32" Goodmans TV

[dumpystig]

Re: 32" Goodmans TV

We have the same boards but somewhat different connections. Can you post a close up pic of your PSU socket area (with plugs connected) and I'll be more able to make a comparison - I can get a better idea when I can compare positions of wires of a particular colour. Cheers

[dumpystig]

Re: 32" Goodmans TV

Here's mine

[tom66]

Re: 32" Goodmans TV

See attached

[dumpystig]

Re: 32" Goodmans TV

Right, to start with you should only have a few outputs from PSU to M/b @ STBY:

PL805:
#10 - 3V37
#11 - ^
#12 - 5V07

And from M/b to PSU @ STBY:

PL803;
#5 - 62mV
#6 - 1V74
#7 - 32V2

All other pins remain low until TV is started either by RC or side button. M/b (VCTP) then initiates STBY_ON_OFF output to PSU, PL804#6 goes low and all other V's (3.3, 5, 12, 24, 34) are then present. Next PL803#1/PL802#12 goes high to start inverter/backlight.

So now @ RUN:

PL801:
pin #1 - NC
pin #2 - NC
pin #3 - NC
pin #4 - 24V3
pin #5 - ^
pin #6 - GND
pin #7 - ^
pin #8 - NC
pin #9 - NC
pin #10 - NC

PL802:
pin #1 - 24V3
pin #2 - ^
pin #3 - ^
pin #4 - ^
pin #5 - ^
pin #6 - GND
pin #7 - ^
pin #8 - ^
pin #9 - ^
pin #10 - NC
pin #11 - 2V46
pin #12 - 3V01 ~ 2V92

PL803:
pin #1 - 3V01 ~ 2V92
pin #2 - 2V47
pin #3 -
pin #4 -
pin #5 - 2V56
pin #6 - 56mV
pin #7 - 33V9
pin #8 - 12V1
pin #9 - GND
pin #10 - ^

PL812:
pin #1 - 5V1
pin #2 - ^
pin #3 - 3V36
pin #4 - ^
pin #5 - ^
pin #6 - GND
pin #7 - ^
pin #8 - ^
pin #9 - ^
pin #10 - 3V34
pin #11 - ^
pin #12 - 5V04

PL813:
pin #1 - GND
pin #2 - ^
pin #3 - 12V1
pin #4 - ^

[dumpystig]

Re: 32" Goodmans TV

The bold values in my last post are what I'm getting on my board, but they are all very close to or the same as the values indicated in the Sanyo training manual.
Also am I correct in assuming you listed your wires the wrong way round on your PL813/

[tom66]

Re: 32" Goodmans TV

The bold values in my last post are what I'm getting on my board, but they are all very close to or the same as the values indicated in the Sanyo training manual.
Also am I correct in assuming you listed your wires the wrong way round on your PL813/

Probably...

Most of my voltages look out of spec, apart from standby.

Maybe it's worth buying a main board and selling the board on if it doesn't fix the problem. I don't stand to lose much as long as I can sell it.

AFAIK my PICkit 2 (microcontroller programmer) can program EEPROMs. I may take the EEPROM out and reflash it. Any idea where to find a .bin file for it?

[dumpystig]

Re: 32" Goodmans TV

I'm wondering if your mod around IC807 may have something to do with it now. If you want me to give you some ref. V's from the PSU just let me know what test points and I'll post them here.


I did search for the .bin file a couple of weeks ago but those things are almost non-existant on the web.

[tom66]

Re: 32" Goodmans TV

I'm wondering if your mod around IC807 may have something to do with it now. If you want me to give you some ref. V's from the PSU just let me know what test points and I'll post them here.


I did search for the .bin file a couple of weeks ago but those things are almost non-existant on the web.

Yes, what does the pin next to Q837 (pin #8) measure at? Mine is bouncing all over the place from 4-5V and that doesn't look good.

If I get a good, working board in, I'll copy the eeprom and post it here for future users.

[dumpystig]

Re: 32" Goodmans TV

Where is the bugger - underneath?

[tom66]

Re: 32" Goodmans TV

Where is the bugger - underneath?

On the top of the board, SG2525A, pin #8. What does yours measure at?

[dumpystig]

Re: 32" Goodmans TV

Got it.
STBY - 1V7~1V8
RUN - 332mV

Good idea with the EEPROM, but I reckon you will have to be certain the replacement board comes from the same manuf./model else it will prob be useless - although I stand to be corrected.

[tom66]

Re: 32" Goodmans TV

Got it.
STBY - 1V7~1V8
RUN - 332mV

Good idea with the EEPROM, but I reckon you will have to be certain the replacement board comes from the same manuf./model else it will prob be useless - although I stand to be corrected.

I think I found one for a Goodmans TV available, anyway it's the main board which decides the "personality" of the set so if it boots up as a Hitachi who cares :P

[tom66]

Re: 32" Goodmans TV

Here's the EEPROM .hex I looked at it and it seems okay, I mean there is data in there like the channel settings (BBC, CH4 etc.) but I have no way of decoding the rest.

I'm going to try erasing it and seeing if it resets it, I doubt it though. [EDIT: Nope, still dead.]

To get around file size limits I had to rename this to a .doc file.

I'm really questioning what part has gone in this set... it's EITHER the PSU or the main board. Right now it's looking a lot like the main board but what would cause this? Software issue? Hardware issue?

[tom66]

Re: 32" Goodmans TV

Okay, I reversed my fix to the TV with pin #8. Now the LED doesn't blink, but we're back to the original issue: it just won't turn on. I had a little difficulty with the circuit, I broke a resistor off the board (R970), but I looked the schematic and it looks redundant to me, so I bridged it. I might replace it later and see if it matters, but I don't think it will.

One pin to look at is SHUTD, as it appears to turn the power supply off. I suspect it must be low to do so. The resistor R970 then might be necessary as it stops the PSU from being held in shutdown while the cap C898 charges. But if we stop the PSU shutting down by removing the transistor which is pulling it down, we might never be able to turn the TV off properly... Ugh! A new PSU is a simple answer, if the main board is good.

Now, we have to debug the slow start circuit and find out why it stops the TV starting properly. Perhaps some protection is activating; if so, why?

I'm most interested in the transistor Q818 as that seems to handle switching the TV on and off, although the switching on and off is also handled by other parts, so it's like everything has to activate in sequence, maybe this was the problem?

There's a lot of protection in this circuit. VFB and Q808 seems to be overvoltage for the 12V rail, tripping on 15V or so. Not bad at all, a good idea in fact. If the caps are aged, the rail might be peaking. So I could look at inhibiting this. Also interesting is the stuff around 5VREF; maybe an undervoltage cut-out?

Problem is, this stuff is all primary side. So I can't probe it with a scope as I risk damaging it. Unless I broke the ground pin off the plug but that is very much frowned upon (and rightly so) as it leaves the chassis of the scope LIVE, and dangerous. I'm limited to a 3 Hz multimeter.

I've attached a screenshot of the part of the circuit we are interested in.

[tom66]

Re: 32" Goodmans TV

Ugghhh!

I was a doofus, I bought a power supply for this TV, didn't read the description - sold as faulty!

Thought it was too good to be true for £10.

Although I will still try to get it working - maybe the fault is similar or easier to fix than this one.

Also - note to self - I need to reflash the eeprom with the original data, maybe it's not booting because of this?

[tom66]

Re: 32" Goodmans TV

Ah - found an EEPROM

http://www.eserviceinfo.com/download...ips_f4238.html

For a Toshiba but 17MB22 chassis.

[tom66]

Re: 32" Goodmans TV

Ah, got my broken PSU today.

Interesting. The transformer for the PFC has been broken right off the board and is quite loose.

The fuse is also blown.

Apart from this though, it seems okay.

Was thinking of removing the PFC fet, and the PFC transformer. Replace the main winding of the transformer with a piece of wire. It wouldn't have PFC any more, but it should work just like mine did, on 328V.

I'll give it a go, haven't got much to lose.

[tom66]

Re: 32" Goodmans TV

Okay, my remove the PFC mod actually seems to have worked.

At least, the PSU didn't explode...

Got standby 5V and 3.3V.

HOWEVER, it still doesn't start... Any ideas?

Across main filter cap I get ~330V in standby and 310V run. I'm hoping the run voltage is high enough; it's a bit on the low side. My last set must have had partially working PFC because run voltage was usually around 330V and standby was about the same. 310V bus corresponds to 219V AC, and the working range is stated at 220-240V.

I need to reflash that EEPROM and see if it fixes it.

[tom66]

Re: 32" Goodmans TV

I was researching the problem I have and it might be a bit more complex than I thought, but at least it is reasonably easy to fix.

This kit here claims to fix the stuck in standby and blinking LED problems. I have either one of those issues. So I am ordering the components featured in the kit and will try and fix it.

http://www.sparedparts.com/products/...k_light_faults

I have another Acoustic Solutions 32" TV I bought for cheap which appears to have the same problem, so if the Goodmans can be fixed maybe the Acoustic Solutions can be too.

[dumpystig]

Re: 32" Goodmans TV

Yep, you sure are having some probs with those Vestel boards - much the same as me ffs. I've had this thing running just fine for days, then I left it off for a few days and on powering up tonight I'm getting the flashing LED crap again. Only today it was a different flash/rate from previous, so up to now I've had four different 'errors' - but nowhere can I find a list of the error codes. But I have narrowed it down to the startup sequence; switch on (from stby) and after a couple of seconds the M/b should chuck out 3V2 on PL003/1 to PL803/1 which in turn goes directly to PL802/12 and supplies the inverter switch-on power. But instead of the 3V2 it's only giving around 2V9, and according to the service manual it should be between 3~5V, and I reckon the 3V minimum is crucial - and maybe there's not enough current either, but the output is too short for me to measure either V or A before it locks out. The backlights illuminate for a split second and then the set locks out and goes into LED flash again. So I'm gona have a closer look at the components supplying the VSUP_3v3_COM on the VCTP.

Back to your set, I think you are having the same probs as I was initially, both my PSU and M/b were playing up. I sorted the PSU and now all the V's are as they should be except the inverter V mentioned above. I'm away for the weekend but I'll get back on it Sunday, and have a closer look at your posts again too.