if it’s only AC on the striped and DC non striped but you will only have AC before the bridge rectifier and DC after that.

[Donny2derby]

A transistor acts as a switch, a diode is there to allow current to only pass in one direction.

A transistor is 3 terminal, diode has 2.

There is a diode in a transistor so that’s why they can be tested in Diode mode using a multimeter....

[Donny2derby]

Diodes don’t have bases, collectors and emitters. They have Annodes and Cathodes. Transistors have Base, collector and emitter terminals.

If you want some proper help it’s best you post up some pictures of all the boards.

[Donny2derby]

lotas[USER="169795"]lotas[/USER] [USER="75051"]Diah[/USER]

Where do you lads suggest I go with this fault finding now? What is next stage of process? Should I check for 12v from Ic1603? I have noticed that...

[Donny2derby]

I’ve ordered the basic model CH2341a. I think this is best place for me to start.

[Donny2derby]

Yes the very first time I powered on Diah. But I also tried twice more before initial disassembly and it did not go to HDMI screen on those 2 next attempts at power on.

Set is no safely secured away in secrecy at work. The next shift returns soon so I need to tidy away haha. Hopefully I can continue the process tomorrow or if not then most definitely can continue with work on it Saturday night onwards when I am on night shift.

[USER="169795"]lotas[/USER] do you think it will be good idea to order CH2341a programmer in mean time in case you recommend software...

[Donny2derby]

Lotas this is excellent. I will do this immediately. Whilst I prepare the jumper kindly explain the purpose of this test.

Ok lotas interesting. The panel goes into bootloop 2 or 3 times then give a maintained and steady backlight. So does this indicate the screen is ok and we should continue with the fault finding?

I have seen in other threads to check for 12v from Ic1603 Ut to buffer boards. But I’m struggling to find a pinout for the Ic.

Exciting progress though!😀

[Donny2derby]

To add to this. When I test the small SMD caps in the area of the board around what I believe to be inductors (marked 2R2) I get good, solid readings with caps that begin to discharge very slowly.

And also the same good readings around the Ic VPMS2SM DA2037 SMPF 019, good, steady readings on the caps in that area.

When I move to test the ones in the area of Ic marked TAS5749M 09W G4 CFC6 the multi meter jumps around between micro and nano farad without ever giving an actual value.

However. I’ve read the forum enough now to understand that Samsung is famously...

[Donny2derby]

Ok team. Let’s see if the finest minds on Badcaps can deliver the goods yet again.

Done the usual disconnect PSU from main board and get good result for steady backlight. Panel buffer boards seem in good health with a very small impact damage to one of them that could have been caused by me during disassembly. However when powered up the backlights still remain on so I’m confident there has been so significant damage to those buffer ribbon cables.

I’ll go through the MB with a fine tooth comb looking for shorts but what are the suggestions in the mean time? ...