Magnovox 32MF231D

[retiredcaps]

Re: Magnovox 32MF231D

Yes, I did use a magnifying lens, there are not a lot of numbers that look like zero, so it has to be a zero or an eight, maybe an R, but I don't think so.

Resistances less than 10 ohms have 'R' to indicate the position of the decimal point (radix point).

http://en.wikipedia.org/wiki/Resistor#SMD_resistors

[TechShui]

Re: Magnovox 32MF231D

Yes, I know what the R stands for, but it doesn't really look like an R, more like an eight.

This is the last letter I'm referring to, so 40R and 400 are both 40 ohms, but an eight would mean 4,000 mega ohm.

EDIT: Took me a dozen tries, but I was finally able to focus the camera in such a way that it gave a clear focused zoom. I think it says 480, that would be 48 Ohms.

[budm]

Re: Magnovox 32MF231D

From logical point of view, they do not have 4000 Mega Ohm resistor, it may as well be a open circuits. I did not follow the post lately to know how this resistor is connected to the circuits.

[TechShui]

Re: Magnovox 32MF231D

Let's get back on track here.

These resistors connect to pin 5 of the 7003 IC.

480 = 2.77k Ohms
273 = 3.4k Ohms
221 = 220 Ohms

The sch that budm attached on page 3, shows it like this:

Pin 5 > 3K09 (3005) > 27K (3007) > 220R (3006) > 1000u 16 cap (2006) > 12VS

What's this mean? The one labeled 480 is actually 3.09K Ohms... ?

And what about the 27K having a reading of only 3.4K, what could diminish it's resistance while in circuit.

[budm]

Re: Magnovox 32MF231D

3K09 (3005): The 3005 is the designator number for this 3k09 resistor, most diagram would have use R3005).
If you look at the Diagram:
2xxx is for capacitor
3xxx is for resistor designator.
6xxx is for Diode
7xxx is for Transistor

But where do you see the 480 in the diagram?

[selldoor]

Re: Magnovox 32MF231D

I have been lazy and not read the thread but is this information any help:
http://www.scribd.com/doc/50623833/2...f231d37TPE1-0U

Again didnt understand all the posts about 40R being the same as 400 etc I thought it would be 40R=40.0 but on smd components the R label is only used up to 10 ohms so that argument seems invalid.
Furthermore I am not now sure if budm is thinking 480 "label" is on the board or the schematic whereas I think TechShui means the "value" printed on the component.

The 480 value on the component in my opinion means that it is a 48ohm resistor which does not show at all on the schematic. As we all know that is not unusual as boards and schematics often differ.

In broksonics pic the component is quite clear tho not readable on screen I suggest you pm him and ask what value is shown on his save any guessing .

[budm]

Re: Magnovox 32MF231D

Yes, I am thinking about the 480 for deisgnator in the diagram which I do not see. The board itself does not seem to have any designator for the resistors at all.

[reckhardt]

Re: Magnovox 32MF231D

TechShui,
I am working on the same board (except 6285.3) as you and have some bad news. The 10 ohm resistor you replaced at what looks like 3U22 was not 3U22. 3U22 is actually the 1206 size resistor labeled "100" close to the last "2" in "3U22" on the board.

The part you replaced with a 10 ohm resistor is actually 2U16 which should be an 0805 size, 1uF, 16V ceramic capacitor.

Also, the resistor that looks like 480 definitely says 488 on my board (see attached). I am bewildered by this as well. It appears to be part 3005, a 3.09k ohm resistor judging by the connections on the board.

EDIT: Here about half-way down, it explains a new resistor code. This explains the 48, but the other 8 must be an A for it to work out to 3.09K.

[selldoor]

Re: Magnovox 32MF231D

WOW -Reckhardt, thanks for registering to tell us- that is a revelation - not come across that coding - doesnt seem to feature in WIKIpedia.

I think you may have tripped at the last hurdle though I think it is a 48B

48 = 309ohms x B (10) = 3090 = 3.09k

[tom66]

Re: Magnovox 32MF231D

http://www.marsport.org.uk/smd/res.htm

48 = 309 ohms
B = 10

= 3.09k ohm

[reckhardt]

Re: Magnovox 32MF231D

Doh! Yes, 48B would make 3.09K. My mistake.

[TechShui]

Re: Magnovox 32MF231D

I have been lazy and not read the thread but is this information any help:
http://www.scribd.com/doc/50623833/2...f231d37TPE1-0U

Again didnt understand all the posts about 40R being the same as 400 etc I thought it would be 40R=40.0 but on smd components the R label is only used up to 10 ohms so that argument seems invalid.
Furthermore I am not now sure if budm is thinking 480 "label" is on the board or the schematic whereas I think TechShui means the "value" printed on the component.

The 480 value on the component in my opinion means that it is a 48ohm resistor which does not show at all on the schematic. As we all know that is not unusual as boards and schematics often differ.

In broksonics pic the component is quite clear tho not readable on screen I suggest you pm him and ask what value is shown on his save any guessing .

Thanks for reminding me about it, I discovered a similar post last month, I shared it in this same thread, post 28.

broksonic suggested I test the crystal IC with a frequency tester (or DMM with that feature). I can see those little grey caps on the output traces for the 1H00 IC. Those caps are indeed smaller than fly shit, I think I'll need a special tip to desolder them... hmm.

But I don't have a capacitance meter either. I guess I will have to get all these tools in order to confirm my suspicions.

TechShui,
I am working on the same board (except 6285.3) as you and have some bad news. The 10 ohm resistor you replaced at what looks like 3U22 was not 3U22. 3U22 is actually the 1206 size resistor labeled "100" close to the last "2" in "3U22" on the board.

The part you replaced with a 10 ohm resistor is actually 2U16 which should be an 0805 size, 1uF, 16V ceramic capacitor.

Also, the resistor that looks like 480 definitely says 488 on my board (see attached). I am bewildered by this as well. It appears to be part 3005, a 3.09k ohm resistor judging by the connections on the board.

EDIT: Here about half-way down, it explains a new resistor code. This explains the 48, but the other 8 must be an A for it to work out to 3.09K.

Thanks for noticing that, I guess I will cannabalize 2u16 from my rev 3 board to replace that component.

[broksonic]

Re: Magnovox 32MF231D

Sorry for being gone so long. Work called me OTR for awhile and when i got back computer was fried. Had a storm come through and must have got it.

I ended up getting a different scaler board. Just installed it today and tv back up and working although havent pluged it into DTV receiver yet but screen comes up and menu does too.

Going to be a few days before i close it up ( need a new card for my other Direct tv receiver) is there anything you want checked while its open with a working scaler board in it?


Forgot to mention that there are 6 or 7 other scalers that supposedly work with this tv. If you want a list of the ones i found let me know. Dont have the list in front of me or i would post them now.

[TechShui]

Re: Magnovox 32MF231D

Hi broksonic,

It looks like I'm too late to take you up on that offer, by now you've probably put the TV back together?

That's OK, I think history has shown us that the most common failure is the crystal IC (1h00) and/or the tiny gray caps.

But please save me your old dead scaler board, I will have some money in my paypal acct next week, and will send you some money if you're willing to ship it to me? You can use the same box the new one came in, just cover it with a new shipping label.

Yours did not have a hole in the smps 12VS chip... so maybe it will be an easier fix, or I can salvage the components to fix mine.

[broksonic]

Re: Magnovox 32MF231D

TechShui, yes i still have the board. PM me a offer (which im sure i will take).

Also had a request for the ALT part numbers for that scaler board so here they are.. ( i havent tried any of these as an alternate, so understand using at your own risk)

313815886271
313815864951
313815866861
313815866881
313815868521
313815868281
313815868211
313815868221
313815866721 (which was my original)

Currently only see one at a fair price on E-bay

http://www.ebay.com/itm/Philips-32mf...item3cc73e1932